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I 






TECHNICAL INSTRUCTION. 

Important Neut Series of Practical Volumes. Edited by 

PAUL N. HASLUCK. Each Book cont^as about i5o pages. 



Pnu>U«Bl Brickwork. 



k. 368 111 



i. CoKlcnli.— English and Flemish 



SarbacD College libxaina 



GIFT OF 

JAMES STURGIS PRAY 



'I'o be kept in the main collection of the 
College Libmy 



f-aiUMra' viiB, voionrB, 




6zK 




h 



TECHNICAL INSTRUCTION VOLUMES {continued). 

Iron, Steel and Firoiroof ConstmcttOIU Con^^n^s.— Introduction. 
Cast Iron Stanchions and Columns. Calculations iq Designing Stanchions and Columns. 
Steel Stanchions, Built and Solid. Foundations for Columns : Loads on Columns. 
Calculating Weights of Stanchions, Girders, etc. Bolts, Connections and Rivets. Joists 
and Girders. Ascertaining Safe Lo^ds on Joists and Girders. Practice of Iron and 
Steel Construction. Ftinciples of Fireproof Construction. Fireproof Columns and 
Stanchions. Fireproof Floors. Fireproof Partitions. Fireproof .Stairs, Roofs and 
Ceilings. Fireproof Curtains, Doors and Windows. Index. 

Textile Fabrics and Tlieir Preparation for Dyeing. Contents. 

—Cotton, Flax, Jute and China Grass. Wool, Silk. Cotton Bleaching. Linen 
BleacJiing. Meicerisini?. Wool Souring and Bleaching. _ Scouring and Bleaching 
Silk. Water. About Dyeing. Index. 

Mordants, Methods and Machinery ujied In Dy einff. Contents. 

— Aluminium Mordants. Iron Mordants. Tin \fordants. Chromium Mordan s. Cop- 
per, Lead, Manganese, etc., Mordants. Tannin as a Mordant and as a Fixing 
Agent for Mordants. Oils, etc. as a Fixing A^ent for Mordants. Fixing Agents and 
Assistants for Mordants. Dyeing Cotton. Dyemg Wool. Lustring and Matching Off 
Mordants. Index. 

Practical Pattern Making. 300 Illustrations. Con/«n/s— Foundry 
Patterns and Foimdry Practice. Toining-up Patterns. Fiaishing Patterns. Circular 
Patterns. Making Core Boxes. Boring Holes in Castings. Patterns and Moulds for 
Iron Columns. Steam-engine Cylinder Patterns and Core Boxes. Worm Wheel 
Pattern. Lathe Bed Patterns. Head Stock and Poppet Patterns, etc. 

Practical Handralllng. 144 Illustrations. Con^^n/s.— Principles of 
Jiandraillng. Definition ot Terms. Geometrical Drawing. Simple Handrails. 
Wreathed Handrails on the Cylindrical System. The Uses of Models. Obuining 
Tangents and Bevels. Face Moulds : their Construction and Use. Twisting the Wreath. 
Completing the Handrail. Orthogonal or Right^angle System of Settui^ Wreathed 
Handrails. Handrails for Stone Stairs. Setimg out Scrolls for Handrails, etc. 

THREE IMPORTANT WORKS FOR MECHANICS. 

Cassell's Cyclopcedia of Mechanics. Edited by 

Paul N. Hasluck. Four Series, each with about 
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" A rich store of information contiibuted by skilled technicians upon 
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Woodworking : A Book of Tools, Materials, and 
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Hasluck. 760 pp., with 2,545 Illustrations, gs. 

The Field s&y^'. — "As a practical treatise on handicraft in wood it is not 
only the most exhaustive hitherto published, but is ip many respects unique. ' 

Metal working : A Book of TooE$i, Materials, and 
Processes for the Handyman;" Edited by PaulN. 
Hasluck. 760 pp., with 2,206 Illustrations, gs. 

The Polytechnic Series, 

Consisting of Practical Illustrated Manuals specially prepared for 
Students of the Polytechnic Institute, Re^^ent Street, London, and 
suitable for the Use of all Students. 

Carpentry Workshop Practice. By C. F. & G. A. Mitchell. 

New Edition. Cloth gilt, is. 6d. 

Practical Plane and Solid Geometry, including Graphic 

Arithmetic. Vol. I. Elbmbntart Stags, By Prof. hT J. Spoonbr, 
C.E. and CI. Cloth gilt, 3s. 

Forty Lessons in Engineering Worjcshop Practice. By 

C F. and G. A. Mitchell, is. 6d. 

Technical Scales. In set of Ten in cloth case. By C. F. 

Mitchell, is. per set. 

Elementary Ghemistry for Science Schools and Classes. 

By Robert Avbv Ward. Crown 8vo, is, 6d. 

Building Construction Plates. A Series of 40 Diawings. 

Cloth, los. 6d. ; or copies of any plate "may be obtained in quantities 
of not less than one dosen, price is. 6d. per d<»en. 

Elements of Machine Construction and Drawing. Fifty 

Sheets. Size x6| x Z94 inches. Complete Set in Paper Wrapper, 4s. 64 
Also published in One volume, bound in cloth, los. 6d. 

CASSELL & COMPANY, Limited, La Belle Sauva^e, London. E.G. 

Face Cover 2] & 



MECHANICS* 



Edited by PAUL N. 

With Numerous Illustrations 6d. net 
Double-Entry Book-keeplnir for Bull ;al | 

Double-Entry Book-keeping^. Account Books for Double ' * i^e ' 

Books. Materials and Jobbing Books. Prime Cost Book. .als. 

Cash Book and Bill Book. Ledger Accounts and Balance 

SinflTlo Entry Book-keeplnK for Builders. oks. 

Commercial Terms. Time Sheets and Pay Sheets. Wages. Day 

Jobbing, Prime Cost and Cash Books. Contracts. System fo 

Bulidere' Work in its Learai Aspects. Contei nates and i 

Contracts. Legal Positions of the Architect and Quantity Udntities and ' 

" Provisions." " Extras." Certificates and Payments. Penaj of Contract 

Agreement. Arbitration. Sub-contracting and other Matters. .me Traffic, &c. 

Demolition of Buildings. Ground Landlora and Building Leases. 
Plasterers' Work. CoM/«n^5.— Materials for Plastering. . used by Plasterers. 

Plastering Ceilings. Plastering Walls. Mouldings and Cornices. . er Casting. Estimating 

and Measuring Plasterers' Work, &c. &c. 
Builders' Quantities. Con^m^s.— Foundations. Sashes. Windows. Doors. 

Floors. Staircases. Roofs. Lead Gutters. Slating. Masonry. Ironwork. I 

CofRn IMakins: and Undertaking. C^n^^n/s.— Special Appliances. Lanca- 
shire Coffins. Southern Counties and other Coffins. Children's Coffins. Aaults' Covered Coffins. 
Polishing Coffins. Inscription Plates. Coffin Furniture. Trimming or Lining. Ornamented and 
Panelled Coffins. Shell and Outer Coffins. Lead Coffins. Undertaking. 

MeasurlnflT Builders' Work. Con/«n^5.— Mathematical Signs, Weights and 
Measures, and Abbreviations. Measuring Carpenters'. Bricldayers' and Masons', Slaters' and 
Plasterers' Work. Measuring Plumbers', Painters'. Glaziers' and Paperha) -rs' Work. Measuring 
Old Buildings. Scottish System of Measuring Builders' Work. 

EstimatinflT for Buiiders' Work. Con^«n/5.— Quantity veyor's Charges. 
Prime Cost and Profit Payments. Form of Contract, &c. Quantity Si yingy The Use of 
Constants in Estimating. Model Set of PreUminaries for Bill of Quantiti etc. 

Buildin^^ Stones. Con^«n^5.— Stone Formation. Quarrying and >ting. Selecting 
and Testmg. Granite. Slates. Schists. Sandstones. Limestones. Weath g. Dressing and 
Polishing. 

Builders' Holstinv Machinery. Qontents,—S'imp\e Lifting 1 de. Winches. 

Crabs. Cranes. Travelers. Motive Power for Hoisting Machinery. 

Road and Footpath Construction. Con/^n/s.— Foundations. Macadam. 

Stone. Wood. Asphalt. Footpaths. 
Timber. Contents.— Grovfth and Structtu-e. Felling. Converting and Buying. 
Measuring. Seasoning. Properties and Defects Preservation. Varieties. 

Ransre and Stove Fixing: and Oven Building:. Con/en/5.— Principles 

of Range Fixing. Points in Range Construction. Close Ficf Range Fixing. Yorkshire Range 
Fixing. Liverpool Range Seitin^. Portable R.inge Fixing. Register Grate Fixing. Setting a 
Washmg Copper. Setting a Brewing Pan. Building Confectioner's Oven. Building Baker's 
Oven. Index. 

Bricks and Brickmakins'* Contents. — Varieties and Qualities of Bricks. 
Brick Earths and Clays. Brick Kilns. Hand Manufacture of Bricks. Manufacture of Roofing 
Tiles. Ridging Quarries, Coping, etc. Index. 

Paperhangrers' Work. Con/en^s.— Introduction. Selecting Wallpapers. 
Sanitary Aspect of Wall Coverings. Paperhangers' Appliances. Estimating Quantity of Paper 
Required for ajob. Hanging Wallpapers. Re-papering, Treating Damp Walls, etc. Varnishing 
Wailpai)ers. Embossed Wall Coverings. Index. 



USEFUL VOLUMES. 

The Book of Photogrraphy i Practical, Theoretical, and Applied. 

Edited by PAUL N. Hasluck. With numerous Illustrations and Working Diagrams. los. 6d. 
Building Construction. By Prof. Henry Adams, M.Inst.C.E. (Examiner 
to the Bjard of Education). Comprising Notes on Materials, Processes, Principles and Practice. 
With more than 2,000 Diagrams and la Full-page Plates. Cloth, 7s. 6d. net. 

Notes on Alternate Currents "For Students. By Hakold H. Simmons, 

A.M.I.E.E., Lecturer on Electro-Tectinics and Senior Demonstrator at Finsbury Technical 

College. Illustrated, is. 6d. net. 
Practical Electricity. Completely rewritten by W. E. Ayrtok, F.R.S., &c. 

Current, Pressure, Resistanch, energy, power, and cells.' with 247 Illustrations. 

7s. 6d. 
Lathe Construction. By Paul N. Hasluck. 24 Coloured Plates drawn to 

scale. 4d. each, or 6s. per set 

Architectural Dra^nrin^. By R. Phen6 Spiers. With a6 Plates. 8s. 6d. net. 
Cheap D^nrellinfl^s. Edited by Paul N. Hasluck. With numerous Plans 
&c. IS. net. 

CASSELL & COMPANY, Limited, La Belle Sauvage, London^ E.G. 



•i 

J. 

'v- 3 



. I 
• ' 1'' 



J .1 



•XC 



SAOTmHY CONSTRUCTION 



•fV 



IN BUILDING 



TECHNICAL INSTRUCTION 
MANUALS 



Bdited by PAUI. N. 

With numeroui niustratiotu in the TexU Each Book eontaint about tOO panes, 

crown Svo. Cloth, 8$, each. 

Practical Staircase Joinery. 

Practical Metal Plate Work. 

Practical Gas Fitting. 

Practical Draughtsmen's Work. 

Practical Graining and Marbling. 

Painters' Oils, Colours, and Varnishes. 

Practical Plumbers* Work. 

Practical Handrailing. 

Practical Pattern Making. 

Practical Brickwork. 

Practical Painters' Work. 

Boot and Shoe Pattern Cutting and Clicking. 

Sanitary Conveniences and Drainage. 

Iron, Steel, and Fireproof Construction. 

Sanitary Construction in Building. 

Textile Fabrics and their Preparation for Dyeing. 

Mordants, Methods, and Machinery used in Dyeing. 

Colouring Matters for Dyeing Textiles. 

Iron : its Sources, Properties, and Manufacture. 

Greenhouse and Conservatory Construction and Heating. 

other Volumes in preparation. 

OASSKLL AND COMPANY, LiMmeo, London: Paris, 
New York dk MeUxmrne. 



SANITARY CONSTRUCTION 
IN BUILDING 

WITH NUMEROUS &VGRAVINGS AND DIAGRAMS 



EDITED BY 

PAUL N. HASLUOK 



CASSELL AND COMPANY, Limited 

LONDOS, PARIS, NEW YORK <t- MELBOURNE, MCMVI 



r" \ ^^ f^r HARVARD COLLEGE LIBRARY 

JAMES 8TURGIS PRAY 



PREFACE. 



Sanitary Construction in Building contains, in a form 
convenient for everyday use, a comprehensive digest of infor 
mation, contributed to Building World, one of the weekly 
journals it is my fortune to edit, and supplies concise infor- 
mation on the general principles and practice of the subject 
on which it treats. 

It may be said that the matter contained in this book 
consists substantially of articles written by Mr. H. Gilbert 
Whyatt, A.M.LC.E., m.r.san.l, Borough Engineer of Grimsby. 
[Formerly Deputy Borough Engineer of Sal ford, Lecturer on 
Sanitary Science at Owens College, Victoria University, Man- 
chester, and at the Koyal Technical Institute, Salford.] 

Headers who may desire additional information respecting 
special details of the matters dealt with in this book, or 
instructions on any building trade subjects, should address a 
question to the Editor of Building World, La Belle Sauvage, 
London, E.C., so that it may be answered in the columns of 
that journal. 



P. N. HASLUCK. 



La Belle Sauvage^ Londorit 
September, 1906. 



CONTENTS. 

^ 

CHAPTER PAGK 

I. — Introductory 9 

II. — Soils, Subsoils, and Sites . . ... . .14 

III. — Materials of Construction 36 

IV. — Footings, Foundations, and Damp-proof Courses . 45 

V.'-Stability of Walls ....... 67 

VI.— Roofs 79 

VII. — Floors, HeaTths, and Staircases . . . . 87 

VIII. —Air Space and Ventilation 106 

IX.—A Typical Dwelling 137 

Index , , , , , 156 



LIST OF ILLliJSTRATIONS. 



FIG. PAGE 

1.— Subsoil Drainage, Section . 26 
2.— Subsoil Drainage, Plan . 26 
3.— Position of Subsoil Pipe- 
drain 27 

4.— Operi-jointecl Pipe-drain, 

Surrounded with Gravel . 27 
S, 6.— Methods of Trapping 

Drain Outlets ... 28 
7.— Obstructioii of Subsoil 

Water ... .28 

8, 9.— Diverting Down-hill Flow 

of Water, Section and Plan 29 
10. — Obstructed Rain-water Bed 

to Porous Strata ... 29 
11.— Foundation on Arches to 

avoid Subsoil Air and 

Water 30 

12. — Foundation on Concrete Bed 

to avoid Subsoil Air and 

Water 30 

13.— Ventilation of Space under 

Bottom Floor . . .31 
14.— Good and Bad Positions of 

Soldiers' Huts ... 34 
15. — Improved Construction and 

Position of Lower Huts . 34 
16.— Healthy and Unhealthy 

Sites for Houses . . .35 
17.— Jennings' Old Pattern 

Bonding Brick ... 42 
18.— Jennings' 1891 Bonding 

Brick 42 

19.— Doulton's Bonding Brick . 42 
20.— Wrought-Iron Bonding Tie . 42 
21, 22.— Wrought-iron Bonding 

Ties 42 

23.— Section of Lead-covered 

Beam 43 

24, 25.— Hollow-built Walls 

Filled with Asphalt . . 44 
26.— Footings for 9-ln. Wall . 45 
27.— Footings for 14-in. Wall . 45 
28.— Footings for 18-ln. Wall . • 46 
29. — Footings on one Side of 

Wall only .... 46 
30.— Footings without Set-offs . 46 
31.— Footings added to Existing 

Work 48 

32.— Pile with Timber Cross- 
head 47 



FIG. PAOB 

33.— Pile with Steel Crosshead . 47 
34.— Brick Pillar on Cutting 

Ring 48 

35.— Concrete Foundation in Soft 

Ground 48 

36.— Wall Foundation Formed 

by Flagstones . . .49 
37.— Damp-proof Course with 

Floor above Ground Level 52 
38.— Damp-proof Course with 

Floor Level with Ground . 52 
39.— Damp-proof Course with 

Floor below Ground Level 52 
40.— Taylor's Original Damp- 
proof Course .... 53 
41.— Taylor's Improved Damp- 
proof Course Tile. . . 53 
42.— Doulton's Damp - proof 

Course 53 

43.— Broomhall's Damp - proof 

Course Tile .... 53 
44-46.— Examples of Dry Areas 

for Keeping out Damp . 54 
47.— Internal Wall 25 ft. high 

and 30 ft. in Length . . 57 
48.— Internal Wall 25 ft. high 

and over 30 ft. in Length . 57 
49.— External Wall 25 ft. high 

and over 30 ft. in Length . 57 
50.— Internal Wall 25 ft. to 30 ft. 

high, not exceeding 35 ft. 

in Length . . .57 

51, 52.— External Walls 25 ft. to 

30 ft. high, not exceeding 

35 ft. In Length ... 57 
53.— Internal Wall 25 ft. to 30 ft. 

high and over 35 ft. in 

Length 57 

54.— Internal Wall 30 ft. to 40 ft. 

high, not exceeding 35 ft. 

In Length . .58 

55.— External Wall 30 ft. to 40 ft. 

high, not exceeding 35 ft. 

in Length .... 58 
56.— External Wall 30 ft. to 40 ft. 

high and over 35 ft. in 

Length 58 

57.— Internal Wall 30 ft. to 40 ft. 

high and over 35 ft. in 

Length 58 



8 SANITARY CONSTRUCTION IN BUILBINO. 



FIG. PAGE 

58, 59.— Internal and External 
Walls 40 ft. to 50 ft. high, 
not exceeding 30 ft. in 
Length 59 

60, 61.— External and Internal 
Walls 40 ft. to 50 ft. high, 
not exceeding 45 ft. in 
Length 59 

62, 65.— Internal and External 
Walls 40 ft. to 50 ft. high 
and over 45 ft. in Length . 59 

64, 65.— Internal and External 
Walls. 50 ft. to 60 ft. high, 
not exceeding 45 ft. in 
Length 60 

66, 67.— Internal and External 
Walls 50 ft. to 60 ft. high 
and over 45 ft. in Length . 60 

68, 69.— Internal and External 
Walls 60 ft. to 70 ft. high, 
not exceeding 45 ft. in 
Length 61 

70, 71.— External and Internal 
Walls 60 ft. to 70 ft. high 
and over 45 ft. in Length . 61 

72, 73.— Internal and External 
Wall 70 ft. to 80 ft. high 
and over 45 ft. in Length . 62 

74, 75.— External and Internal 
Walls 70 ft. to 80 ft. high, 
not exceeding 45 ft. in 
Length 62 

76, 77.— Internal and External 
Walls 80 ft. to 90 ft. high, 
not exceeding 45 ft. in 
Length 63 

78, 79.— External and Internal 
Walls 80 ft. to 90 ft. high, 
and over 45 ft. in Length . 63 

80, 81.— Internal and External 
Walls 90 ft. to 100 ft. high, 
not exceeding 45 ft. in 
Length 64 

82, 83.— External and Internal 
Walls 90 ft. to 100 ft. high 
and over 45 ft. in Length . 64 

84.— Party Wall Corbelled out 

and Carried above Eaves . 70 

85, 86.— Construction of Party 
Walls, as Laid down in 
M.B.L. Nos. 33 and 34 . 72 

87.— Galvanised Corrugated Iron 82 

88.— Basement Floor Laid below 

Mean Water Level . . 93 

89.— Solid Plank Floor ... 94 

90.— Ordinary Skirtings . 96 

91.--Skirting Made of Portland 

Cement 96 

92.— Section through Hearth 

showing Brick Trimmer . 97 

93-95.— Averaging Height of 

Room . . .102, 103 



FIG. PAGE 

96.— Back-to-back Houses in 

Courts 107 

97.— House of Smallest Possible 

Type 112 

98.— Four-roomed House . .112 
99.— House of Three Rooms on 
Ground Floor, with Bed- 
rooms and Attics above . 113 
100.— Ventilator through Ceiling 

and Roof . .125 
101.— Natural System of Ventila- 
tion 128 

102.— Air Current Direct from 

Inlet to Outlet . . .130 
103.— Air Inlet over Lintel of 

Door 130 

104.— Air Holes Pierced through 

Window Bars . . .130 
105.— Air Inlet at Window Bars. 130 
106.— Tobin Tube Inlet . . .131 
107.— Sheringham Inlet . . 131 
108.— Vent Tube from Centre of 

Ceiling 131 

109.— Blackman Air Propeller . 132 
110.— Down and Up Currents in 

Large Shafts . . . .133 
111.— Top Ventilation with Two 

Tubes ..... 134 
112.— Top Ventilation with Con- 
centric Tubes . . .134 
113.— House Planned Parallel 

with the Compass Points. 138 
114.— House Planned Diagonal 

with the Compass Points . 138 
115.— Street Planned North and 

South 139 

116.— Street Planned East and 

West 139 

117.— Ground Plan of 14-ft. 4J-in. 

House 140 

118.— First Floor Plan of Fig. 

117 140 

119.— Ground Plan of 16 ft. 9-in. 

House 141 

120.— First Floor Plan of Fig. 

119 *. 141 

121.— Ground Plan of House 

costing £150 . .144 

122.— First Floor of Fig. 121 . 144 
123.— Section of Fig. 121 . . 145 
124.— Ground Plan of 14-ft. 6-in. 

House 146 

125.— First Floor Plan of Fig. 

_ 124 ^ 146 

126.- Section of Fig. 124 . 147 

127.— Plan of Ground and First 

Floor of 12-ft. 9-in. House. 148 
128.— Section of Fig. 127 . 149 

129.— Ground Plan of 17-ft. 1-in. 

House 150 

130.— First Floor Plan of Fig. 

129 ^.151 

131.— Section of Fig. 129 . . 152 



SANITARY CONSTRUCTION 

IN BUILDING. 



CHAPTER I. 

INTRODUCTORY. 

It is proposed in this manual to deal with Sanitary Building 
Construction only so far as regards the sanitary inspector 
and the Public Health Act (p.h.a.). The Model Bye-laws 
M.B.L. of the Local Government Board (l.g.b.) have been 
quoted in full wherever necessary, and explanations of the 
various clauses and provisions have been given, with a view 
to making the duty of both the builder and the sanitary 
inspector perfectly clear on all the points involved. It is 
desirable, however, for anyone taking up the subject to 
purchase copies of the p.h.a. and the m.b.l., published by 
Messrs. Wyman & Sons, Fetter Lane, London, E.C. Messrs. 
Knight & Co., 227 and 239, Tooley Street, London, S.E., 
publish the various p.h.a., 1875 to 1892, in one volume and 
well indexed, at 6s. 6d. ; they also publish the " Annotated 
Model Bye-laws," indexed and illustrated, the seventh edition 
of which was issued in 1905 at 16s. net. This latter volume 
contains a number of additional and alternative clauses, 
these being quoted or referred to, as the need arises, in the 
present manual. 

Sanitary engineering, sanitary inspection, and p.h.a. are 
not modem innovations ; they are merely a revival of very 
ancient legislation. We find within the first five books of 
the Old Testament the sanitary laws as to scavenging, pure 
water, clean food, and bodily cleanliness, as observed by 
the Israelites 3,300 years ago. " The health of the people 
is the highest law," wrote a Latin author about 2,000 years 
ago ; and in his time the law was observed, for we still find 



10 SANITARY, G0N8TBUGTI0N IN BUILDING, 

in Rome the remains of the great sewers, the aqueducts, 
and other great sanitary engineering schemes. 

In a paper on " Sanitary Houses and How to Select 
One," F. A. Bond, m.b., writes : "In the olden days a habita- 
tion was merely a place to dwell in. In primeval times it 
might be a cave, with a f^w rough portions of rock placed 
before the entrance to act as a door ; or it might have been 
a hole in the ground, with simply a few branches' of trees 
covered over it to act as a roof ; or it might have been an 
abode built in a tree, composed of nothing but branches 
twisted together, after the manner of a bird's nest, and 
probably suggested by it. All these, in difierent climes, 
have been used as the home of man." But necessity and 
the progress of civilisation demanded a means of shelter 
more adaptable to varying circumstances, and the one- 
roomed hovel was built of " rough stones piled one on the 
other in rude, unshapely masses, the crevices being filled 
with mud to keep out the wind and rain. Advancing further, 
the single room was made into two, then one was built above 
the other, mud was replaced by mortar, and bricks took 
the place of stones. One change brought another, and the 
house grew and increased step by step and stage by stage." 

But, while civilisation increased, and in nearly every 
science rapid advances were made, the science of Sanitary 
Building Construction lagged woefully behind. Houses were 
built without reference to their surroundings, and regardless 
of proper means of drainage ; no attention was paid to 
circulation of air, nor to the nature of the subsoil ; and 
as dwellings became more crowded in the vicinity of towns, 
insanitary conditions increased both in number and in in- 
tensity. The state of towns became so bad that in 1842 
a Royal Commission was appointed to inquire into the con- 
dition of the housing of the poor with regard to the drainage 
and water supply of towns. The inquiry was long ; the 
revelations were appalling ; and the result was the passing 
of the P.H.A., 1847. This Act was amended many times, 
and the Act and amendments were consolidated in 1875, 
as the P.H.A., 1875. Over a dozen Acts amending it, and 
more than a score of Acts extending it, have been passed 
since then. 

Various Local Governpient Acts have divided the country 



INTBODUGTOBY. 11 

up into districts, each with its elected body, whose function 
it is to secure the observance of the " supreme law — the 
health of the people," as set forth in the p.h.a. 

An army of officials is employed in carrying out the 
duties laid upon the local authorities, and an army of in- 
spectors is also employed to detect infringements of the 
Acts on the part of property-owners and occupiers. Until 
within the last few years anyone * was thought competent 
to fill the position of a sanitary inspector ; but at the present 
time, although the law is silent as to the inspector's qualifi- 
cations, there is hardly a local authority in England which 
does not insist that applicants for the position shall possess 
a certificate of competency granted by some recognised 
examining body. 

It will be found that the Acts do not themselves contain 
provisions as to the method of construction, but merely 
give power to Local Authorities to make bye-laws on these 
matters, which bye-laws must receive the sanction of the 

L.G.B. 

§ 157 of the P.H.A., 1875 (38 & 39 Vict. c. 55), provides 
that " every Urban Authority may make bye-laws with 
respect to the following matters ; that is to say, 

" (1) With respect to the level, width, and construction 
of new streets, and the provisions for the sewerage 
thereof ; 

" (2) With respect to the structure of walls, foundations, 
roofs, and chimneys of new buildings, for securing 
stability and the prevention of fires, and for pur- 
poses of health ; 

" (3) With respect to the sufficiency of the space about 
buildings to secure a free circulation of air, and 
with respect to the ventilation of buildings ; 

" (4) With respect to the drainage of buildings, to water- 
closets, earth-closets, privies, ashpits, and cesspools 
in connection with buildings, and to the closing 
of buildings or parts of buildings unfit for human 
habitation, and to the prohibition of their use for 
such habitation : 

" And they may further provide for the observance of 
such bye-laws by enacting therein such provisions as they 
think necessary as to the giving of notices, as to the deposit 



12 SANITARY CONSTRUCTION IN BUILDING. 

of plans and sections by persons intending to lay out streets 
or to construct buildings, as to inspection by the Urban 
Authority, and as to the power of such Authority (subject to 
the provisions of this Act) to remove, alter, or pull down 
any work begun or done in contravention of such bye- 
laws." 

It would appear, after superficial consideration of the 
matter, that the only thing necessary to secure Sanitary 
Construction throughout the country would be for the l.g.b. 
to draw up a model code of Building Regulations and to 
enforce them. This they did, so far as the above section 
gave them power. It was found during succeeding years 
that bye -laws on other subjects were necessary, and in the 
p.H.A. Amendment Act, 1890, it is provided as follows {§ 23) : — 
" 23.— (1) § 157 of the p.h.a., 1875, shall be extended 
so as to empower every Urban Authority to make bye-laws 
with respect to the following matters ; that is to say : — 
" The keeping water-closets supplied with sufficient water 

for flushing. 
" The structure of floors, hearths, and staircases, and 
the height of rooms intended to be used for human 
habitation ; 
The paving of yards and open spaces in connection 

with dwelling-houses ; and 
The provision in connection with the laying out of 
new streets of secondary means of access where necessary 
for the purpose of the removal of house refuse and 
other matters. 
" (2) Any bye-laws imder that section as above extended 
with regard to the drainage of buildings, and to water-closets, 
earth-closets, privies, ashpits, and cesspools, in connection 
with buildings, and the keeping water-closets supplied with 
sufficient water for flushing, may be made so as to affect 
buildings erected before the times mentioned in the said 
section. 

" (3) The provisions of the said section (as amended by 
this Act), so far as they relate to bye-laws with respect to 
the structure of walls and foundations of new buildings for 
purposes of health, and with respect to the matters men- 
tioned in sub-sections (3) and (4) of the said section, and 
with respect to the structure of floors, the height of rooms 



(( 



(( 



INTBODUGTOBY. 13 

to be used for human habitation, and to the keeping of water- 
closets suppKed with sufficient water for flushing, shall be 
extended so as to empower rural authorities to make bye- 
laws in respect to the said matters, and to provide for the 
observance of such bye-laws, and to enforce the same as 
if such powers were conferred on the rural authorities by 
virtue of an order of the l.g.b. made on the day when this 
part of this Act is adopted ; and § 158 of the p.h.a., 1875, 
shall also apply to any such authority, and shall be in force 
in every rural district where this part of this Act is adopted. 
" (4) Every Local Authority may make bye-laws to 
prevent buildings which have been erected in accordance 
with bye-laws made under the p.h.a. from being altered in 
such a way that if at first so constructed they would have 
contravened the bye-laws." 



14 



CHAPTER II. 

SOILS, SUBSOILS, AND SITES. 

Although the sanitary inspector is very seldom called upon 
to report as to the fitness of a site for the erection of a row 
of cottages or a group of villa residences, he is frequently 
consulted at a later period, when mysterious diseases break 
out, or provisions putrefy within a few hours after being 
placed in the larder, or water shows itself in the basement, 
or peculiar odours are detected. It is proposed in this chapter 
to deal with the question of soils, subsoils, and sites, with 
reference to their suitability for building purposes, with 
remediable defects and incidental defects in sites, and to 
discuss the views expressed by the l.g.b. and the Houses of 
Parliament on the whole question. 

In determining the suitability of a site, it is not necessary, 
however desirable, to possess more than a smattering of the 
science of geology, and it is palpably impossible here to do 
more than mention the chief points of the science of the 
earth's crust. 

A geologist will hear nothing of soils and subsoils — to 
him these are rocks ; whilst in ordinary language " rock " 
is generally understood to mean a characteristically hard 
substance, the geologist employs the term to designate 
mineral masses of all kinds, whether hard or soft. To him, 
clays and sands are rocks quite as much as are granites and 
jiTbles. For our present purpose, however, it is deemed 
better to use the words in their ordinary sense, calling these 
soft rocks by their ordinary names, or including them gener- 
ally in the term " subsoils," as occasion requires ; and using 
the term " soil " to mean the humus y or the uppermost layer, 
in which may be found an admixture of vegetable and animal 
matter with the minerals. 

Rocks are divided by the geologist into three main classes : 
(1) The igneous, or those formed by fire; ^(2) the aqueous, 
or those formed by water ; and (3) the metamorphic, con- 



SOILS, SUBSOILS, AND SITES. 15 

sisting of either of the foregoing, materially altered in character 
by the action of other elements. There is a fourth class, 
the seolian, formed by the wind blowing accumulations of 
loose material into favourable spots, but they do not play 
a conspicuous part in geology ; we have examples of them 
in the sandhills found by the margin of the sea. 

Rocks of the igneous class, which are rarely found near 
the surface in populated districts, comprise the granites, 
basalts, trap, lava, and other volcanic or plutonic rocks ; 
neither are we much concerned with the metamorphic rocks, 
which comprise the marbles, slates, and others of similar 
composition. 

The aqueous or sedimentary rocks — that is, those formed 
by the action of the water — ^include the sandstones, lime- 
stones, sand, chalk, clay, etc. ; and these are again divided 
into three main classes, namely, the siliceous, or sandstones ; 
the calcareous, or limestones ; the argillaceous, or clays. 
These form the greater portion of the subsoil with which 
the sanitary engineer has to deal, and a little space must 
be devoted to considering them. 

The physical characteristics of each of these classes of 
aqueous rocks differ considerably ; hence their varying 
degrees of fitness and suitability, or the reverse, as building 
sites, the sands being exceedingly permeable, loosely com- 
pacted, and light, the clays extremely dense, impervious, 
and heavy ; and between the two extremes there are almost 
infinite gradations of density and porosity. 

There is one geological point that should be specially 
noticed : The various strata which go to make up the earth's 
surface are superimposed one upon the other in a certain 
definite order, which is never reversed. A particular stratum^ 
or a whole series of strata may be absent from the seri( 
but the order in which they are found may be regarded^s 
invariable. 

There remains for consideration another isoil^hich, 
although it finds no place in manuals of geology, neivertheless 
is of imiversal occurrence in this country, /fond 'causes the 
sanitarian more trouble than all other rocks and soils com- 
bined. The allusion is to " tipped " land, or " made 
ground," as it is indifferently called. There ure in almost 
every town large tracts of land lying below the level of the 



16 SANITARY GONSTBUGTION IN BUILDING. 

town. Perhaps these may have been pits out of which clay 
for brickmaking has been removed, and these inequalities 
may have been filled up with whatever happened to be avail- 
able — with brickbats, cinders, the material dug out of other 
foundations, and not infrequently with much less innocent 
substances than these, such as road scrapings, the contents 
of ashpits and middens, market refuse, fish and slaughter- 
house offal, vegetable and animal refuse of every description ; 
in other cases, chemical or trade refuse of various kinds has 
been employed. Abuses of this sort are now rendered almost 
impossible, if the law is enforced, but the duty of prevention 
rests with the sanitary inspector, who derives his authority 
from § 49 of the p.h.a., 1875, in Urban Districts. The section 
reads as follows : — 

" § 49. Where in any Urban District it appears to the 
Inspector of Nuisances that any accumulation of manure, 
dung, soil, or filth, or other offensive or obnoxious matter, 
ought to be removed, he shall give notice to the person to 
whom the same belongs, or to the occupier of the premises 
whereon it exists, to remove the same ; and if such notice is 
not complied with within twenty-four hours, the manure, 
dung, soil, or filth, or matter referred to, shall be vested in 
and be sold or disposed of by the Urban Authority, and the 
proceeds thereof shall be applied in payment of the expenses 
incurred by them in the execution of this section ; and the 
surplus (if any) shall be paid on demand to the owner of 
the matter removed. 

" The expenses of removal by the Urban Authority of 
any such accumulation, if and so far as they are not covered 
by the sale thereof, may be recovered by the Urban Authority 
in a summary manner from the person to whom the accumu- 
lation belongs, or from the occupier of the premises, or (where 
t^.re is no occupier) the owner." 

'^his gives an inspector complete power in an Urban 
District to cause any accumulation of offensive matter to 
be removed. § 91 applies to both rural and urban districts : 
" For the purposes of this Act . . . (4) any accumu- 
lation or deposit which is a nuisance or injurious to health 
. . . shall be deemed to be nuisances liable to be dealt 
with summarily in manner provided by this Act." 

Succeeding clauses, §§ 92 to 111, show what steps may 



S0TL8, SUBSOILS, AND SITES. 17 

be taken by the inspector and the Sanitary Authority to 
abate the nuisance, and recover the cost if the occupier 
or owner does not carry out the work. Inspectors should 
be thoroughly conversant with every word of these twenty- 
one sections. 

It is quite possible that the deposits of foul matter may 
have been made in the past, before the appointment of an 
inspector, or before the Sanitary Acts began to be so rigorously 
carried out as at present ; and it rests with the inspector 
to prevent such land being used as sites for the erection of 
dwellings. 

" Much of this material is in a state of putrefaction, 
and it has been found by experiment that the organic putre- 
fiable substances do not entirely disappear even in three 
years' time from their first being laid down. Such ground 
as this is the very worst upon which houses could be built, 
and yet it is very common in the suburbs of all towns, and 
is often the subject of alluring advertisements of ' eligible 
sites for buildings.' " — Kansome, " Soils and Sites," p. 7. 

In consequence of a Report by Drs. Parkes and Sander- 
son on the sanitary condition of Liverpool, the l.g.b. in 
1877, in their m.b.l. respecting new streets and buildings, 
framed a clause which now reads as follows : — 

M.B.L. No. 10 : "A person who shall erect a new building 
shall not construct any foundation of such building upon 
any site which shall have been filled up with any material 
impregnated with faecal matter or impregnated with any 
animal or vegetable matter, or upon which any such matter 
may have been deposited, unless and until such matter 
shall have been properly removed, by excavation or other- 
wise, from such site." 

This bye-law, however, was only in force in a few towns 
in the kingdom ; and progress being found too slow. Parlia- 
ment consequently, in the p.h.a. Amendment Act, 1890, 
inserted the following clause : — 

§ 25 : " It shall not be lawful to erect a new building 
on any ground which has been filled up with any matter 
impregnated with faecal, animal, or vegetable matter, or 
excavation or otherwise, or shall have been rendered or 
have become innocuous. 

" Every person who does or causes, or wilfully permits 

B 



18 SANITARY GONSTBUGTION IN BUILDING. 

to be done, any act in contravention of this section, shall 
for every such offence be liable to a penalty not exceeding 
£5, and a daily penalty not exceeding 4:0s." 

The wording, it will be noticed, is rather broader than 
in the bye-law, as it gives a builder the opportunity to 
*' render " it " innocuous," if it has not already " become " 
so. It also provides for a cumulative penalty, calculated 
to deter a builder from erecting dwelling-houses on foul 
land. 

It must be noted that not every town and district has 
its regulations based on the m.b.l. ; and consequently it 
may happen that the m.b.l. No. 10 is of no help to the sanitary- 
inspector. It must also be noted that the p.h.a. Amendment 
Act, 1890, is a permissive Act, and must be adopted before 
§ 25 is available for application. 

For any district which is so much behind the times in 
sanitation, it will be the first duty of the sanitary officials 
to draw up a new code of regulations. 

The Medical Officer of Health of one of our large county 
boroughs has prepared a Report, accompanied by a map, 
showing the whole of the land in the borough which has 
been filled up with foul or even doubtful material. When- 
ever any plans for new buildings upon any of these areas 
are deposited with the Corporation for approval, a careful 
examination of the land is made, a trial hole to the full depth 
of the filled material is excavated, and if the material is 
innocuous, the medical officer gives a certificate to that 
effect. If the foul matter has not become innocuous, the 
Corporation withhold their consent until the builder has 
removed it or rendered it innocuous. 

This plan is well worthy of adoption, as it will save much 
friction by preventing any dispute whilst the houses are 
actually in course of erection. In many of the smaller towns 
and districts the examination of deposited plans is part of 
the sanitary inspector's work ; and if he is well acquainted 
with the geology of the district, and knows the position of 
the clay land and the tipped land, he will be able to enforce 
the precepts and laws of sanitation much better than one 
who knows nothing of the science. 

In considering the sanitary suitability of the various 
subsoils, the two chief points to be inquired into are (a) the 



SOILS, SUBSOILS, AND SITES. 19 

quantity and nature of the air in the interstices of the soil, 
and (6) the quantity, quality, and movements of the water 
in the interstices of the soil. 

The quantity and nature of the air occupying the inter- 
stices of the soil will be considered first. "The hardest 
rocks alone are perfectly free from air ; the greater number 
even of dense rocks, and all the softer rocks, and the loose 
soil covering them, contain air. The amount is in loose 
sands often 40 or 50 per cent. ; in soft sandstones, 20 to 
40 per cent. 

" The amount of air in rocks can be roughly estimated, 
in the case of rather loose rocks, by seeing how much water 
a given bulk will absorb, which can be done by measuring 
the water before and after the weighed or measured rock 
is inserted in it, or by weighing the rock after immersion. 
But a more exact plan is to weigh a piece of the rock when 
dry ; to thoroughly satutate it with water, and weigh again, 
so as to obtain the weight of the water it has taken up. The 
specific gra^dty of the rock having been previously deter- 
mined . . . the calculation is — 

wt.. of water taken up x 100 ^ i. . ,» 

—r — 5 — ^ -, = percentage of air. 

wt. of dry rock -r- spec. g. 

(Parkes, "Hygiene." Ch. VIII. Sec. 1, Sub-sec. 1.) 

Or when the soil is loose, dry it at 212° F., and powder 
it, but without crushing it very much ; carefully take the 
c^be contents, then pour upon it a measured quantity of 
water until a thin layer is seen above it. The calculation is — - 

Amount of water used x 100 » . 

— r^^ P — 7 r— J — -1 - = percentage of air. 

cubic centimetres of dry sou ^ ^ 

" The subterranean atmosphere thus existing in loose 
soils and rocks is in continual movement, especially when 
the soils»are dry ; the chief causes of movement are the diurnal 
changes of heat in the soil and the fall of rain, which must 
rapidly displace the air from the superficial layers, and at 
a later date, by raising the level of the ground water, will 
slowly throw out large quantities of air from the soil. 

" Local conditions must also influence the movement ; 
a house artificially warmed must continually be fed with 
air from the ground below, and doubtless this air may be 
drawn from great depths." 



20 SANITARY CONSTRUCTION IN BUILDING, 

Now as regards the nature of this ground air, Dr. Parkes 
says : " It is mostly very rich in carbonic acid. . . Occa- 
sionally it contains carburetted hydrogen, and in moist 
soils, when the water contains siflphates, a little sulphuretted 
hydrogen may be found." 

Dr. Ransome says (" Soils and Sites," p. 8) : " The ground 
air is not exactly like the air of the atmosphere around us. 
It is true that it is a mixture of the same gases — oxygen, 
nitrogen, and carbonic acid ; but in atmospheric air there 
are usually only 4: parts per 10,000 of carbonic acid, and 
20 per cent, by volume of oxygen. In ground air the oxygen 
at a depth of a few yards diminishes in some cases to 15 
per cent., and the carbonic acid may rise to as much as 8 
per cent. — 200 times more than in atmospheric air. This 
tendency to substitute carbonic acid for oxygen increases 
the deeper we get into the ground. 

" Professor Pettenkofer, to whom we owe much of our 
knowledge of underground physics, found that in the neigh- 
bourhood of Munich the carbonic acid varied from 1*58 per 
1,000 volumes at a depth of 5 ft., to 18*38 at a depth of 13 ft. 
At this last-mentioned depth, then, the air would be quite 
irrespirable, and it would at once extinguish a light. It was 
at Dresden that Fleck found the large proportion of 80 parts 
of this gas per 1,000." 

* Dr. Ransome then proceeds to urge the importance of 
keeping this ground air out of the house, and the danger 
of breathing such impure air. What, then, must be the 
nature of the emanations from the refuse sometimes used 
to fill up low-lying land ? Imagine the consequence of breath- 
ing the effluvia arising from the rotting offal of a fish market 
or a vegetable market, together with an admixture of ashpit 
refuse and excreta ! 

The L.G.B., acting on the advice of their inspectors, have 
drawn up a m.b.l. specially intended to shut out this ground 
air. The means suggested also serve the purpose of shutting 
out underground waters to a great extent. The bye-law is : — 

M.B.L. No. 11 : " Every person who shall erect a new 
domestic building shall cause the whole ground surface 
within the external walls of such building to be properly 
asphalted or covered with a layer of good cement concrete, 
at least 6 in. thick, or 4 in. thick if properly grouted." 



SOILS, SUBSOILS, AND SITKS. 21 

The annotator in Messrs. Knight's edition makes the 
following Note : " The sanitary advantages of this clause are 
considerable. Residence on a damp subsoil as the foundation 
for a house has long been known to favour the prevalence 
of disease, such as pulmonary consumption, hence regulations 
to prevent dampness rising from the soil beneath a house 
into the interior of the house are obviously desirable. All 
soils and rocks are more or less pervious, and this is especially 
the case with gravel, sand, and chalk, which are popularly 
deemed to afford the best subsoils for dwelling-houses. In- 
deed, chalk will hold some 16 per cent, of its weight in water ; 
in a similar way large volumes of ground air are held in 
its pores, and both this and the moisture, when drawn up into 
a house by the influence of temperature, or as the effect of 
a direct suction resulting from fires, etc., tend to injurious 
results. The injurious influence of ground air in dwellings, 
especially in thickly populated places, is becoming more 
and more recognised. Where the foundations are laid in 
some specially dry formation, serious and fatal disease has 
followed on the soakage of filth from a leaky drain on neigh- 
bouring premises, or otherwise, into the soil beneath a house. 
This source of danger, which has been found especially grave 
in the case of pervious gravels and fissured rocks, is obviated 
by the adoption of the model clause. It is to be remem- 
bered that the extra cost of adopting the precaution pre- 
scribed in this clause cannot add greatly to the cost of a 
house, seeing that a cubic yard of concrete costs perhaps 
ftom 10s. to 15s., and, at 6 in. thick, will cover an area of 
54 sq. ft. As it is an additional safeguaTd to require the 
Tipper surface of the concrete to be grouted and floated over 
to a smooth surface with cement, a reduced thickness is 
permissible where this is done. ... It may further be 
pointed out that in many cases — as in halls, lobbies, and 
certain kitchen offices — the concrete may form the finished 
flooring, and thus save any additional cost for other kinds 
of flooring." 

Ground air is very probably instrumental in assisting 
the growth of dry rot. Very little is known as yet as to 
the origin of this fungus, but it is certain that a closed-in 
space to which ground air has access is extremely favour- 
able to its development, whilst a space freely ventilated 



22 8ANITABY CONSTRUCTION IN BUILDING. 

and from wliich ground air is excluded is very seldom 
attacked. 

Mr. Keith D. Young mentions a "case which shows the 
importance of covering sites with a layer of concrete : " In 
a cottage situated about twenty or thirty yards from the 
shaft of a disused coal mine, certain cases of illness had 
occurred, the symptoms of which pointed to a very danger- 
ous gas called carbon monoxide. The disused shaft referred 
to communicated with a mine in work. To facilitate ventil- 
ation in the mine which was in work, a fire had been lit and 
suspended in the shaft of the disused mine, and this furnace 
had set fire to the coal in the latter mine.. The cottage in 
question is the end of a row, and has a cellar which has an 
opening into the outer air. This opening was usually covered 
over by a piece of board which effectually excluded the air 
from the cellar. For several weeks previous to the occurrence 
of the illness in question, the surface of the ground had been 
frozen hard and covered with snow. What, therefore, hap- 
pened was this : the gas generated in the mine, finding no 
way of exit through the frozen and snow -covered surface 
of the ground, had penetrated the subsoil until it reached 
the ground under the house, where it foimd a ready exit. 
In the adjoining house the cellar opening was covered with 
a board which did not fit well, and consequently allowed some 
of the gas to escape. In this cottage the inmates suffered 
from the same illness, but in a much less severe form." 
(" Sanitary Building Construction," Journal of the Sanitary 
Institute, Vol. xv.. Part 1, p. 39.) 

Dr. Ransome quotes another instance, as narrated by 
Professor Pettenkofer, which shows how far ground air 
" may travel when sucked in by the in-draught caused by 
warm and ascending air inside a house. 

" In December, 1859, the Chaplain of St. Ulrich's Church, 
at Augsburg, was suddenly seized with a serious illness, 
the nature and cause of which were inexplicable. The Sisters 
of Mercy who nursed him were one after another seized 
with the same symptoms — pain and congestion of the head, 
fainting, etc. The symptoms always became aggravated 
when the weather got colder. After some time, no improve- 
ment having appeared, a friend who came to see him one 
day exclaimed, on entering the room : ' There is an escape 



SOILS, SUBSOILS, AND SITES, 23 

of gas ! ' This was denied by all connected with the house, 
and declared by the doctor to be immaterial, as the patient 
was now pronounced to be undoubtedly suffering from fever. 
At length, however, a person was sent for from the gas office, 
and he at once said there was an escape, but confessed him- 
self unable to discover its source. The patient, however, 
acted on the hint, and having left the house in spite of the 
doctor, recovered in a few days. No sooner was he gone 
and the windows of his apartment thrown open, and the 
fire let out, than his next neighbour was attacked by the 
very same symptoms. He too, recovered, at once by a rapid 
flight from the house. 

" It was impossible to examine the underground pipes 
at the time, as the ground was frozen hard. However, at 
the end of six days this was done, and an escape was dis- 
covered in the main pipe which ran in the centre of the street 
some 20 ft. off, the gas escaping in such quantities as to burn 
briskly when lighted. 

" The coldness of the weather had necessitated larger 
fires in the house, and the increased heat developed a current 
of air from the ground into the house, the gas being sucked 
up with it. When the patient had left the house, his room 
was allowed to cool, and the current of air and gas was thus 
diverted to the apartments of his neighbour." (" Soils and 
Sites," p. 10.) 

It will, of course, be readily perceived that if in these 
two cases the carbon monoxide and the coal gas could travel 
long distances underground, and that if it may be drawn into 
houses by the suction of the warm air, any other air or gas, 
whether pure or deleterious, that the ground may contain 
may with equal facility be thus conveyed into the interior 
of the house. 

There is this peculiarity also to notice — foul water travel- 
ling a distance underground is filtered and purified, but 
foul gases travelling a considerable distance through ground 
are not. 

The sanitary inspector has not only to prevent houses 
being erected on insanitary land, but after the houses are 
erected he must prevent the earth becoming fouled and 
polluted with house refuse, or the leakage of drains and midden 
privies. It will be seen presently how this ground air is 



24 SANITARY CONSTRUCTION IN BUILDING, 

forced into houses by the movements of the subsoil water, 
and how necessary it is that the concrete bed should be 
absolutely impervious. 

The second point in the inquiry as to the sanitary suit- 
ability of a site concerns the quantity, quality, and move- 
ments of the water present in the subsoils. When air as 
well as water is present in the soil, the soil is merely moist, 
the quantity varying with the power of the soil to absorb 
and retain water, and with the supply of water to the soil, 
either from above as rain or from below by capillary attraction. 

Dr. Parkes says that " a loose sand may hold 2 gal. of 
water in 1 cub. ft., and ordinary sandstone may hold 1 gal. 
Chalk takes 13 to 17 per cent. ; clay, if not very dense, 20 ; 
ordinary garden soil (humus), as much as 40 to 60, and retains 
it strongly. . . . The driest granite and marbles will 
contain from "4 to 4 per cent, of water, or about a pint in 
each cubic yard." 

Dr. Ransome says : " Except in very hot climates, or 
occasionally in very hot summers in this country, all soil 
is more or less damp, and generally, even in the hottest 
weather, we have only to dig a few inches into the groimd 
before we find a certain degree of dampness." (" Soils and 
Sites," p. 11.) 

But at a certain depth below the surface — a depth that 
varies with different soils and strata — ^we find that the inter- 
stices of the soil are filled with water, air no longer being 
present ; the ground is saturated, so that " except in so 
far as its particles are separated by solid portions of soil, 
there is a continuous sheet of water." (Dr. Parkes.) Any 
space made by the spade speedily fills with the water flowing 
into it from the porous soil around. This water is called 
the ground water, or the subsoil water, or the " ream " 
water. 

This subterranean sheet of water is at very different 
depths below the surface in different soils ; sometimes it 
is only two or three feet from the surface, in other cases as 
many hundreds. In a marsh it rises quite to the surface. 
The level depends, says Dr. Parkes, " on the compactness 
or permeability of the soil, the ease or difficulty of outflow, 
and the existence or not of an impermeable stratum near 
or far from the surface. The underground sheet of water 



SOILS, SUBSOILS, AND SITES. 25 

is not necessarily horizontal, and in some places it may be 
brought nearer to the surface than others by peculiarities 
of ground. The water is in constant movement, in most 
cases flowing towards the nearest watercourses or the sea, 
at a rate which has not yet been perfectly determined. . . . 
The level of the ground water is constantly changing. It 
rises or falls more or less rapidly, and at different rates in 
different places ; in some cases its movement is only a few 
inches either way, but in most cases the limits between its 
highest and lowest levels in the year are several feet. 

" The causes of change in the level of the ground water 
are the rainfall, pressure of water from rivers or the sea, 
and alterations in the outfall, either increased obstructions 
or the reverse. The effect of the rainfall is sometimes only 
traceable weeks or even 'months after the fall, and occa- 
sionally, as in plains at the foot of hills, the level of the ground 
water may be raised by rainfalls occurring at long distances. 
The pressure of water in the Rhine has been shown to affect 
the water in a well 1,670 ft. away." 

The consequences of living on a damp soil hardly come 
within the purview of a sanitary inspector ; they are. rather 
the concern of the medical officer. There is, however, strong 
evidence that it predisposes to rheumatism, neuralgia, catarrh, 
phthisis, ague, and other affections ; that where the sub- 
soil water level is very near the surface, malarious fevers 
are rife ; and that where the level alters considerably and 
at frequent intervals, thus forcing the ground air to evolve 
from the surface, paroxysmal fevers occur just as regularly 
as the water level alters. Where the ream level is below the 
basement of the house, a layer of concrete is all that is 
necessary ; but where the level is higher than the basement 
floor, something should be done to lower it. 

The L.G.B. on this point have issued the following as a 
Model Bye-law : — 

M.B.L. No. 59 : " Every person who shall erect a new 
building shall cause the subsoil of the site of such building 
to be effectually drained by means of suitable earthenware 
field-pipes, properly laid to a suitable outfall, wherever the 
dampness of the site renders such a precaution necessary. 

" He shall not lay any such pipe in such a manner or 
in such a position as to communicate directly with any sewer 



26 SANITARY CONSTRVCTION IN BUILDING. 

or cesspool, or with any drain constructed or adapt«d to be 
used for conveying sewage, but shall provide a suitable trap, 
with a ventilating opening, at a point in the line of the aub- 
Boil drain as near as may be practicable to such trap." (See 
Figs. 1 and 2.) 

Upon this the annotator comments as follows ; — 

" The necessity of draining the subsoil beneath buildings 



I 



/^y 






Fig. 2. 
Figs. 1 ann 2.— Subaoil Drainage, Section and Plati. ' 

has already been referred to (Clause No. 11). Owing to the 
pervious character of the drain necessary for this purpose, 
it is imperative that sewer air should not be allowed to gain 
entrance to it and from it inUi the surrounding soil. Hence 
the conditions specified in the second paragraph. Where 
the system of sewerage in operation is that known as the 
' separate system ' — that is, where such part of the rainfall 
as is free from serious pollution is excluded from the sewers 



SOILS, SUBSOILS. AND SITES. 27 

and conveyed separately to some watercourse or other place, 
a suitable outiall for this pipe-drain may easily be obtained 
by connecting it with the rainwater drain. Under other 
circumstances it is desirable that the outfall should be either 
direct into the open air, or, where it must be conveyed to 
the sewer, that the nearest approach to this should be obtained 
in the manner shown (Figs. 1 and 2). Where, however, a 
trap is used to preclude the entry of sewer air or cesspool 
air into the pipe-drain, arrangements should be made to 
ensure the maintenance, even in the driest seasons, of a 
sufficiency of water in the trap. Thus, a fresh-water tap 
may be fixed for this purpose near the ventilating opening." 



Ground LeyJ 




L^^feJcTafcr Uv«l 



Fig. 3. — Position of Subaail Fij;. i. — Open-Pointed Fipe- 

Pipt'drain. drain, Burrounded with 

A down-pipe may be with advantage connected to this 
opening. 

The L.G.B. have in this m.b.l. touched nearly every point 
of the one method suggested. The closeness of the drains 
to each other will be determined by the porosity of the soil. 
The pipes should be of unglazed pottery and butt-jointed, 
not socketed. It is important, however, that they should 
be truly laid to an even gradient, or tliey merely become 
underground cisterns, aggravating the evil they were intended 
to cure. They should be surrounded or covered with a 
layer of gravel, 6 in. thick, to facilitate the percolation of 
water. {See Figs '•^ and 4.) The discharge from these drains 
may, if in the country, be led into a watercourse ; or, if 
in a town, they should be led into a trapped disconnecting 
chamber or gully, discharging thence into the main drain 
or public sewer. (See Figs. 5 and 6.) 



28 SANITARY CONSTRUCTION IN BUILDING. 

These subsoil drains should never be used for the con- 
veyance of sewage, and never used for the ventilation of 
the sewers. It is imperative that they themselves should be 
ventilated ; the upper ends should be in communication 
with the open air, so that if by any mischance the trap at 
the outlet becomes unsealed, the sewer gas may have an 
opportunity to escape without contaminating the subsoil. 





Fig. 5. Fig. 6. 

Fij^s. 5 and 6. — Methods of Trapping Drain Outlets. 

The intercepting chamber at the outlet should have the 
character of a ventilated manhole sufficiently large to admit 
of thorough inspection. 

If the sanitary inspector has sufficient knowledge of 



<3rrou¥iJ^ 




f {SBm 



Fig. 7. — Obstruction of Subsoil Water. 



geology, he may possibly discover much cheaper means of 
lowering the subsoil water than by laying an expensive 
network of deep drains. He may find an embankment of 
clay, which acts as an underground dam, as shown at Fig. 
7, and prevents the flow of the subsoil water ; a ditch cut 
through this and filled with gravel, brickbats, or other per- 
vious material, may be an effectual, permanent, and in- 
expensive remedy. He may find that the water runs down 



BOILS, SUBSOILS, AND SITES. 2!l 

a hill towards the house, aod that a Bimilar ditch dug farther 
up the liill nmy divert the water (see Figs. 8 and 9). He 
may find that the house is very unwisely placed iu the centre 
of a depression, like a teacup in a saucer (see Fig. 10), so 
that there is apparently no flow of underground water in 




t>^i« 



if 



Fig. 8. Fig. 9. 

i. 8 and 9.— Diverting Down-hill Flow of Water, Saotion and Plan. 



any direction, and he may discover that immediately below 
the impervious strata there is a highly pervious subsoil ; 
he then digs an absorption well, and the ream water being 
led into this, is absorbed by the pervious strata. {G. D. 




Fig. 10.— Obatructed Rain 



Porous Strata. 



. Dr. 



Dempsey, "[Drainage of Districts and Lands" 
Ransome, "Soils and Sites," p. 4.) 

Other methods may suggest themselves, among which 
is the raising of the subsoil water to a sufiicient height by 
mechanical means, there being many appliances for this 
purpose. Wind-pumps, steam-pumps, compressed air-pumps, 



30 8ANITABY CONSTRUCTION IN BUILDING, 



Shone's pneumatic ejector, Adams' sewage and water liit, 
among many others, may be mentioned. 

A method of avoiding subsoil air and water is to build 
the house on a series of arches, as shown in Fig. 11, so that 
it may be clear above the surface of the ground. Yet another 
method is to lay a bed of concrete, make the excavation 
larger each way than the house, and construct concrete 
retaining walls (see Fig. 12). 




Fig. 11.- 



-Foundation laid on Arches to avoid Subsoil Air 
and Water. 



From what has already been said, it will be seen that 
from a hygienic point of view the m.b.l. No. 11 is an ex- 
ceedingly wise provision. The jerry-builder may grumble 
at the cost ; the average person may be blindly indifferent ; 




t 










Fig. 12. — Foundation laid on Concrete Bed to avoid Subsoil 

Air and Water. 

but the motto of the sanitarian is, " The health of the people 
is the highest law." 

In towns where the " concrete bed " bye -law does not 
exi^, there ought, at all events, to be regulations furthering 
the same object. Where a house has cellars, they should 
be paved with impervious material — either with concrete 
or with flags jointed with cement. Where the house is not 
cellared, and has boarded floors, there should be a space of 
at least 18 in. below the joists, and this space should be 



SOILS, SUBSOILS, AKD SITES. 31 

ventilated by means of two or more large air-grids {9 in. 
by C in.) on opposite sides ; and, wherever practicable, an 
extra flue should be carried up in the chimney breast and con- 
nected to this space, bo as to iorm an exhaust ventilation abaft 
(see Fig, 13). The floor boards should be rebated or grooved 
"and tongued, so as to prevent the passage of foul air and 
also cold air from the air grids. The l.g.b. have the following 
M.B.L. on this point : 

M.B.L. No. 55 : " Every person who shall erect a new 
domestic building shall so construct every room which shall 
be situated in the lowest storey of such building, and shall 



Fig. 13. — Ventilation of Space under Bottom Floor. 

be provided with a boarded floor, that there shall be, for 
the purpose of ventilation, between the under side of every 
joist on which such floor may be laid, and the upper surface 
of the asphalt or concrete with which, in pursuance of the 
bye-law in that behalf, the ground surface or site of such 
building may be covered, a clear space of 3 in. at the least 
in every part, and he shall cause such space to be thoroughly 
ventilated by means of suitable and sufficient air-bricks, or 
by some other effectual method. Provided that the foregoing 
requirement shall not apply in the case of a room provided 
with a solid floor composed of boards, planks, or wood blocks, 
laid or bedded directly upon concrete or other similar dry 
and impervious foundation." 

There are two other m.b.l. (Nos. 12 and 13) which will 



32 SANITARY CONSTRUCTION IN BUILDING. 

be of very great use to those towns adopting them. They 
give the Local Authority power to prohibit the erection 
of dwelling-houses, upon excavated sites, low -lying land, or 
land liable to be flooded, until the site has been filled up 
to a certain level alcove ordnance datum* with clean material, 
so as to form a " stable and healthy substratum " for the 
foundation of such building. 

The following is the text of these bye-laws : — 
M.B.L. No. 12 : "In every case where the intended site 
of a new building may have been or may have formed part 
of a clay pit, or where, by reason of excavation and the 
removal of earth, gravel, stones, or other materials from 
such site, the whole or any part of the surface thereof may 
be at such a depth below the level of the surface of the ground 
immediately surrounding and adjoining such site as may 
render the elevation of the whole or part of the existing 
surface of such site necessary for the prevention of damp 
in any part of any building to be erected thereon : A person 
shall not construct any foundation of a new building 
upon such site or upon such part thereof as, for the purpose 
aforesaid, may require elevation, unless and until there shall 
have been properly deposited thereon a layer or layers of 
sound and suitable material sufficient to elevate such site 
or such part thereof to an adequate height, and to form a 
stable and healthy substratum for such foundation." 

M.B.L. No. 13 : " In every case where the intended site 
of a new building may be [within an area bounded by] [at 
a height less than ft., above ordnance datum] (here 

insert, aUerncUivdy, the height below which, or a description of 
the boundaries of the area to which, the following requirement 
is to apply), a person shall not construct any foundation of 
such building unless and until there shall have been properly 
deposited upon the site a layer or layers of sound and suit- 
able material sufficient to elevate such site to a height at 
least ft. above the ordnance datum." 

♦ The ordnance datum is an imaginary horizontal plane extending 
over the whole country at the same height as the mean sea level at 
Liverpool. This was fixed by the Surveyors of the Ordnance Depart- 
ment, and the levels of districts are marked on the ordnance maps as 
being so many feet above the ordnance datum or above the meaii sea 
level at Liverpool. 



SOILS, SUBSOILS, AND SITES. 33 

Coining to questions about the healthiness of a site itself, 
it is found that the structure and composition of the under- 
lying geological strata are of less importance than is generally 
supposed. Examining the data on this head given by Dr. 
Parkes, and confirmed by other sanitarians, it appears that 
there are very few positively unhealthy grounds, provided 
they are natural and not artificially laid down, and are not 
polluted from some external source. Much depends, how- 
ever, on the method of using the site, the position of the 
house, etc. 

Granitic, metamorphic, and trap rocks, as well as the 
slates, are generally healthy, as these usually slope con- 
siderably, so that water runs off readily, and they are very 
impermeable ; but when they have begun to disintegrate 
or decompose, they pass into a sort of loam, occasionally 
become permeated with fungus, and are supposed to be 
unhealthy. 

Limestones and hard calcareous rocks generally form 
healthy sites, when not overlaid by a marsh, and not water- 
logged. A word of caution is necessary on this latter point : 
the ground-water level in such rocks as the limestones varies 
with the rainfall of the district ; and what at one period 
of the year is an apparently dry site, may become water- 
logged for months together. 

The sandstones, sands, and gravel are always healthy, 
except when low-lying and water-logged. Clays, loam, dense 
marls, and alluvial soils, generally damp in their nature, 
are to be regarded with suspicion, and should be carefully 
and discreetly dealt with in the ways already suggested. 
Made soils have been fully discussed (pp. 15-17). Probably 
the most healthy site for building purposes is on a dry gravel 
soil of moderate thickness and in an elevated position. 

Captain Galton, in his work on " Healthy Dwellings," 
gives instances showing the sanitary importance of the situ- 
ation of a house. One of these has reference to the outbreak 
of fever among soldiers in the Crimea. Fig. 14 shows the 
slope of the ground falhng towards the plain of Balaclava. 
The foundations are rock below and above, traversed by a 
belt of clay and shale. The 79th Highlanders were placed 
on the clay, and as the material was soft, their huts were 
placed on terraces cut out of the hillside, and were thus 
c 



Si 



SANITARY GONST&VCnON IN BVILDING. 



embedded in the ground ; and the Soore, conseqnentl]'', were 
always damp. There was no roof ventilation. This regiment 
had half the men down with fever. The 4:2nd Highlandera 
were placed on the lock, and as it was hard, they did not 
cut into the rock, but preferred building theii> huts on pro- 



)J^ Ho^vtf. 




Fig. 15. — Improved Construction and Position of Lower HuLi. 

jecting terraces, so that they were quite dry, and air circu- 
lated freely round. This regiment did not sufier from fever. 
The huts on the clay were subsequently altered as shown 
at Fig. 15, BO as to allow free circulation of air. Drainage 
and roof ventilation were provided as shown, and fever no 
longer prevailed. 



SOILS, SUBSOILS, AND SITES. 35 

The story emphasises the importance of making a geological 
examination of a site, wherever the inspector is called in to 
inquire into the cause of any mysterious outbreak of disease. 
The whole evidence before us shows the necessity in many 
cases ; and it also shows that a healthy site may be only 
the space of a few feet from an unhealthy site (see also Fig. 16). 
On the other hand, the inspector must beware of becoming 
a crank on this one point of his examination, or he may 
blame the soil for illnesses with which it has nothing what- 
ever to do. 



Heatrty Siit 











Fig. 16. — Healthy and Unhealthy Sites for Houses. 

Messrs. Miers & Crosskey, in their valuable Httle work, 
" The Soil in Relation to Health," cite a case in which the 
soil was hastily blamed for illness that was really attributable 
to defective sanitary engineering : "A family who for many 
years had lived in a town situated upon a deep bed of gravel, 
moved into a house built on the clay. On taking up their 
new residence, nearly all the family suffered from sore throats 
of a septic nature, which were at once attributed to the 
' horrid damp clay.' It was found, however, on investigation, 
that the ventilating shaft to the soil-pipe opened just under- 
neath one of the best bedroom windows, and the waste-pipe 
to the bath was untrapped, and joined the soil-pipe. When 
these and other defects were remedied, there was no further 
trouble from sore throats." 



36 



CHAPTER III. 

MATERIALS OF CONSTRUCTION. 

The materials to be used in the structure of walls are referred 
to in Bye -law No. 14, which reads as follows : — 

M.B.L. No. 14 : " Every person who shall erect a new 
building shall, except in such cases as are hereinafter specified, 
cause the external and party walls to be constructed of good 
bricks, stone, or other hard and .incombustible materials, 
properly bonded and solidly put together : (i) With good 
mortar compounded of good lime and clean sharp sand, 
or other suitable material ; or (ii) with good cement ; or 
(iii) with good cement mixed with clean sharp sand." 

The materials, then, of which walls may be constructed 
are " bricks, stone, or other hard and incombustible 
materials " ; the latter may be taken to include terra-cotta, 
tiles, concrete, and other artificial stones. The healthiness 
of these materials depends upon their non-absorbent qualities. 
They must not be absorbent of moisture in the form of rain, 
or the dampness will be transmitted through to the interior ; 
they must not be porous, or the external air will penetrate 
either by its own force or owing to the suction of the chimney. 

A good brick should be hard, so that it may be able to 
stand the knocking about before, and the pressure to which 
it will be subjected after, it is built into the structure ; should 
be well burnt, so that it may withstand damp, which is 
terribly destructive to ill-burnt bricks ; should be truly 
square and regular in shape, with clean sharp arrises ; 
when struck should give out a clear metallic ringing sound ; 
and when broken, should break clear, without falling to 
pieces as it were. The size of bricks varies in different parts 
of the country. In London users prefer them 8| in. by 4 J in. 
by 2| in. thick ; in Lancashire, 9 in. by 4J in. by 3 in. ; and 
some makers send them out even thicker than 3 In. Their 
weight is about 7| lb. each, or 110 lb. to the cubic foot. 
Machine-made bricks are heavier. 



MATERIALS OF CONSTRUCTION, 37 

As regards porosity, in 1868 the Manchester Society of 
Architects tested experimentally a large number of different 
kinds of bricks, taken indiscriminately from buildings then 
in progress and from brickyards. The results of these ex- 
periments are thus summarised : " Bricks should not absorb 
when saturated above 20 per cent, of their bulk of water, 
and should absorb it reluctantly, and part with it with facility 
at ordinary temperatures." Now the wall of a cottage 16 ft. 
long, 8 ft. high, and 9 in. thick will contain 96 cub. ft. ; and 
supposing the wall to absorb 20 per cent, of its bulk, as stated 
above, it would hold in its pores 19 cub. ft., or nearly 120 
gal. of water ! Hence the necessity for adopting non-porous 
materials for walls, and the stipulation for damp-proof courses, 
and the advisability of cavity walls. 

Terra-cotta and tiles may be considered as bricks in 
other forms, and of a less porous nature. Terra-cotta has 
a glazed surface, which to some extent throws ofE the water ; 
tiles are nailed to the surface of the wall, hence there is a^ 
slight cavity which prevents the transmission of absorbed water. 
^ For ordinary buildings stone is only used in a " stone " 
country ; and then the local stone is used without reference 
to its porosity or fitness in other respects. The stone being 
cheap in its unworked state, walls are built thicker than 
the minimum necessary for hygienic construction, as it is 
cheaper to build^ thick walls than to expend time and labour 
in cutting the stones to the smaller size. More care should 
be taken in bonding the stones together than in a brick 
wall ; numerous " through " stones should be provided in 
rubble work, and the small spaces between the largest stones 
should be filled with pieces of stone as large as can be placed 
there, for the wall is to be of stone, not of mortar. Great 
care also should be taken that the stone, of which most of 
that used for building purposes is stratified or laminated 
like the leaves of a book, shall be placed on what is called 
its natural bed — that is, with the strata or leaves lying hori- 
zontally, as it was formed in the quarry. If 'this is not done 
the action of the air in most cases will cause the laminae 
or strata to separate or fall away. Instances of this may be 
seen in buildings where certain stones have been, as it were, 
eaten away for some inches in depth. Stones should be 
marked on the top side at the quarry as a guide. 



38 SANITARY CONSTRUCTION IN BUILDING, 

There are very few parts of the country where there is 
not an ample supply of clay suitable for brickmaking, or of 
stone ; hence in not many places is concrete building any- 
thing but an experiment. Cases may arise, however, where 
a building has to be erected in concrete, in which case the 
following points, among others, will need attention : (a) 
The Portland cement should be of the best quality in all 
respects; {b) The aggregate should consist of hard gravel, 
broken stone, broken bricks, burnt clay ballast, or other 
suitable material, small enough to pass through a 2-in. ring ; 
the sand should be clean and sharp, (c) The proportions 
should be 1 part cement, 2 parts sand, 4 parts aggregate. 
(d) Proper gauge-boxes should be provided for measuring 
the various materials ; no guesswork or rule-of-thumb should 
be allowed on any pretext, (e) The work should be carried 
up in layers of equal height. (/) Provided the foregoing 
conditions are duly observed, the walls need not be built 
any thicker than if brickwork were used. Of course, proper 
templates and framework should be carefully fixed to con- 
fine the concrete until it has set. This will need consider- 
able care and ingenuity. 

The second portion of the bye-law now claims attention. 
It will be seen that while good lime is specified, there is 
nothing to show what is meant by good lime, nor how it is 
to be distinguished from bad lime ; good mortar is also 
required, but the constituents of good mortar are not specified. 
In a Note on the subject, however, the following modifications 
are suggested by the annotator : — 

" (a) With good mortar, compounded of freshly burned 
lime and clean, sharp sand or grit, without earthy matter, 
in the proportion of 1 of lime to 3 of sand or grit ; or, 

" (b) With good Portland cement or other good cement 
of equal quality mixed with clean, sharp sand or grit in the 
proportion of 1 of cement to 4 of sand or grit : 

" Provided that in either case hard burnt ballast or 
broken brick may be substituted for sand or grit if clean 
and not mixed with any old mortar, and provided that such 
hard ballast or broken brick be properly mixed with lime 
or cement in a mortar-mill." 

Where this modification is adopted, bye-law No. 15 
should be similarly altered. 



MATERIALS OF CONSTRUCTION. 39 

The sand should be clean sharp river or pit sand ; if 
sea sand is used, it should be well washed to remove the 
saltness, otherwise the mortar will not set, or, if it does, 
it will be hygrometrical — that is, in damp weather it will 
become wet, owing to the salt in it, and remain so until the 
atmosphere dries, thus acting as a perpetual barometer. 
The sand should be clean, as any admixture of clay, soil, 
slime, or other impurity will kill much of the lime, and the 
m.ortar will disintegrate or become rotten within a few weeks 
or months after setting, even if it sets at all. A simple test 
is to rub some of the sand in the palm of the hand. If it 
is not clean it will leave a stain, the depth of the stain indicating 
the amount of impurity. The sand should also be sharp 
or gritty ; seen through a microscope each grain should 
be all angles, like a piece of crystaUised sugar-candy ^ and 
not rounded like lumps of gum arabic. 

There are many available substitutes for sand, but they 
must all be crushed under rollers in a mill until they are 
similar in size to grains of sand. Among them may be noted 
crushed stone, burnt clay or ballast (but it must be thoroughly 
burnt), smithy ashes, furnace slag and scoriae, and anything 
of similar nature which is gritty, hard, clean, and used with 
discretion. Other substitutes have been used by the jerry- 
builder, such as road sweepings, garden soil, ashpit refuse, 
etc. ; the sanitary inspector will have to keep his eyes open 
on this point, especially in those towns where the bye-law 
is indefinite. 

Limes are divisible into three classes — (1) rich or pure 
or fat lime ; (2) poor or impure or meagre lime ; and (3) 
hydraulic lime. Rich lime is burnt from stones that consist 
almost entirely of carbonate of lime (calcium carbonate) ; 
other substances may be present to the extent of 10 per 
cent. The calcium carbonate or limestone is burnt to expel 
the water and carbonic acid gas it contains, the product 
being calcium oxide ; when the calcium oxide is slaked 
by addition of water it becomes calcium hydrate ; when 
calcium hydrate is mixed with sand — that is, made into 
mortar — and the mortar placed in position between bricks, 
etc., it absorbs carbonic acid gas from the atmosphere, and 
once more becomes calcium carbonate or limestone. This 
rich lime is unsuitable for mortar for external walls, and 



40 SANITAEY GONSTRXIGTION IN BUILDING. 

should not be used in exposed places, as it is soluble in water, 
and will not set in damp situations. It is, however, valuable 
for internal plastering. Poor lime has all the disadvantages 
of rich lime, with others added ; it is rich lime ve^ much 
adulterated, and should never be used. 

Hydraulic lime will set in damp situations without drying 
(hence its name), and becomes harder with age. The most 
important hydraulic limes owe their pexjuliar quality to a 
certain proportion of clay being mixed with or forming part 
of the raw stone. After burning, the lumps are broken 
small, and slaked with a minimum quantity of water. The 
most useful hydraulic limes are those obtained from blue 
lias limestone, which is found in many parts of England. 

There are several important provisions in m.b.l. No. 14. 
They read as follows : — 

" (a) That such person may construct any external wall 
of such building as a hollow wall, if such wall be constructed 
in accordance with the following rules : (i) The inner and 
outer parts of the wall shall be separated by a cavity which 
shall throughout be of a width not exceeding 2 J in., and 
shall be properly drained and ventilated, (ii) The inner and 
outer parts of the wall shall be securely tied together with 
suitable bonding ties of adequate strength, formed of galvan- 
ised iron, of iron tarred and sanded, or of glazed stoneware. 
Such ties shall be placed at distances apart not exceeding 
3 ft. horizontally and 18 in. vertically, (iii) The thickness 
of each part of the wall shall throughout be not less than 
44 in. (iv) The aggregate thickness of the two parts, ex- 
cluding the width of the cavity, shall throughout be not 
less than the minimum thickness prescribed by the bye-law 
in that behalf for an external wall of the same height and 
length, and belonging to the same class of building as that 
to which the hollow wall belongs, (v) All woodwork which 
may be intended to form the head of a door frame or window 
frame, or lintel, or other similar structure, and may be in- 
serted in the wall so as to project into or extend across the 
intervening cavity, shall be covered throughout on the 
upper side thereof with a layer of sheet lead, or other suit- 
able material impervious to moisture, in such a manner 
as effectually to protect such woodwork from any moisture 
that may enter the cavity. 



MATERIALS OF CONS THUG TION. 41 

" (h) That where a new building intended for use as a 
dwelling-house shall be distant not less than 15 ft. from 
any adjoining building not being in the same curtilage, the 
person erecting such new building may construct its external 
walls of timber- framing, subject to compliance with the 
following conditions, that is to say : — (i) The timber- framing 
shall be properly put together, and the spaces between the 
timbers shall be filled in completely with brickwork or other 
solid and incombustible material, (ii) A thickness of at 
least 4 J in. of brickwork or other solid and incombustible 
material shall be placed at the back of every portion of 
timber. 

*' (c) That where a new building forms or is intended 
to form part of a block of new buildings which shall be in- 
tended for use as dwelling-houses, and shall not exceed 
three in number, and each of which shall be distant not 
less than 15 ft. from any adjoining building not being in 
the same curtilage, and not forming part of the same block, 
the person erecting such new building may construct its 
external walls of timber-framing, subject to compliance with 
the following conditions, that is to say : — (i) The several 
buildings shall be separated by party walls, each of which 
shall be constructed in accordance with the requirements 
of the bye-laws in that behalf, and shall project at least 
1 in. in front of any timber-framing in any adjoining external 
wall, (ii) The timber-framing shall be properly put together, 
and the spaces between the timbers shall be filled in com- 
pletely with brickwork or other solid and incombustible 
material, (iii) A thickness of at least 4 J in. of brickwork 
or other solid and incombustible material shall be placed 
at the back of every portion of timber. 

" (d) That where a new building which comprises two or 
more storeys forms, or is intended to form, part of a block 
of new buildings which shall be intended for use as dwelling- 
houses, and shall not exceed three in number, and each of 
which shall be distant not less than 15 ft. from any other 
building, not being in the same curtilage and not forming 
part of the same block, the person erecting such new build- 
ing may construct the external walls of the topmost storey, 
or if the building comprises more than two storeys, of the 
topmost two storeys, of timber- framing covered with tiles. 



42 SANITARY CONSTRUCTION IN BUILDING. 

subject to compliance with the following conditions, that 
is to say — (i) The timber-framing shall be properly put 
together, with sufficient braces, ties, plates, and sills, (ii) 
So much of any external wall as is below that portion which 





■ fe^B 



Fig. 17. 

Fig. 17.— Jennings' Old Tat tern 
Bonding Brick. 



Fig. 18. 

Fig. 18.— Jennings' 1891 
Bonding Brick. 



may be of timber-framing covered with tiles shall be con- 
structed of the same thickness, and in other respects subject 
to the same conditions, as would be applicable if the wall 
had been constructed throughout its whole height of good 





Fig. 19. 

Fig. 19, — Doulton's Bonding 
Brick. 



Fig. 20. 

Fig. 20. — Wrought-iron Bonding 
Tie. 



bricks, stone, or other hard and incombustible materials, 
(iii) Every party wall in any such block of buildings shall 
be carried out at least to the external face of any timber- 
framing in any adjoining external return wall. 





Fig. 21. Fig. 22. 

Figs. 21, and 22. — Wrought-iron Bonding Ties. 

One of the best bonding ties for cavities is a Jennings 
bonding brick. The old pattern (Fig. 17) was defective, 
in that it only fitted courses of a certain gauge, and had 
to be tilted one way or the other if the course varied from 
the thickness of the bonding brick. In the 1891 pattern 



MATERIALS OF C0N8TBU0TI0K 



43 



(Fig. 18) this defect has been remedied. Equally good is 
Messrs. Doulton's bonding brick (Fig. 19). Wrought-iron 
cramps of various shapes may be used (see Figs. 20, 21, 
and 22). The m.b.l. allows the thickness of each half-wall 
to be 4 J in. There is a general consensus of opinion that 
one of the portions of the wall should be 9 in. thick, though 
there is not the same agreement as to whether the thick 
portion or the thin portion should be placed on the outside. 
As a rule, it is better for the 9-in. portion to be outside and 
the 4J-in. portion inside. The stipulation for a sheet of 
lead on the upper surface of any beam will be better under- 
stood by reference to Fig. 23. 

In building a cavity wall the bricklayer should lay a 




Fig. 23. — Section of Lead-covered Beam. 



lath along the bottom of the cavity to catch the droppings 
of mortar ; and when he reaches the level of the bonding 
brick, he should carefully draw up the lath, and lay it on 
top of the bonding brick until the next is reached. A cavity, 
in addition to resisting damp, tends to keep the house cooler 
in summer and warmer in winter, the air in the cavity acting 
like a cushion to prevent the transmission of heat. Many 
objections have been made to the construction of cavities : 
they form runs for vermin, they transmit noises from one 
part of the building to another, rattling noises are heard 
from bits of mortar dropping, and if sewer gas finds its way 
into the cavity it may be transmitted all over the house, 
and filter through all the walls. 

With a view of obviating these annoyances and nuisances, 
many sanitary engineers construct the cavity only about 
J in. in width, and pour in melted asphalt. This being done 
every six courses, the wall becomes a solid homogeneous 
mass — damp-proof and much stronger than an ordinary 
wall (see Figs. 24 and 25). 



44 SANITARY CONSTRUCTION IN BUILDING, 

The next three m.b.l. explain themselves. No. 15 requires 
that cross-walls shall be of the same good materials as the 
external walls ; No. 16 stipulates that all walls shall be 
built true and plumb ; and No. 17 insists that walls joining 
one another shall be bonded together. 

M.B.L. No. 15 : " Every person who shall erect a new 
building shall construct every cross-wall, which, in pur- 
suance of the bye-law in that behalf, may, as a return wall, 
be deemed a means of determining the length of any ex- 
ternal wall or party-wall of such building, of good bricks, 
stone, or other hard and incombustible materials properly 
bonded and solidly put together : — (i) With good mortar 





Fig. 24. Fig. 25. 

FigB. 24 and 26.— Hollow-built Walls Filled with Asphalt. 

compounded of good lime and clean sharp sand, or other 
suitable material ; or (ii) with good cement ; or (iii) with 
good cement mixed with clean sharp sand." 

M.B.L. No. 16 : "A person who shall erect a new building 
shall not construct any wall of such building so that any 
part of such wall, not being a part properly corbelled out 
or supported, or a projection intended solely for the purposes 
of architectural ornament, shall overhang any part beneath 
it." 

M.B.L. No. 17 : " Every person who shall erect a new 
building shall cause every wall of such building which may 
be built at an angle with another wall to be properly bonded 
therewith." 



CHAPTER IV. 

EO0T1NQ8, FOUNDATIONS, AND DAMP-PROOF COURSES. 

The next m.b.l, deals with the footings. The object of 
footings is, as the name impbes, to give the wall something 
to stand npon ; and it may be remarked that footings are 
absolutely necessary wherever the ground is of a softer 
nature than the material of which the wall itself is com- 
posed. The u.B.L. on this portion of the subject is as 
follows : — 

M.B.L. No. 18 : " Every person who shall erect a new 



building shall construct every wall of such building so as 
to rest upon proper footings, or upon a sufficient bressummer. 

" He shall cause the projection at the widest part of 
the footings (if any) of every wall, on each side of such wall, 
to be at least equal to one half of the thickness of such wall 
at its base, unless an adjoining wall interferes, in which case 
the projection may be omitted where that wall adjoins. 

" He shall also cause the diminution of the footings to 
be in regular offsets, or in one offset at the top of the foot- 
ings, and he shall cause the height from the bottom of the 
footings to the base of the wall to be at least equal to two- 
thirds of the thickness of the wall at its base." 

Sketches of the footings of the walls of ordinary thickness, 



46 SAm-TABY 00N8TRUGTI0N IN BUILDINO. 

drawa as described in this regulation, are given in PJgs. 

26, 27, and 28. Prom the dimensions shown on these figures 
it will be seen that the t«tal breadth of the footings is twice 
the thickness of the wall. Where there is an adjacent wall 
the footiEgs on that side are not necessary (see Fig, 29). 
Footinga have been sometimes formed solid — that iB,,witli- 



Fig. 28,— Footings foe 18-iii. Fig. 29,— Footing b on one Side 

Wall, of Wall only. 

out the aet-offs of 2J in. each, as shown in Pig. 30 ; and from 
this fact it is argued that when the ground is harder than 
the wall, footings are unnecessary. 

When a building has been constructed with inadequate 



Fig. 30.— Footinga without Fig. ai.— Footings added to Exiistinf- 

Set-offB. Work. 

footings, and it becomes necessary to increase their width, 
this can be done by carefully excavating in short lengths, 
and constructing wider footings in cement mortar, properly 
bonded into the existing work (see Fig. 31) ; each side of 
the wall being done at difierent times. 

It often happens that the soil upon which a building ia 



POOTIJSrOS, FOUNDATIONS. ETC. *7 

to be erected is too soft to receive the footings, a circumstance 
for which the next bye-law makes the following provision: — 

M.B.L. No. 19 : " Every person who shall erect a new 
building shall cause the footings (if any) of every wall of 
such building to rest on the solid ground, or upon a sufficient 
thickness oE good concrete, or upon some solid and sufficient 
substructure, as a foundation." 

Foundations are divided into classes, according to the 
nature of the ground and the weight of the building. Among 
soft grounds are classed peat, quicksand, loam, surface soil 
or humus, and others of a similar nature. Among the medium 
grounds are the damp sands, loose gravels, wet clays, shales, 
sham rocks. The hard grounds comprise the rocks, dense 
dry clays, and close dry gravels. The method of preparing 



Fig. 33.-Pil£ 



foundations upon these various materials depends chiefly 
upon the weight of the proposed building. 

Heavy building on soft ground presents the most difficult 
problem, and the subject is so large that it is here only possible 
to indicate the more usual methods of treatment. When it 
is necessary to erect a heavy building upon soft ground, 
jnoie solid ground underneath must by some means be 
reached ; and there are two courses open— either to excavate 
the full depth, or to drive piles. 

If the soft ground is of but moderate depth— say less than 
20 ft. — trenches may be cut under the walls down to the 
solid, and filled up with concrete. If the soft ground is much 
less than 20 ft., it may be excavated entirely, and either 
used as a cellar or filled up with concrete or hard, dry 
material. 

If the soft ground is more than 20 ft. in depth, piles 



■48 SANITARY CONSTRUCTION IN BUILDING. 

muBt be used. The term piles is here employed in the very 
broadest sense, and may be taken as including pillars of 
timber, iron, steel, concrete, or brickwork. An ordinary 
timber or iron pile needs no description. It must be sufficiently 



Fifr. 3*.— Brick Pillar oa Cutting Ring. 

long to reach the solid ground (timber piles may be obtained 
up to 70 ft. in length), and the piles must be sufficiently 
numerous to carry the weight. Timber piles should be cut 
off at the ground-water level. Across the tops should be 




Fig. 35. --Concrete Fonndatlui 



laid crossheads either of timber (Fig. 32)_ or of steel {Fig. 
33) ; and upon these a bed of concrete covering the whole 
site should be laid. 

Concrete or brick pillars may either be excavated for 
and built solid ; or may be built on a cutting ring (Fig. ;J4) 



FOOTINGS, FOUNDATIONS, ETC. *9 

and foEced down, the material being taken from the inside, 
and the apace afterwards filled with concrete. The former 
method will serve when there is little or no water to contend 
with ; the latter when it is cheaper to use a grab than to 
pump. A third couise is possible. In Chicago there aie 
portions of the town where a solid bottom cannot be reached, 
the subsoil growing softer as excavation goes deeper. In 
such cases very little excavating is done, but an exceedingly 
broad foundation, of concrete bound together and inter- 
laced with steel girders, is formed, and this practically float* 
upon the liquid foundation. On this the buildings are erected, 
some of them being more than ten storeys high. 



Pig. S6.— Wall Foandation Formed by FlagatoneB. 

In the case of light buildings on soft ground it ia not 
necessary to find a soHd bottom ; indeed, it the uppermost 
stratum is fairly firm, while the underneath strata are soft, 
it is better not to excavate more than is absolutely necessary. 

A broad platform of concrete (Fig. 35), 6 ft. or 9 ft. wide 
and 2 ft. or 3 ft. thick— the thickness varying according to 
the softness of the Boil^will be quite ample ; or, if the soil 
is fairly hard, two thicknesses of strong rough flags (Fig. 36) 
will suffice, with the proviso that the weight of the building 
should be approximately equal throughout. If one portion 
of the building consists of three storeys, and another portion 
of only one storey, there will be unequal settlement, and 
large cracks will become manifest. Unless the building be 
of equally distributed weight throughout, the concrete founda 
tion must be sufficiently large to act as a beam, and to bear 
the unequal load without breaking. 



50 SANITARY CONSTRUCTION JN BUILDING. 

It is possible to spend an enormous amount of money 
on foundations in bad ground — sometimes more than the 
whole value of the building itself. On the other hand, by 
unwise parsimony in preparing the foundations, it is quite 
possible to ruin a costly building for ever. 

Very great care is necessary in determining how much 
or how little foundation should be provided for heavy build- 
ings on medium ground. There is always a natural tempta- 
tion to consider the ground good enough. With damp sands 
and wet clays it might be thought sufficient to lay a broad 
foundation of concrete. Here, however, there is great 
danger that water abstracted from underneath, thereby allow- 
ing shrinkage of the subsoil, will lead to equal or unequal 
settlement. An adjacent railway cutting or well may lead 
to this abstraction of water, and the consequences would 
be disastrous. The shales are also dangerous, owing to the 
tendency to slide under pressure ; the cutting of a sewer 
in the street, or even for the building in course of erection, 
or an excavation next door may lead to this. No decision 
should be arrived at, even when the excavation has been 
got out as far as the footing level, without two or more deep 
trial holes sunk several feet farther. 

Even when a bed of rock has been reached it is not safe 
to use that until a boring has been driven down some dis- 
tance,; for in a multitude of cases, and especially in alluvial 
soils, the rock may be only 2 in. or 3 in. thick, overlying a 
bed of sand or quicksand, while the real rock is some feet 
deeper. Mr. John Holden, f.r.i.b.a., found a case of this 
sort in the foundations of the Grosvenor Hotel (Holden : 
" Foundations and Materials," p. 56). In another case a 
trial hole was dug for the purposes of ascertaining strata 
and preparing plans and quantities. The trial hole was con- 
tinued until rock was reached. After the contract had been 
signed the excavation was got out, and it was found that 
the bed of rock, on which it was intended to erect a lofty 
chimney, was only 2 in. thick ; the excavation had to be 
continued 10 ft. or 11 ft. deeper, and the extra cost was 
between £200 and £300. As before remarked, a lot of money 
may be squandered from want of wisdom, whilst undue parsi- 
mony may be ruinous from want of discretion. 

Light buildings on medium ground, and light and heavy 



FOOTINGS, FOUNDATIONS, ETC. 51 

buildings on hard ground, need no special description as 
to their foundations. A little wisdom combined with sufficient 
discretion will indicate the right sort of foundation. 

On the subject of damp-proof courses the m.b.l. of the 
L.G.B. is very strict, but not more strict than the importance 
of the matter demands, considering the porous nature of 
brickwork and its power of absorbing and transmitting water 
by capillary attraction. The bye-law reads thus : — 

M.B.L. No. 20 : " Every person who shall erect a new 
public building or 'a new domestic building shall cause every 
wall of such building to have a proper damp-proof course 
of sheet-lead, asphalt, or slates laid in cement, or of other 
not less durable material impervious to moisture, beneath 
the level of the lowest floor, and at a height of not less than 
6 in. above the surface of the ground adjoining such wall. 
Provided always that where any part of a floor of the lowest 
storey of such building, not being a cellar adapted and in- 
tended to be used for storage purposes only, shall be intended 
to be below the level of the surface of the ground immediately 
adjoining the exterior of such storey, and so that the ground 
will be in contact with the exterior of any wall, he shall 
cause such storey, or such part thereof as will be so in con- 
tact, to be constructed with walls impervious to moisture 
or with hollow walls, constructed in accordance with the 
requirements of the bye-law in that behalf, and extending 
from the base of such walls to a height of 6 in. at least above 
the surface of the ground immetliately adjoining the exterior 
of such storey. He shall also cause a proper damp-proof 
course of sheet-lead, asphalt, or slates laid in cement, or of 
other not less durable material impervious to moisture, to 
be inserted in every such wall at the base of such wall, and 
likewise at a height of 6 in. above the surface of the ground 
immediately adjoining." 

It will be seen that the l.g.b. appear to have considered 
all possible contingencies — namely, floor above the external 
ground, at the level of the ground, and when the floor is 
below the external ground level. 

The illustrations to the m.b.l. No. 20 are reproduced by 
permission of Messrs. Knight and Co. Fig. 37 shows the 
position of the damp-proof course when the floor is above 
the external ground ; Fig. 38 when the floor is at the level 



52 SANITARY CONSTRUCTION IN BUILDING. 

of the external ground ; and Fig. 39 when the floor is below 
the external ground level, d p signifles damp-proof course ; 
a, ground ; fl, floor ; j, joist; c, concrete ; cav., cavity ; w, 
wall-plate, and v, flag. 



As to the material to be used, the beat, though the most 
costly, ia that first mentioned, namely, sheet lead. This 
should be of the thickness known as " 4-lb. lead " — that ia. 



Fig. 39. — Damp.proof ConrM when Floor is below drooud Level. 

weighing 4 lb. to each superficial square loot. Lead has 
the following advantages : — (o) It is very effectual ; (6) it 
is not squeezed out by pressure ; (c) it gives to the inequalities 
of the bricks ; (d) it is not injured by unequal settlement. 



fOOTIItOS, Jb^OUNBAtlOltS, ETC. S3 

Staffordshire blue bricks set in portland cement form a 
good damp-proof course. These bricks are practically non- 
porous, and, if the joints are well filled with cement, the 
course is quite effectual. Mr. John Taylorj in 1859, deviled 
a course formed of two vitrified tileSj channel-shaped, and 
of length equal to the thickness of the wall (Fig. 40)* His 
later pattern is a single tile with grooves on the outside 
faces (see Fig. 41). Other tiles on similar principles are 




Figr. 40.— Taylor's Original Fig. 41.— Taylor's Improved 

Damp-proof Course. Damp-proof Course Tile. 

manufactured by Messrs. Doulton (Fig. 42), Broomhall 
(Fig. 43), and others. 

Slates set in portland cement are also used as a damp- 
proof course. To be effectual the laying must be done with 
the greatest care ; otherwise, by the unequal pressure, the 
slates are sure to crack and break. There should be two 
courses of •slate, with cement below, between, and above, 
and the slates should break joint. 

The material generally used for a damp-proof course is 
asphalt, its quality depending very much upon the amount 





Fig. 42.— Doulton's Damp- Fir, 43. — Broomhall's Damp- 

proof Course Tile. proof Course Tile. 

of money the owner is spending upon the building. The 
best natural asphalt, the seyssel, or limmer rock (an excellent 
material), is at one end of the line ; at the other end is the 
jerry -builder's asphalt, formed of coal-tar, pitch, and sand. 
Between these two are many grades of asphalt damp-proof 
courses, the misfortune being the absence of a legal definition 
as to the real substance intended under the designation 
" asphalt." To meet the difficulties that may arise in this 



54 SANITARY CONSTBUGTION IN BUILDING. 

respect, the clause has been modified in some districts as 
folfows : 

"Every person who ■shall erect a new building shall 
cause every wall of snch building to have a proper damp- 
couise of sheet lead, mineral asphalt, or slates laid in cement, 
or of other suitable hard-setting and durable material, not 
being tarred felt, and impervious to moisture, beneath the 
level of the lowcat floor, and at a height of not less than 
6 in, above the surface of the ground adjoining such wall." 

Another method of keeping out the dampness of the 
external ground is by a coating of asphalt on the outer face 
of the brickwork. This ia adopted as an ordinary practice 




b'ig. 4,->. FiK. 46. 

of Dry Areas for Keeping out Damp. 

by sanitary engineers. A Local Authority has, however, 
no means of enforcing it in its district. The p.h.a., 1875, 
gives power to make bye-laws " with respect to the structure 
of walls, foundations, etc." ; but a coat of asphalt on the 
outer face of a wall is not an integral part of the structure 
of the wall ; and therefore no bye-law can be made to enforce 
such a desirable protection against damp. 

Sanitary engineers also attain the same end by constructing 
external cavities or dry areas. There are many ways of 
constructing these, three examples being shown at Figs. 44, 
45, and 46, where g l is the ground level and d the drain. 

In view of the foregoing provisions, all made with the 
view of keeping out damp, it may be useful to bear in mind 
a simple test for finding out whether a room or a house is 
too damp to be healthy. The method is recommended by 



FOOTINGS, FOUNDATIONS, ETC. 55 

Dr. Paolo Mantezza, and although rough-and-ready and 
somewhat superficial, is easy to carry out, and accurate 
enough for all practical purposes. "It is based on the 
property which certain bodies have of absorbing the water 
contained in the air — as lime, for instance. Take 500 grammes 
of lime, newly burned, not slaked or pulverised ; place it 
on a plate in the room to be examined for twenty -four hours, 
with the doors and windows closed ; at the end of this time 
weigh it, and if the weight has not increased more than a 
gramme, the room may be declared inhabitable. If the 
weight has increased 5 grammes or more the room cannot 
be inhabited without danger. The proper degree of hygro- 
metry oscillates between 1 gramme and 5 grammes more 
or less for inhabited places. This test, which is not mathe- 
matical, of course, can be applied suitably always to rooms 
of ordinary dimensions. It would not be suitable for very 
large or very small rooms." 

The law is not very precise, though quite clear, with 
regard to the action of the sanitary inspector in the case of 
damp houses. § 91 of the p.h.a., 1875, says : " . . . Any 
premises in such a state as to be a nuisance or injurious to 
health . . . shall be deemed to be nuisances liable to 
be dealt with summarily in manner provided by this Act." 
Here are two separate grounds on which a damp house may 
be dealt with : First, is it in such a condition as to be a 
nuisance ? Secondly, is it in such a condition .as to be in- 
jurious to health ? The Act, however, does not give a 
definition to the term nuisance, and this has provided much 
work for the lawyers. Mr. Justice Blackstone says : " Nuis- 
ance, nocumentum, or annoyance, signifies anything which 
worketh hurt, inconvenience, or damage. Aiid nuisances 
are of two kinds — ^public or common nuisances which affect 
the public and are an annoyance to all the King's subjects, 
for which reason we must refer them to the class of public 
wrongs or crimes and misdemeanors ; and private nuisances, 
which are the objects of our present consideration and may 
be defined as anything done to the hurt or annoyance of 
the lands, tenements, or hereditaments of another." 

Lord Mansfield, c.j., says : "To constitute a nuisance 
it is enough that the matter complained of renders the enjoy- 
ment of life and property uncomfortable." Seeing that there 



56 SANITARY G0N8TRVCTI0N IM BUILDING. 

is no definition of a nuisance by law, many magistrates will 
not order the nuisance to be abated unless it is both a nuisance 
and injurious to health. The sanitary inspector will there- 
fore have to be guided in his action by the opinion of the 
medical officer of health and the view of the town clerk 
or other legal adviser on the whole question. 

The sanitary inspector will often be asked to advise a 
cure for damp walls, as, unfortunately, there are damp walls 
in existence in spite of m.b.l. and other sanitary regulations. 
The first step to a cure is to find out the cause, and, having 
done this, to apply a suitable remedy ; and these remedies 
should generally be on the following lines : If the damp 
springs from the surrounding earth, a dry area (see Figs. 44, 
45, and 46) or external cavity should be constructed, or the 
wall should be asphalted, and an open- joint drain laid ; if 
from the absence of a damp- course, a course of bricks should 
be cut out and a damp-proof course inserted. If the mortar 
absorbs the moisture and transmits it to the inside, the 
outside should be pointed with cement or other impervious 
mortar. If the bricks are at fault, the whole outer face 
of the wall should be painted or tarred, or covered with 
slates. Or a 4i-in. wall may be built up on the inside of 
the room, leaving a ^-in. cavity, which is then to be filled 
with asphalt. On no account should the inner face of the 
wall be covered with sheet lead or other impervious lining. 
It is an absolute necessity that the walls should absorb 
the moisture generated in the room ; otherwise, the moisture 
will condense on the surface of the wall, run down in un- 
sightly streams, and form a sticky slime on it. 



CHAPTER V. 

STABILITY OF WALLS. 

There ia great riek of permanent injury to health in a house 
whore the walls are collapsing from weakness, and bye-laws 
have been framed dealing with the stabihty of walla, m.b.l. 
No. 21 indicates how measurements shall be taken : — 

H.B.L. No. 21 : " For the purposes of the bye-laws with 




Fig. 47.^Iiitemal wall not exceeding 3» (t. hieh and 30 ft. la length. 
Fig. Vi. — Internal wall not esceedinst 23 ft. high and exceeding 30 ft. 
in length. Fig. 49.— External wall not exceeding 2a fL high and 
exceeding 30 ft. iu length. ¥ig, 50.— Internal wall 25 ft. ti> 30 ft. 
high not exoeeding 35 ft. in length. Fi?. Sl.^Extemal wall 25 ft. 
to 30 ft. hi(!h not exceeding 35 ft. in length. Fig. f)2.— External 
wall 26 ft. to 30 ft. high and exceeding 3:j ft. in length. Fig. 53.— 
Internal wall 25 ft. to :W ft. high and exceeding 35 ft in length. 

respect to the structure of walls of new buildings, the measure- 
ment of height of storeys and of height and length of walls 
shall be determined by the following rules : — (i) The height 
of a storey shall be measured in the case of the lowest storey 
of a building from the base of the wall, and in the case of 
any other storey from the level of the upper surface of the 
floor of the storey up to the level of the upper surface of 



58 SANITARY GONSTBVOTION IN BUILDING. 

the floor of the storey next above it ; or if there be no Buch 
Btorey, then up to the highest part of the containing walla, 
(ii) The height of a wall shall be measured from the base 
to the highest part of the wall, or in the case of a wall com- 
prising a gable, to half the height of the gable : provided 
that in the case of a party wall comprising a gable the measure- 
' ment shall be from the base of the wall to the level of the 



Fig. B4. Vig. .io. Pig. 66. Fig. S7, 
Fig. 64— Internal wall 3U ft, to 40 ft. high not exceeding 3.t ft. in 
len^tfa. Fig. GE.— External wall SO ft. lo 40 ft. high not exceeding 
35 ft. in length. Fig. .56.— External wall SO ft. to 40 ft. high and 
exceeding 36 ft. in length. Fig. ST.— Internal wall 30 ft. to 40 ft. 
high and exceeding S6 ft. in length. 

base of the gable, (iii) Walls shall be deemed to be divided 
into distinct lengths by return walls. The length of a wall 
shall be measured from the centre of one return wall to the 
centre of another, provided that the return walls are external 
walls, party walls, or cross walla, of the thickness prescribed 
by the bye-laws, and are bonded into the walla so deemed 
to be divided. A wall shall not, for the purpose of this 
rule, be deemed a cross wall unless it is carried up to the 
top of the wall so deemed to be divided (or in the case of 



STABILITY OF WALLS. 59 

a gable wall to the level of the base of the gable), and unless 
in each storey the aggregate extent of the vertical faces 
or elevations of all the recesses and that of all the openings 
therein, taken together, shall not exceed one-half of the 





Fiff E8 Fig 69 FiR. 60. Fig. 61. Fif, 62. Fig. «3. 
Fift. 58.— InterDal wall 40 fL to 50 ft. liigh not exoeeding SO ft. in 
length. Fig. 6U.— External wall 40 ft. to 60 ft. high not exceeding 
30 ft. in length. Fig. 60.— External wall 40 ft. to 50 (t. high not 
cxceediDiT *5 ft. in length. Fig. 61— Internal wall 40 ft. to 60 ft, 
high not eiceedEng 45 ft. in length. Fig. 62.— Internal wall 40 ft. 
to 50 ft. hiith and exceeding 45 ft. in length. Fig. 63.— External 
wall 40 ft. lo 50 ft. hL<;h and exceeding 46 ft. in length. 

whole extent of the vertical face or elevation of the wall 
in such storey." 

M.B.L, No. 22 then proceeds to specify particularly the 
various thicknesses of wall for various heights and lengths. In 
the following illustrations the horizontal measurements have 
been reproduced to twice the scale of the vertical measurements, 
and in each case the letter a indicates an external wall. 



eO SJNITARY CONSTRUCTION IN BlTlLtHNO. 

M.B.L. No. 22 : " Every pereon who shall erect a new 
domestic building shall constract every ettemal wall and 
every party wall of such building m accordance with the 
following rules, and in every case the thickness prescribed 




Fig. 64. Fig.Cj Fig,(i6 Fig.G7. 
Fig. 64.— Internal wall 50 ft. to fiO ft. higli not exceeding 45 ft. in 
length. Fig. 65.— External wall 50 ft. to 60 ft. high not exooedinir 
45 ft. in length. Fig, 66,~Intornal wall 50 ft. to 60 ft, high and 
exceeding 15 ft. in lenirth. Fig, 67.— External wall 50 ft. to 60 ft. 
high and exceeding 45 ft. in length, 

shall be the nkinimum thickness of which any such wall 
may be constructed, and the several rules shall apply only 
to walls built of good bricks not less than 9 in. long, or of 
suitable stone or other blocks of hard and incombustible 



STABILITY OF WALLS. 



subataQce, the beds or courses being horizontal, (a) Where 
the wall does not exceed 25 ft. in height, ite thickness shall 




Fig. 69. Fig, 69. Fig. 70. 1 
Fig. 68.— Internal wall 60 ft. to 70 ft. high e 
length: Fig. 69. — External nail 60 ft, t« TO ft. high not exceeding 
45 ft. in length. Fig. TO.— Exterpal wall 60 ft. to 70 ft. high and 
eiceeding 45 ft in length. Fig. 71.— Internal wall 60 ft. to 70 ft. 
high and exceeding 15 ft. in length. 

be as iollows : — If the wall does not exceed 30 ft. in length, 
it shall be 9 in. thick for ita whole height (Fig. 47). If the 



SANITARY CONSTRUCTION IN BUILDING. 



§r 



Fig. 72. Fig. 73. F^. 74. Fig. 75. 
Fig. 72.— Internal wall 70 ft. to 80 ft. higli and exceeding 45 ft. ia 
length. Fig. 73.— External wall 70 tt. to 80 ft, high and eiceeding 
46 ft. in length. Jfig. 74— Estemal wall 70 ft. to 80 ft. high not 
exceeding 45 ft. in length. Fijr. 7&.— Internal wall 70 ft. to 80 ft. 
liigli not exceeding 15 ft. in length. 



Fig. 76. Fig. 77. Fig. 78, Pig. 79. 

JfiiT. 76.— Intornal wail 80 ft, to 90 ft. high not esceeding 45 ft. in 
length. FiK. 77.— Exteriml wall 80 ft. to 90 ft. high not exceeding 
45 ft. in length. Fi(f. 78— External wall 80 ft. to 90 ft. high and 
exceeding 45 ft. in lei^th. Fig. 79.— Internal wall 80 ft. to 90 ft. 
high and exceeding 45 ft. in length. 



t2i) lia liiJ ^ 

-■-^ -^ . -■- 



Fig. 80, Fig. 81. Fig. 82. Fig. 83. 

Fig. 80.— Internal wall 90 ft. to 100 ft. hiph not exceeding iB ft. in 
length. Fi(r. 81.— External wall 90 ft. to 100 ft. Mgb not exceeding 
45 ft. in length. Fig. 82.— Eitcrnal wall 90 ft to 100 ft. hiRh and 
eiceeding 45 ft. in lensth. Fig. SS.— Internal wall 90 ft. to 100 ft. 
high and exceeding 4.5 ft. in length. 



STABILITY OF WALLS. '65 

wall exceeds 30 ft. in length, it shall be 13J in. thick from 
the base for the height of the lowest storey, and 9 in. thick 
for the rest of its height (Fig. 48). (6) Where the wall 
exceeds 25 ft. but does not exceed 30 ft. in height, its thick- 
ness shall be as follows : — If the wall does not exceed 35 ft. 
in length, it shall be 13|^ in. thick from the base for the height 
of one storey, and 9 in. thick for the rest of its height (Fig. 
50). If the wall exceeds 35 ft. in length, it shall be 13 j in. 
thick from the base for the height of two storeys, and 9 in. 
thick for the rest of its height (Fig. 53). (c) Where the wall 
exceeds 30 ft. but does not exceed 40 ft. in height, its thickness 
shall be as follows : — If the wall does not exceed 35 ft. in 
length, it shall be 13 J in. thick from the base for the height of 
two storeys, and 9 in. thick for the rest of its height (Fig. 54) ; 
if the wall exceeds 35 ft. in length, it shall be 18 in. thick 
from the base for the height of one storey, then 13 J in. thick 
for the height of two storeys, and 9 in. thick for the rest 
of its height (Fig. 57). (d) Where the wall exceeds 40 ft. 
but does not exceed 50 ft. in height, its thickness shall be 
as follows : — If the wall does not exceed 30 ft. in length, 
it shall be 18 in. thick from the base for the height of one 
storey, then 13J in. thick for the height of two storeys, and 
then 9 in. for the rest of its height (Fig. 58) ; if the wall exceeds 
30 ft. but does not exceed 45 ft. in length, it shall be 18 in. 
thick from the base for the height of two storeys, and 13J in. 
thick for the rest of its height (Fig. 61) ; if the wall exceeds 
45 ft. in length, it shall be 22 in. thick from the base for 
the height of one storey, then 18 in. thick for the height 
of the next storey, and then 13J in. thick for the rest of its 
height (Fig. 62). (e) Where the wall exceeds 50 ft. but does 
not exceed 60 ft. in height, its thickness shall be as follows : — * 
If the wall does not exceed 45 ft. in length, it shall be 18 in. 
thick from the base for the height of two storeys and 13^ 
in. thick for the rest of its height (Fig. 64) ; if the wall exceeds 
45 ft. in length, it shall be 22 in. thick from the base for the 
height of one storey, then 18 in. thick for the height of the 
next two storeys, and then 13J in. thick for the rest of its 
height (Fig. 66). (/) Where the wall exceeds 60 feet but does 
not exceed 70 ft. in height, its thickness shall be as follows : — 
If the wall does not exceed 45 ft. in length, it shall be 22 in. 
thick from the base for the height of one storey, then 18 in. 

E 



66 SANITARY CONSTRUCTION IN BUILDING. 

thick for the height of the next two storeys, and then 13 J 
in. thick for the rest of its height (Fig. 68) ; if the wall exceeds 
45 ft. in length, it shall be increased in thickness in each 
of the storeys below the uppermost two storeys by 4:J in. 
(subject to the provision hereinafter contained respecting 
distribution in piers), (g) Where the wall exceeds 70 ft. 
but does not exceed 80 ft. in height, its thickness shall be 
as follows : — If the wall does not exceed 45 ft. in length, 
it shall be 22 in. thick from the base for the height of one 
storey, then 18 in. thick for the height of the next three 
storeys, and then 13 J in. thick for the rest of its height (Fig. 
75) ; if the wall exceeds 45 ft. in length, it shall be increased 
in thickness in each of the storeys below the uppermost two 
storeys by 4J in. (subject to the provision hereinafter con- 
tained respecting distribution in piers), (h) Where the wall 
exceeds 80 ft. but does not exceed 90 ft. in height, its thick- 
ness shall be as follows : — If the wall does not exceed 45 ft. in 
length, it shall be 26 in. thick from the base for the height of 
one storey, then 22 in. thick for the height of the next storey, 
then 18 in. thick for the height of the next three storeys, 
and then 13J in. thick for the rest of its height (Fig. 76) ; 
if the wall exceeds 45 ft. in length, it shall be increased in 
thickness in each of the storeys below the uppermost two 
storeys by 4 J in. (subject to the provision hereinafter con- 
tained respecting distribution in piers), (i) Where the wall 
exceeds 90 ft. but does not exceed 100 ft. in height, its thick- 
ness shall be as follows : — If the wall does not exceed 45 ft. 
in length, it shall be 26 in. thick from the base for the height 
of one storey, then 22 in. thick for the height of the next 
two storeys, then 18 in. thick for the height of the next 
three storeys, and then 13J in. thick for the rest of its height 
(Fig. 80) ; if the wall exceeds 45 ft. in length, it shall be 
increased in thickness in each of the storeys below the 
uppermost two storeys by 4 J in. (subject to the pr?) vision 
hereinafter contained respecting distribution of piers). 

" Provided that notwithstanding anything contained in 
the foregoing rules (a) to (i) inclusive — (i) Every external 
and party wall of any storey which measured from the level 
of the floor of that storey to the level of the floor of the storey 
next above it, if any, exceeds 11 ft. in height shall be not 
less than 13J in. in thickness ; and (ii) if any storey exceeds 



STABILITY OF WALLS. 67 

in height sixteen times the thickness hereinbefore prescribed 
for its walls, the thickness of each external ^nd party wall 
throughout that storey shall be increased to one-sixteenth part 
of the height of the storey, and the thickness of each external 
wall and of each party wall below that storey shall be propor- 
tionately increased (subject to the provision hereinafter con- 
tained respecting distribution in piers). 

" Provided further that where in accordance with the 
reqiiirements x>f this bye-law an increase of thickness is 
required in the case of a wall exceeding 60 ft. in height and 
45 ft. in length, or in the case of a storey exceeding in height 
sixteen times the thickness prescribed for its walls or in 
the case of a wall below that storey, the increased thick- 
ness may be confined to piers properly distributed, of which 
the collected widths amount to one -fourth part of the length of 
the wall. The width of the piers may nevertheless be reduced 
if the projection is proportionately increased, the horizontal 
sectional area not being diminished ; but the projection of 
any such pier shall in no case exceed one-third of its width." 

M.B.L. No. 23 need not be reproduced, as it merely con- 
sists of similar regulations for the walls of public buildings 
and buildings of the warehouse class. The m.b.l. then 
proceed to define the thickness of cross walls, which are 
generally to be two -thirds the thickness of an external wall 
of the same height and length, but in no case less than 9 in. 

M.B.L. No. 24 : " Every person who shall erect a new 
building shall construct, in accordance with the following 
rules, every cross wall which, in pursuance of the bye-law 
in that behalf, may, as a return wall, be deemed a means 
of determining the length of any external wall or party 
wall of such building ; and in every case the thickness pre- 
scribed shall be the minimum thickness of which any such 
wall may be constructed ; and the several rules shall apply 
only to walls built of good l>ricks not less than 9 in. long, 
or of suitable stone or other blocks of hard and incombustible 
substance, the beds or courses being horizontal. The thick- 
ness of every such cross wall shall be at least two-thirds of 
the thickness prescribed by the bye-law in that behalf for 
an external wall or party wall of the same height and length, 
and belonging to the same class of building as that to which 
such crosg wall belongs, but shall in no case be less than 



68 SANITARY CONSTRUCTION JN BUILDING, 

9 in. ; but if such cross wall supports a superincumbent 
external wall the whole of such cross wall shall be of the 
thickness prescribed by the bye -law in that behalf for an 
external wall of a party wall of the same height and length 
and belonging to the same class of building as that to which 
such cross wall belongs." 

M.B.L. No. 25 provides for the thickness of walls when 
constructed of other inaterials than bricks : — '* Every person 
who shall erect a new building and shall construct any external 
wall, party wall, or cross wall of such building of any material 
other than good bricks or suitable stone or other blocks of 
hard and incombustible substance, the beds or courses being 
horizontal, shall comply with the following rules with respect 
to the thickness of such wall : — (a) Where a wall is built of 
stone or of clunches of bricks, or other burnt or vitrified 
material, the beds or courses not being horizontal, or of 
flintwork, the thickness of such wall shall be one-third greater 
than that prescribed by the bye-law in that behalf for a 
wall built of bricks, but in other respects of the same descrip- 
tion, height, and length, and belonging to the same class 
of building ; (b) A wall built of brickwork and flintwork, 
in which the proportion of brickwork is equal to at least 
one-fifth of the entire content of the wall and is properly 
distributed in piers and horizontal courses, or of half timber 
work, or of other suitable material not specifically mentioned 
in this bye-law, shall be deemed to be of sufficient thickness 
if constructed of the thickness prescribed by the bye-law 
in that behalf for a wall built of bricks, but in other respects 
of the same description, height, and length, and belonging 
to the same class of building. Provided always that this 
bye -law shall not be deemed to apply to any part of an 
external wall of a new building which may, in accordance 
with the provisions of the bye-law in that behalf, be con- 
structed of timber-framing covered with tiles." 

The next m.b.l. provides for the maximum amount of 
openings that may be put in an external wall : — 

M.B.L. No. 26 : " Every person who shall erect a new 
building and shall leave in any storey or storeys of such 
building an extent of opening in any external wall which 
shall be greater than one -half of the whole extent of the 
vertical face or elevation of the wall or wal's of the storey 



STABILITY OF WALLS. 69 

or storeys in which the opening is left shall construct — (a) 
Sufficient piers of brickwork or other sufficient supports of 
incombustible material so disposed as to carry the super- 
structure ; and (b) A sufficient pier or piers or other sufficient 
supports of that description, at or within 3 ft. of the corner 
or angle of the building." 

M.B.L. No. 27 relates to the prevention of the spread 
of fire from a burning building to an adjacent building : — 
" Every person who shall erect a new public building, a 
new building of the warehouse class, or a new domestic 
building which may be intended to be used wholly or 
partly as a shop or as a place of habitual employment 
for any person in any manufacture, trade, or business, or 
which may be intended to be used exclusively as a dwelling- 
house and may exceed 30 ft. in height, shall cause such 
part of any external wall of such building as is within a 
distance of 15 ft. from any other building to be carried up 
so as to form a parapet 1 ft. at least above the highest part 
of any roof or gutter which adjoins such part of such external 
wall, and he shall cause the thickness of the parapet so carried 
up to be at least 9 in. throughout." 

The succeeding m.b.l. are also directed to the prevention 
of the spread of fire, so far as regards party walls : — 

M.B.L. No. 28a : " (1) Every person who shall erect a 
new public building, a new building of the warehouse class, 
or a new domestic building which may be intended to be 
used wholly or partly as a shop or as a place of habitual 
employment for any person in any manufacture, trade, or 
business, or which may be intended to be used exclusively 
as a dwelling-house and may exceed 30 ft. in height, shall 
cause every party wall of such building to be carried up 
9 in. at the least in thickness : — (a) Above the roof, flat, 
or gutter of the highest building adjoining thereto to such 
height as will give in the case of a public building or of a 
building of the warehouse class, a distance of at least 3 ft., 
and, in the case of any such domestic building as is herein- 
before described, a distance of at least 15 in. measured at 
right angles to the slope of the roof, or above the highest 
part of any flat or gutter, as the case may be : (6) Above 
any turret, dormer, lantern-light, or other erection of com- 
bustible materials fixed on the roof or flat of any building 



70 SANITARY G0N8TBUGTI0N IN BUILDING. 

within 4 ft. from the party wall, and so as to extend at least 
12 in. higher and wider on each side than such erection ; 
(c) To a height of 12 in. at the least above such part of any 
roof as is opposite to and within 4 ft. from the party wall. 
" In every case where the eaves of the roof project beyond 
the face of the building, he shall cause every party wall 
of such building to be properly corbelled out, in brickwork, 
or stonework, to the full extent of such projection, and to 
be carried up above the projecting eaves, 9 in. at the least 
in thickness, to such height as will give, in the case of a 
public building or of a building of the warehouse class, a 
distance of at least 3 ft., and, in the case of any such domestic 
building as is hereinbefore described, a distance of at least 
15 in. measured at right angles to the slope of the roof. 




Fig. 84. — Party Wall Corbelled out and Carried above Eaves. 



" (2) Every person who shall erect a new domestic build- 
ing which may be intended to be used exclusively as a dwelling- 
house and may not exceed 30 ft. in height, or which may 
be intended to be used as an office building or other out- 
building appurtenant to a dwelling-house, whether attached 
thereto or not, shall cause every party wall of such building 
to be carried up at least as high as the underside of the slates 
or other covering of the roof of such building ; and if such 
party wall be carried up only to the underside of such slates 
or other covering, he shall cause such slates or other covering 
to be properly and solidly bedded in mortar or cement on 
the top of the wall. He shall also cause the roof to be so 
constructed that no lath, timber, or woodwork of any descrip- 
tion shall extend upon or across any part of such wall. 



STABILITY OF WALLS. 71 

" (3) For the purposes of this bye-law, the height of a build- 
ing shall be measured upwards from the top of the footings 
of the walls thereof to the level of half the vertical height 
of the roof, or to the top of the parapet, whichever may 
be the higher." 

This apparently complicated regulation will be better 
understood by reference to Fig. 84, which illustrates the 
first two paragraphs. Paragraph (2) needs no illustration. 
In a Note to this bye-law, the annotator points out : — 

" If § 109 of the Towns Improvement Clauses Act, 1847 
(10 & 11 Vict. c. 34), is in force by reason of its iucorporation 
with a local Act, this clause must be omitted. If in any 
case, however, § 109 of the Act of 1847 is not in force, and 
the model clause is regarded as too stringent, the following 
clause must be included so as to secure that all party walls 
are carried up to the underside of the roofs, as it should 
not be permissible to erect houses in rows so that there may 
be uninterrupted intercommunication under a continuous 
roof, as such an arrangement involves great danger from 
the spread, of fire and consequent risk to life, as well as being 
very objectionable from a sanitary point of view in facili- 
tating the spread of certain infectious diseases." 

The following is the alternative bye-law referred to in 
tte Note : — < o; 

M.B.L. No. 28b : "' Every person who shall etect a new 
building shall cause every party wall of such building to 
be carried up at least as high as the underside of the slates 
or other covering of the roof of such building ; and if such 
party wall be carried up only to the underside of such slates 
or other covering, he shall cause such slates or other covering 
to be properly and solidly bedded in mortar or cement on 
the top of the wall. He shall also cause the roof to be so 
constructed that no lath, timber, or woodwork of any descrip- 
tion shall extend upon or across any part of such wall." 

The succeeding m.b.l. explain themselves : — 

M.B.L. No. 29 : " Every person who shall erect a new 
building shall cause every wall of such building, when 
carried up above any roof, flat, or gutter, so as to form 
a parapet, to be properly coped or otherwise protected, in 
order to prevent water from running down the side^ of 
such parapet or soaking into any wall." 



72 SANITARY CONSTRUCTION IN BUILDING. 

M.B.L. No. 30 : "A. person who shall erect a new 
building ehall not construct any party wall of such build- 
ing so that any opening shall be made or left in such 
wall." 

M.B.L. No. 31 : "A person who shall erect a new building 
shall not make any recess in any external wall or party wall 
of such building :— (a) Unless the back of such recess be 
at the least 9 in. thick ; {b) Unless a sufficient arch be turned 
or a lintel of incombustible material placed in every storey 
bvet every such recess ; (c) Unless in each storey the aggre- 
gate extent of recesses having backs of less thickness than 
the thickness prescribed by any bye-law in that behalf for 
the wall in which such recesses are made do not exceed one- 



half of the ext«nt of the vertical superfices of such wall ; 
(d) Unless the side of any such recess nearest to the inner 
face of any return external wall is distant at the least ISJ in. 
therefrom." 

M.B.L. No. 32 : "A person who shall erect a new building 
shall not make in any wall of such building any chase which 
shall be wider than 14 in. or more than 4J in. deep from the 
face of such wallj or shall leave less than 9 in, in thickness 
at the back or opposite side thereof, or which shall be within 
ISJ in. from any other chase, or within 7 ft. from any other 
chase on the same side of such wall, or within 13J in. from 
any return wall." 

M.B.L. No. 33 : "A person who shall erect a new building 
shall not place in any party wall of such building any bond 
timber or any wood plate." 



•STABILITY OF WALLS. 73 

M.B.L. No. 34 : " A person who shall erect a new building 
shall not place the end of any bressummer, beam, or joist 
in any party wall of such building, unless the end of such 
bressummer, beam, or jo'ist be at least 4 J in. distant from 
the centre line of such party wall. Provided always that in the 
case of a party wall not exceeding 9 in. in thickness such 
person may place the end of any such bressummer, beam, 
or joist so that it may extend to the centre line of such party 
wall if the end of such bressummer, beam, or joist be encased 
in not less than 4^ in. of solid brickwork or other solid and 
incombustible material." 

In some cases the proviso is added that this bye-law 
shall not apply to any bressummer, beam, or joist constructed 
wholly of metal. 

M.B.L. No. 35 : " Every person who shall erect a new 
building shall cause every bressummer to be borne by a 
. sufficient template of stone, iron, terra-cotta, or vitrified 
stoneware of the full breadth of the bressummer, and to 
have a bearing in the direction of its length of 4 in. at least 
at each end. He shall also, if necessary, cause such bres- 
summer to have such storey posts, iron columns, stanchions, 
or piers of brick or stone on a solid foundation under the 
same as may be sufficient to carry the superstructure." 

Figs. 85 and 86 indicate methods of construction which 
may be adopted in order to comply with the restrictions 
contained in Bye -laws Nos. 33 and 34. c l signifies centre 
line, F floor, fl flag, j joist, w wall-plate, i b iron bracket. 

The following m.b.l. have reference to chimneys, and 
need no explanatory remarks : — 

M.B.L. No. 36 : " Every person who shall erect a new 
building shall, except in such case as is hereinafter provided, 
cause every chimney of such building to be built on solid 
foundations and with footings similar to the footings of 
the wall against which such chimney is built, and to be 
properly bonded into such wall : Provided, nevertheless, that 
such person may cause any chimney of such building to be 
built on a metal girder, or on sufficient corbels of brick, 
stone, or other hard and incombustible materials, if the 
work so corbelled out does not project from the wall more 
than the thickness of the wall measured immediately below 
the corbel." 



74f SANITARY GONSTRUGTION IN BUILDING, 

M.B.L. No. 37 : " Every person who shall erect a new 
building shall cause the inside of every flue of such building 
to be properly rendered or pargeted as such flue is carried 
up, unless the whole flue shall be lined with fireproof piping 
of stoneware at least 1 in. thick, and unless the spandril 
angles shall be filled in solid with brickwork or other incom- 
bustible materials. Such person shall also cause the back 
or outside of such flue, which shall not be constructed so 
as to form part of the outer face of an external wall, to be 
properly rendered in every case where the brickwork of 
which such back or outside may be constructed is less than 
9 in. thick." 

The M.B.L. contain no provisions for regulating the con- 
struction of chimney shafts ; but the following clause, to 
be modified to suit local requirements, is recommended for 
use in districts where control is desired : — 

M.B.L. No. 37a : " Every person who, in erecting a new 
building, shall construct any chimney shaft for the furnace 
of a steam boiler, brewery, distillery, or manufactory, shall 
comply with the following rules : — (a) He shall cause such 
chimney-shaft to be carried up throughout in brickwork, 
composed of the best hard, well-burnt bricks, laid in lime 
mortar of the best quality, properly bonded and solidly 
put together upon a solid and level bed of good concrete 
of sufficient size and thickness, extending beyond the lowest 
course of footings at least 18 in. on all sides, and having 
a minimum thickness of 18 in. {h) He shall cause the base 
of the shaft to be constructed of solid brickwork to the level 
of the top of the footings, and the footings shall spread 
equally all round the exterior of the base by regular off- 
sets, at least 3 in. high, and 2\ in. wide, to a projection on all 
sides equal at least to the thickness of the brickwork 
enclosing the shaft at the level of the top of the footings, 
(c) He shall cause the external diameter of a shaft measured 
immediately above the footings to be as follows : — Where 
the shaft is square on plan, the external diameter of the 
shaft shall be at least one-tenth of the total height of the 
shaft ; where the shaft is polygonal on plan, the external 
diameter of the shaft shall be at least one -eleventh of the 
total height of the shaft ; where the shaft is circular on plan, 
the external diameter of the shaft shall be at least one- 



STABILITY OF WALLS. 75 

twelfth of the total height of the shaft. In the case of a 
shaft which is square or polygonal on plan, the external 
diameter shall, for the purposes of this bye-law, be measured 
from the centre of one face or side to the centre of the opposite 
face or side, (d) He shall cause the brickwork enclosing 
the shaft to be built with a batter (or inclination inwards) 
of 2^ in. at least in every 10 ft. of height, (e) He shall 
cause the brickwork enclosing the shaft to be at least 9 in. 
in thickness at the top of the shaft and for a distance not 
exceeding 20 ft. below the top, and to be increased in thick- 
ness at least i^ in. for every additional 20 ft. measured down- 
wards. He shall not cause any portion of the work required 
by this paragraph to be constructed of fire-bricks. (/) He 
shall cause the shaft to be provided, for at least one-sixth 
of its height, with an independent lining of fire-bricks, separ- 
ated from the brickwork enclosing the shaft by a cavity 
at least 1 in. in width ; and he shall cause such cavity to be 
covered at the top with corbelled brickwork, (g) The total 
height of the shaft shall, for the purposes of this bye -law, 
be its height measured from the top of the footings." 

M.B.L. No. 38 : " Every person who shall erect a new 
building shall cause every flue in such building which may 
be intended for use in connection with any furnace, cockle, 
steam-boiler, or close-fire, constructed for any purpose of 
trade, business, or manufacture, or which may be intended 
for use in connection with any cooking range or cooking 
apparatus of such building when occupied as an hotel, tavern, 
or eating-house, to be surrounded with brickwork or other 
solid and incombustible material at least 9 in. thick for a 
distance of 10 ft. at the least in height from the floor on 
which such furnace, cockle, steam-boiler, close-fire, cooking 
range, or cooking apparatus may be constructed or placed." 

M.B.L. No. 39 : " Every person who shall erect a new 
building shall cause a sufficient arch of brick or stone, or 
a sufficient stone lintel, or a sufficient bar of wrought-iron 
to be built over the opening of every chimney of such building 
to support the breast of such chimney ; and if the breast 
projects more than 4 J in. from the face of the wall, and the 
jamb on either side is of less width than 13 J in., he shall 
cause the abutments to be tied in by a bar or bars of wrought- 
iron of sufficient strength, 18 in. longer than the opening. 



76 SANITARY GONSTIIUGTION IN BUILDING, 

turned up and down at the ends, and built into the jambs 
on each side." 

M.B.L. No. 40 : " Every person who shall erect a new 
building shall cause the jambs of every chimney of such 
building to be at least 9 in. wide on each side of the opening 
of such chimney." 

M.B.L. No. 41 : " Every person who shall erect a new 
building shall cause the breast of every chimney of such 
building, and the brickwork or stonework surrounding every 
smoke flue and every copper flue of such building, to be 
at least 4J in. in thickness." 

M.B.L. No. 42 : " Every person who shall erect a new 
building shall cause the back of any chimney opening in a 
party wall and [at] the back of the flue connected there- 
with in any room which may be constructed for occupation 
as a kitchen to be at least 9 in. thick to the height of at least 
9 ft. above the hearth. Such person shall cause the back 
of every other chimney opening in such building, from the 
hearth up to the height of 12 in. above such opening, to 
be at least 4^ in. thick in the case of an external wall, and 
9 in. thick in the case of any other wall." 

The bracketed word " at " in the above bye-law has 
been retained in error, and should be omitted. 

M.B.L. No. 43 : " Every person who shall erect a new 
building shall cause the upper side of every flue of such 
building, when the course of such flue makes with the horizon 
an angle of less than 45°, to be at least 9 in. in thickness." 

The following clause relating to the support of chimneys 
on arches formed part of the original model, but has been 
omitted. It may, however, be added in any case where 
it is considered necessary : — 

" Every person who shall erect a new building shall con- 
struct every arch upon which any flue may be carried so 
that such arch shall be effectually supported by means of a 
bar or bars of wrought-iron of adequate strength. He shall 
cause every such bar, to the extent of 4 J in., to be securely 
built or pinned into the wall at each end thereof. He shall 
provide, for every 9 in. of the width of the soffit of such 
arch, one at the least of such bars as a means of support 
for such arch." 

M.B.L. No. 44 : " Every person who shall erect a new 



STABILITY OF WALLS, 77 

building shall cause every chimney shaft or smoke flue of 
such building to be carried up in brickwork or stonework 
all round at least 4 J in. thick to a height of not less than 
3 ft. above the roof, flat, or gutter adjoining thereto, measured 
at the highest point in the line of junction with such roof, 
flat, or gutter." 

M.B.L. No. 45 : "A person who shall erect a new building 
shall not cause the brickwork or stonework of any chimney 
shaft of such building other than a chimney shaft 
of the furnace of any steam-engine, brewery, distillery, 
or manufactory, to be built higher above the roof, flaf, or 
gutt-er adjoining such chimney shaft, measured from the 
highest point in the line of junction with such roof, flat, or 
gutter, than a height equal to six times the least width of 
such chimney shaft at the level of such highest point, unless 
such chimney shaft shall be built with and bonded to another 
chimney shaft not in the same line with such first-mentioned 
chimney shaft, or shall be otherwise made secure." 

M.B.L. No. 46 : "A person who shall erect a new building 
shall not place any iron holdfast or other metal fastening 
nearer than 2 in. to the inside of any flue or chimney -opening 
in such building." 

M.B.L. No. 47 : "A person who shall erect a new building 
shall not place any timber or woodwork — (a) In any wall 
or chimney breast of such building nearer than 9 in. to the 
inside of any flue or chimney - opening ; (b) Under any 
chimney-opening of such building within 10 in. from the 
upper surface of the hearth thereof. A person who shall 
erect a new building shall not drive any wooden plug into 
any wall or chimney breast of such building nearer than 6 in. 
to the inside of any flue or chimney-opening." 

M.B.L. No. 48 : " Every person who shall erect a new 
building shall cause the face of the brickwork or stonework 
about any flue or chimney- opening of such building, where 
such face is at a distance of less than 2 in. from any timber 
or woodwork, and where the substance of such brickwork 
or stonework is less than 9 in. thick, to be properly rendered." 

M.B.L. No. 49 : "A person who shall erect a new building 
shall not construct any chimney or flue of such building 
so as to make or leave in such chimney or flue any opening 
for the insertion of any ventilating valve, or for any other 



78 SANITARY CONSTRUCTION IN BUILDING. 

purpose, unless such opening be at least 9 in. distant from 
any timber or other combustible substance." 

M.B.L. No. 50 : *' A person who shall erect a new building 
shall not fix in such building any pipe for the purpose of 
conveying smoke or other products of combustion, unless 
such pipe be so fixed at the distance of 9 in. at the least 
from any combustible substance." 

It may be pointed out, with regard to the size of chimney 
flues, that this part of the subject is dealt with in the Chinmey 
Sweepers and Chimneys Act, 1840 (3 and 4 Vict. cap. 85), 
where § 6 enacts that " . . . every chimney or flue here- 
after to be built or rebuilt in any wall, or of greater length 
than 4 ft. out of the wall, not being a circular chimney or 
flue 12 in. in diameter, shall be in every section af the 
same not less than 14 in. by 9 in. . . ." No Local 
Authority therefore may adopt any lesser size. 



1 



79 



CHAPTER VI. 

ROOFS. 

M.B.L. No. 51 is designed to prevent the use of thatch, tarred 
felt, and other combustible materials as roof-covering, and 
reads as follows : — 

M.B.L. No. 51 : " Every person who shall erect a new 
building shall cause the flat and roof of such building, and 
every turret, dormer, lantern-light, skylight, or other erection 
placed on the flat or roof of such building, to be externally 
covered with slates, tiles, metal, or other incombustible 
materials, except as regards any door, door frame, window 
or window frame of any such turret, dormer, lantern-light, 
skylight, or other erection." 

The following notes on roof-covering materials are from 
a lecture on this subject by Mr. Keith D. Young, M.San.L, and 
so completely cover the ground that they may be fittingly 
introduced here : — 

" The materials in ordinary use for roofing are tiles, 
slates, lead, zinc, and thatch. Tiles are made in several 
ways ; the plain tile is rectangular in form, with two holes 
at its upper edge, through which the oak or iron pins are 
driven, by which the tile is hung to the lath or batten. The 
pantile is a tile bent to a double curve and furnished with a 
small stub or projection, by which it is hooked on to the 
lath ; variations of this are the double -roll tile and the 
corrugated tile. Taylor's patent tiles are narrower at one 
end than at the other, and have the edges at each side turned 
up ; these are laid alternately as capping and channel tiles. 
The Venetian or Italian tiles have a flat surface alternating 
with a roll. Of all these the plain tile is the best. Tiles 
are, however, heavy, and they absorb a considerable per- 
centage of water, and must therefore be laid at a steeper 
pitch than slates. They are difficult to repair, and, unless 
oedded on some yielding material, are, in exposed situations, 
liable to damage from high winds. For this reason it is 



80 SANITARY CONSTRUCTION IN BUILDING. 

customary in many parts of the country to bed plain tiles 
in rushes, a practice involving the use of material liable 
to decay, which cannot be recommended. The desired 
object can be attained with equal efficiency by bedding the 
tiles in lime and hair. On the other hand, tiles are bad 
conductors of heat, and consequently are a warm covering 
in winter and a cool one in summer. Pantiles are more 
suitable for covering the roofs of out-houses and buildings 
not intended for habitation ; they are, however, universally 
used in the county of Durham and in North Yorkshire. 

" Slates are, as a rule, much thinner and lighter than 
tiles, and, being of a very compact crystalline nature, readily 
admit of the passage of heat and cold through them. The 
best and stoutest slates come from Cumberland ; they are 
usually green in colour, and about J in. thick. They are 
not sorted out into sizes, as are the Welsh slates, but all 
sizes are mixed. When laid on a roof the larger sizes 
are fixed at the eaves, and they gradually decrease 
in size until they reach the ridge, Welsh slates for the most 
part are blue or purple in colour, and are made in certain 
regular sizes, those in most ordinary use being 20 in. by 
10 in., and known as ' countesses.' The best slates are those 
known as Bangor slates, and of these the greater proportion 
come from the famous Penrhyn quarries. The character- 
istics of a good slate are hardness, closeness of texture, and 
small capacity for absorption. It should give a clear ringing 
sound when struck, and its edges should cut clean when 
dressed. A good slate when immersed in water to half its 
length will show no sign of moisture above the water 
line. A good slate also should be free from veins or dark 
streaks, and should not contain lumps of iron pyrites, such 
as are frequently to be seen in an inferior kind of slate imported 
into this country from Germany. 

" Slates, being much less absorbent than tiles, can be 
laid at a much lower pitch. Large slates may be laid at 
an angle of 22°, or a pitch of one-fifth the span ; j)rdinary 
slates, as countesses, at an angle of 26^°, or one-quarter 
the span, and small slates at an angle of 45°, or one-half 
the span. The usual pitch adopted for countess slating 
in practice is J span, giving an angle of about 33°. The 
most important point in laying slating is to allow sufficient 



E00F8. 81 

lap. By lap is meant the distance by which each slate 
overlaps the next slate but one below it. * Gauge ' is the 
depth of margin of each slate exposed below the tail of the 
slate covering it. 

" Slates should always be nailed near the centre in prefer- 
ence to near the head (except in the case of very small slates), 
as the leverage, when acted upon by the wind, is so much 
shorter, and the chance, therefore, of its being blown up 
so much less. Slating so laid is also easier to repair. The 
objection urged to this mode of nailing is that, when a slate 
slips, or gets blown off, the nail heads of the slate below 
are exposed, whereas, with head-nailing, each nail-head is 
covered by two slates, and they would therefore not be 
exposed by the removal of one slate. The lap should never 
be less than 3 in. with countess slates nailed near the centre ; 
the gauge is equal to half the length of the slate, after de- 
ducting the lap. Thus, with a 3-in. lap, the gauge equals 
8 J in., or 20 in. — 3 in. -^ 2 = 8J in. The nail-holes are 
placed near the centre of the slate, but sufficiently near the 
head to clear the head of the slate below. 

" The course of slates next the eaves is always double, 
and is tilted upwards, in order to give a perfectly even bed 
to all the slates, and to prevent the occurrence of any open 
space into which the wind could penetrate. In order to 
preserve a more equable temperature, a layer of boarding 
is sometimes nailed over the rafters, and on this sheet-felt 
is laid, to act as a non-conductor. It is a very good plan 
to fix the slates on battens over the felt, as by so doing an 
air space is obtained between the felt and the slates, which 
further increases the non-conducting property of the former; 
" Lead and zinc are used chiefly for flat roofs. The 
great cost of lead prohibits its use in the smaller class of 
dwellings. It is heavy also, and involves the use of stronger 
framework to support it than is the case with zinc. The 
chief difficulty with lead is its liability to expansion and 
contraction with changes of temperature. For this reason 
no single piece of lead in a flat roof should be larger than 
10 ft. by 3 ft. — a quarter of a sheet. The current at which 
it is laid should not be less than 1 in. in 10 ft., and the sheets 
should be laid lengthwise in the direction of the current. 
Where the sheets join one another lengthwise the lead is 
r 



82 SANITARY GONSTRUGTION IN BUILDING. 

dressed over semicircular wooden rolls, and at the ends a 
drop of 2 in. is formed, the upper and lower lead being dressed 
to overlap. It is important to see that the upper lead does 
not reach down to the lower lead where it overlaps, other- 
wise the water will be sucked under the upper lead by capillary 
attraction. Zinc is laid on very much the same principle 
as lead, but it is important to see that no solder is used in 
fixing it. Zinc is, compared with lead, very light, the stoutest 
zinc weighing 26 oz. to the superficial foot, while for flats 
and gutters the weight of lead should not be less than 7 lb. 
to the foot. 

" Thatch as a roof-covering, notwithstanding its great 
advantage as a most efficient non-conductor of heat, is wholly 
unsuitable for dwelling-houses. It is in effect prohibited by 
the M.B.L. (No. 51) now under consideration, which requires 
that new buildings shall be covered with incombustible 




Fig. 87. — Galvanised Corrugated Iron. 

material. This bye-law is framed under § 157 of the p.h.a., 
1875; which empowers Urban Authorities, and Rural Author- 
ities too, when they have been invested by the l.g.b. with 
certain urban powers as allowed by the p.h.a., 1875, to 
make bye-laws with respect to the structure of walls, founda- 
tions, roofs, and chimneys of new buildings for securing 
stability and the prevention of fires and for the purposes 
of health, and is clearly directed at that part of the section 
which relates to the prevention of fire ; but with regard 
to thatch, the question of health is of equal importance to 
that of fire. Thatch is an absorbent substance liable to 
decay, and has been proved to have the power of retaining 
the infective germs of specific disease for an almost unlimited 
period. For these reasons thatch must be imhesitatingly 
condemned as a roof-covering for dwelling-houses. Such a 
material as tarred felt also, though possibly not so absorbent 
as and less liable to decay than thatch, is of a most com- 
bustible nature, and as such would come under the pro- 



BOOFS, 83 

hibition of the bye-law. Thatch has the further disadvantage 
that it does not permit of eaves- gathering, and consequently 
the rain-water from the roof cannot well be collected, and 
is allowed to drip on the ground so as to involve dampness 
in walls and foundations." 

Sheet copper has been strongly advocated as a roof- 
covering, but there are very few who disregard expense 
when erecting a house, and consequently very few buildings 
are roofed with copper. It has, however, qualities that give 
it a high place among roof- coverings. It can be hammered 
and shaped to any form without injury ; and, resisting 
oxidation and acids, it is found to last much longer' than 
other metallic coverings. It is more durable than lead as 
a material for bearing traffic. Against lead, moreover, it 
possesses this important advantage, that it may be used 
at one-fifth the weight of lead ; a building which would 
require 5 or 6 tons of lead to keep it weather-proof may be 
rendered equally secure, and for as long a time, with 1 ton 
of copper. In case of fire, also, while molten lead would 
pour down in streams, copper would remain iminjured. As 
against zinc, copper certainly is twice as costly to start 
with, but its durability may be taken to be three or four 
times that of zinc. 

Galvanised corrugated iron is also apparently permissible 
under the bye-law, but its use should never be allowed where 
it can be prevented. It is formed of sheet iron bent to 
a wavy form (see Fig. 87), and is covered with a thin coating 
of zinc by dipping it in a bath of molten metal. It is sup* 
posed to be thus rendered non-corrodible. In practice, it is 
found to rust away very quickly ; minute defects in the 
galvanising allow the acids of the smoke -laden atmosphere 
to be carried in by the rain, and even the most substantial 
work is rusted through in a very few years. 

Concrete and asphalt roof -coverings are allowable, but 
great care is necessary to ensure their being constructed 
water-tight. 

Duroline, a substance invented a few years ago, is com- 
posed of steel wire gauze thickly covered with a varnish 
or similar material ; and being translucent, it was recom- 
mended as a substitute for glass in skylights. In the case 
of Payne v. Wright, however, it was held not to be " incom- 



84 SANITARY G0N8TBUGTI0N IN BUILDING. 

bustible material " (8 " Times Law Reports," 54), and conse- 
quently its use is prohibited wherever m.b.l. No. 51 has been 
adopted. 

The M.B.L. contain no provisions with respect to the con- 
struction of roofs ; but in an additional series prepared 
under the direction of Messrs. Knight and Co. (see Knight's 
Annotated Edition, pp. 194 et seq.), and approved by the 
L.G.B., the subject is fully dealt with as follows : — 

" Roofs. — Every person who shall erect a new building 
shall, as regards the construction of the roof of such building, 
comply with such of the following rules as may be applicable 
to such building, that is to «ay : — 

" (i) Common Rafters. — He shall in the construction of 
the roof of a domestic building, public building, or building 
of the warehouse class, cause every common rafter to be 
of not less than the size and strength following : — (a) If 
the rafter does not exceed 6 ft. in clear bearing, it shall 
be 3 in. in depth and 2 J in. in thickness. (6) If the rafter 
exceeds 6 ft. and does not exceed 7 J ft. in clear bearing, 
it shall be 3 in. in depth and 3 in. in thickness, (c) If the 
rafter exceeds 7^ ft. and does not exceed © ft. in clear bearing, 
it shall be 4 in. in depth and 3 in. in thickness. 

" (ii) Purlins. — He shall in the construction of the roof 
of a domestic building, public building, or building of the 
warehouse class, cause every purlin to be of not less than 
the size and strength following : — (a) If the purlins do not 
exceed 6 ft. 4 in. in clear bearing, and are not more than 
6 ft. apart, each purlin shall be 5 in. in depth and 3 in. in 
thickness, or if more than 6 ft. and not more than 7 J ft. 
apart, each purlin shall be 5J in. in depth and 3 in. in thick- 
ness, or if more than 7J ft. and not more than 9 ft. apart, 
each purlin shall be 6 in. in depth and 3 in. in thickness. 

(b) If the purlins exceed 6 ft. 4. in. and do not exceed 
8 ft. 4 in. in clear bearing, and are not more than 6 ft. 
apart, each purlin shall be 6 in. in depth and 4 in. in 
thickness, or if more than 6 ft. and not more than 
7J ft. apart, each purlin shall be 6J in. in depth and 
4 in. in thickness, or if more than 7 J ft. and not more than 9 ft. 
apart, each purlin shall be 7 in. in depth and 4 in. in thickness. 

(c) If the purlins exceed 6 ft. 4 in. and do not exceed 10 ft. 4 in. 
in clear bearing, and are not more than 6 ft. apart, each 



BOOFS. 85 

purlin shall be 7 in. in depth and 5 in. in thickness, or if 
more than 6 ft. and not more than 7J ft. apart, each purlin 
shall be TJ in. in depth and 5 in. in thickness, or if more 
than 7^ ft. and not more than 9 ft. apart, each purlin shall 
be 8 in. in depth and 5 in. in thickness, (d) If the purlins 
exceed 10 ft. 4 in. and do not exceed 12 ft. 4 in. in clear 
bearing, and are not more than 6 ft. apart, each purlin shall 
be 8 in. in depth and 6 in. in thickness, or if more than 6 ft. 
and not more than 7J ft. apart, each purlin shall be 8^ in. 
in depth and 6 in. in thickness, or if more than 7^ ft. and 
not more than 9 ft. apart, each purlin shall be 9 in. in depth 
and 6 in. in thickness, {e) If the purlins exceed 12 ft. 4 in. 
and do not exceed 14 ft. 4 in. in clear bearing, and are not 
more than 6 ft. apart, each purlin shall be .9 in. in depth 
and 6 in. in thickness, or if more than 6 ft. and not more 
than 7| ft. apart, each purlin shall be 9J in. in dep^h and 
6 in. in thickness, or if more than 7 J ft. and not more than 
9 ft. apart, each purlin shall be 10 in. in depth and 6 in. 
in thickness. (/) If the purlins exceed 14 ft. 4 in. and do 
not exceed 16 ft. 4 in. in clear bearing, and are not more 
than 6 ft. apart, each purlin shall be 11 in. in depth and 
6 in. in thickness, or if more than 6 ft. and not more than 
7 J ft. apart, each purlin shall be 11^ in. in depth and 6 in. 
in thiclmess, or if more than 7J ft. and not more than 9 ft. 
apart, each purlin shall be 12 in. in depth and 6 in. in thick- 
ness, (g) If the purlins exceed 16 ft. 4 in. and do not exceed 
18 ft. 4 in. in clear bearing, and are not more than 6 ft. apart, 
each purlin shall be 11 in. in depth and 7 in. in thickness, 
or if more than 6 ft. and not more than 7 J ft. apart, each 
purlin shall be 11 J in. in depth and 7 in. in thickness, or 
if more than 7J ft. and not more than 9 ft. apart, each purlin 
shall be 12 in. in depth and 7 in. in thickness." 

The conveying of rainwater from a roof to the drain 
is provided for in Urban Districts by § 74 of the Towns 
Improvement Clauses Act, 1847, which reads as follows, : — 

" The occupier of every house or building in, adjoining, 
or near to any street shall, within seven days next after 
service of an Order of the Commissioners for that purpose, 
put up and keep in good condition a shoot or trough of the 
whole length of such house or building, and shall connect 
the same either with a similar shoot on the adjoining house, 



86 SANITARY CONSTRUCTION IN BUILDING. 

or with a pipe or trunk to be fixed to the front or side of 
such building from the roof to the ground, to carry the 
water from the roof thereof, in such a manner that the water 
from such house, or any portico or projection therefrom, 
shall not fall upon the persons passing along the street or 
flow over the footpath ; and in default of compliance with 
any such order within the period aforesaid, such occupier 
shall be liable to a penalty not exceeding 40s. for every day 
that he shall so make default." 

§ 160 of the P.H.A., 1875, gives the Local Authority power 
to serve the Order upon the owner, and allows the occupier, 
if he carries out the work, to deduct the cost from the rent. 
In the district of a Rural Sanitary Authority this law does 
not apply, and the Local Authority should adopt the follow- 
ing bye-laws : — 

" A. — Every person who shall erect a new building shall 
cause the roof or flat of such building to be so constructed 
that all water falling on such roof or flat shall be received 
in suitable gutters, shoots, or troughs, and shall thence 
be discharged into a pipe or trunk provided in pursuance 
of the bye -law in that behalf. 

" B. — Every person who shall erect a new building shall 
cause a suitable pipe or trunk, extending from the roof of 
such building to the ground, to be fixed to the front or 
rear or to one of the sides of such building, and to be so 
connected with a gutter, shoot, or trough receiving any 
water that may fall on the roof, as to carry all such water 
therefrom without causing dampness in any part of any 
wall or foundation of such building." 

Wherever a roof of an existing building is defective, the 
sanitary inspector will deal with it as with damp walls (see 
pp. 55-56), and declare it a nuisance and injurious to health, 
and cause an Order to Abate to be served on the owner. 

The same course should be taken where any existing 
building in rural districts is without eaves gutters and down- 
pipes. 



87 



CHAPTER VIL 

FLOORS, HEARTHS, AND STAIRCASES. 

Section 157 of the p.h.a., 1875, was extended by the Amend- 
ment Act of 1890, "so as to empower every Urban Autho- 
rity to make bye-laws with respect to . . . the structure 
of floors, hearths, and staircases, and the height of rooms 
intended to be used for human habitation," etc. The approved 
bye-law dealing with the construction of floors reads as 
follows : — 

" Floors. — Every person wKo shall erect a new building 
shall, as regards the structure of every floor of such building, 
comply with such of the following rules as may be applicable 
to such building, that is to say : — 

" Domestic Buildings. — Joists. — (i) He shall, in the con- 
struction of the floor of a domestic building, cause every 
common bearing joist to be of not less than the size and 
strength following : — (a) If the joist does not exceed 3 ft. 
4 in. in clear bearing, it shall be 3 in. in depth and 3 in. in 
thickness. (6) If the joist exceeds 3 ft. 4 in. and does not 
exceed 5 ft. 4 in. in clear bearing, it shall be 3J in. in depth 
and 3 in. in thickness, (c) If the joist exceeds 5 ft. 4 in. and 
does not exceed 7 ft. 4 in. in clear bearing, it shall be 4 in. 
in depth and 3 in. in thickness, (d) If the joist exceeds 
7 ft. 4 in. and does not exceed 9 ft. 4 in. in clear bearing, 
it shall be 5 in. in depth and 2J in. in thickness, (e) If 
the joist' exceeds 9 ft. 4 in. and does not exceed 11 ft. 4 in. 
in clear bearing, it shall be 6 in. in depth and 2J in. in thick- 
ness. (/) If the joist exceeds 11 ft. 4 in. and does not exceed 

13 ft. 4 in. in clear bearing, it shall be 7 in. in depth and 
2 J in. in thickness, (g) If the joist exceeds 13 ft. 4 in. and 
does not exceed 14 ft. 4 in. in clear bearing, it shall be 7 in. 
in depth and 3 in. in thickness, (h) If the joist exceeds 

14 ft. 4 in. and does not exceed 16 ft. 4 in. in clear bearing, 
it shall be 8 in. in depth and 3 in. in thickness, (i) If the 
joist exceeds 16 ft. 4 in. and does not exceed 18 ft. 4 in. in 



88 8ANITABY CONSTRUCTION IN BUILDING, 

clear bearing, it shall be 9 in. in depth and 3 in. in thickness. 
(;*) If the joist exceeds 18 ft. 4 in. and does not exceed 20 ft. 
4 in. in clear bearing, it shall be 10 in. in depth and 3 in. 
in thickness, (k) If the joist exceeds 20 ft. 4 in. and does 
not exceed 22 ft. 4 in. in clear bearing, it shall be 11 in. in 
depth and 3 in. in thickness. 

" Trimming and Trimmer Joists. — {J) A trimmer joist 
shall not receive more than six common joists, and the thick- 
ness of a trimming joist receiving a trimmer at not more 
than 3 ft. from one end, and of every trimmer joist receiving 
not more than six common joists, shall be 1 in. greater than 
the thickness hereinbefore specified for a common joist of 
the same bearing. 

" Beam^. — (ii) He shall, in the construction of the floor 
of a domestic building, cause every beam or girder of such 
floor, which is not used to support any wall, pier, or other 
similar structure, to be of not less than the size and strength 
following : — (a) If the beam exceeds 8 ft. and does not 
exceed 10 ft. in clear clearing, it shall be 10 in. in depth 
and 6 in. in thickness. (6) If the beam exceeds 10 ft. 
and does not exceed 12 ft. in clear bearing, it shall be 11 in. 
in depth and 7 in. in thickness, (c) If the beam exceeds 
12 ft. and does not exceed 14 ft. in clear bearing, it shall 
be 12 in. in depth and 8 in. in thickness, {d) If the beam 
exceeds 14 ft. and does not exceed 16 ft. in clear bearing, 
it shall te 13 in. in depth and 9 in. in thickness, (e) If the 
beam exceeds 16 ft. and does not exceed 18 ft. in clear bear- 
ing, it shall be 14 in. in depth and 10 in. in thickness. (/) 
If the beam, exceeds 18 ft. and does not exceed 20 ft. in clear 
bearing, it shall be 15 in. in depth and 11 in. in thickness. 

" Warehxmse Buildings. — Joists. — (iii) He shall, in the 
construction of the floor of a building of the warehouse class, 
cause every common bearing joist to be of not less than 
the size and strength following : — (a) If the joist does 
not exceed 3 ft. in clear bearing, it shall be 4J in. in depth 
and 3 in. in thickness. (6) If the joist exceeds 3 ft. and 
does not exceed 4 ft. in clear bearing, it shall be 6 in. in 
depth and 2J in. in thickness, (c) If the joist exceeds 

4 ft. and does not exceed 5 ft. in clear bearing, it shall be 
7 in. in depth and 2J in. in thickness {d) If the joist exceeds 

5 ft. and does not exceed 6 ft. in clear bearing, it shall be 



FLOORS^ HEARTHS, AND STAIRCASES. 89 

7 in. in depth and 3 in. in thickness, (e) If the joist exceeds 

6 ft. and does not exceed 7 ft. in clear bearing, it shall be 
7^ in. in depth and 3 in. in thickness. (/) If the joist exceeds 

7 ft. and does not exceed 8 ft. in clear bearing, it shall be 

8 in. in depth and 3 in. in thickness, (g) If the joist exceeds 
8 ft. and does not exceed 10 ft. in clear bearing, it shall 
be 9 in. in depth and 3 in. in thickness, (h) If the joist 
exceeds 10 ft. and does not exceed 12 ft. in clear bearing, 
it shall be 10 in. in depth and 3 in. in thickness, (i) If the 
joist exceeds 12 ft. and does not exceed 14 ft. in clear 
bearing, it shall be 11 in. in depth and 3 in. in thickness. 
{]) If the joist exceeds 14 ft. and does not exceed 16 ft. 
in clear bearing, it shall be 12 in. in depth and 3 in. in thick, 
ness. (k) If the joist exceeds 16 ft. and does not exceed 
18 ft. in clear bearing, it shall be 13 in. in depth and 3^ in. 
in thickness. (/) If the joist exceeds 18 ft. and does not 
exceed 20 ft. in clear bearing, it shall be 14 in. in depth and 
4 in. in thickness. 

" Trimming and Trimmer Joists. — (m) A trimmer joist 
shall not receive more than six common joists, and the thick- 
ness of a trimming joist receiving a trimmer at not more 
than 3 ft. from one end shall be 1^ in. greater than the thick- 
ness hereinbefore specified for a common joist of the same 
bearing ; and the thickness of a trimmer joist receiving 
not more than six common joists shall, for every such joist, 
be increased by J in. additional to the thickness hereinbefore 
specified for a common joist of the same bearing. 

" Beams. — (iv) He shall, in the construction of the floor 
of a building of the warehouse class, cause every beam or 
girder of such floor which is not used to support any wall, 
pier, or other similar structure, to be of not less than the 
size and strength following : — (a) If the beam exceeds 
8 ft. and does not exceed 10 ft. in clear bearing,^ it shall 
be 12 in. in depth and 11 in. in thickness. (6) If the beam 
exceeds 10 ft. and does not exceed 12 ft. in clear bearing, 
it shall be 13 in. in depth and 12 in. in thickness, (c) If the 
beam exceeds 12 ft., and does not exceed 14 ft. in clear 
bearing, it shall be 14 in. in depth and 13 in. in thickness. 
(d) If the beam exceeds 14 ft. and does not exceed 16 ft. 
in clear bearing, it shall be 15 in. in depth and 14 in. in thick- 
ness, (e) If the beam exceeds 16 ft. and does not exceed 



90 SANITARY CONSTRUCTION IN BUILDING. 

18 ft. in clear bearing, it shall be 18 in. in depth and 15 in. 
in thickness. (/) If the beam exceeds 18 ft., and does not 
exceed 20 ft. in clear bearing, it shall be 24 in. in depth and 
15 in. in thickness. 

" Public Buildings. — (v) He shall, in the construction 
of every floor of a public building, not being a floor in a 
small room intended to be used for private purposes, or of 
an ant^e-room, cause every bearing joist and every beam 
or girder of such floor which is not used to support any wall, 
pier, or other similar structure, to be of a sufficient and 
proper depth and thickness for the purpose for which it is 
intended, such depth and thickness, in every case where 
such joists are laid and fixed at distances of not more than 
12 in. apart, and where such beams are laid and fixed at 
not more than 8 ft. apart, measured in either case from 
the middle of one joist or beam to the middle of the next 
or to the nearest wall, being not less than the thickness 
hereinbefore prescribed for joists and beams of domestic 
buildings, and in every other case the depth and thickness 
being one-fifth greater than the depth and thickness so pre- 
scribed." 

Then follow general regulations afEecting the construction 
of both roofs and floors : — 

" General Rules. — The requirements of the preceding 
bye-laws relating to roofs and the structure of floors shall 
be subject to the following rules, that is to- say : — 

(1) The sizes and strengths hereinbefore prescribed apply 
only to beams, joists, purlins, and rafters of any species 
of fir or pine of sound and good quality, and if any other 
kind of wood is used the size and strength of every beam, 
joist, purlin, and rafter shall be such as may be adequate 
to secure due stability. 

(2) The sizes prescribed for the tiiAbers mentioned in 
the foregoing rules shall represent the least size and strength 
which any such timber may have at any part. 

(3) Every beam, joist, purlin, and rafter shall be laid 
and fixed on edge, its greatest side being in a vertical position, 
or nearly so, as may be requisite, and when laid and fixed 
in such position, the distance between the upper and lower 
surfaces thereof shall, for the purposes of this bye-law, be 
deemed to be the depth thereof. 



FLOORS, HEALTHS, AND STAIRCASES, 91 

(4) In calculating the size and strength required for 
any beam or other timber intended to be of a strength equal 
to or greater than that of any particular beam or other 
timber of the same length and of the dimensions specified 
in the bye-law in that behalf, the following method shall 
be adopted : In both cases the number of inches in the 
depth of such beam or other timber shall be multiplied by 
itself and the product shall be multiplied by the number 
of inches in the breadth. The number thus obtained shall 
be taken to represent the strength of such beam or other 
timber. 

(5) The rtdes relating to joists and beams in floors are 
applicable only to floors formed of joists laid on edge in 
the ordina'ry way and covered with boards. 

(6) In the case of a framed floor, or of a floor formed 
with beams at short distances apart, and covered with battens, 
deals, or planks, without joists, the several timbers of such 
floor shall be of such size and strength as may be adequate 
to secure due stability. 

" (7) The rules relating to joists and beams in floors 
are applicable only to joists laid at a distance of not more 
than 15 in. apart, measured from the middle of one joist 
to the middle of the next or to the nearest wall, and to beams 
laid at a distance of not more than 10 ft. apart, measured 
from the middle of one beam to the middle of the next or 
the nearest wall. And joists and beams, not exceeding 
the dimensions specified in the foregoing rules, shall be 
laid and fixed at not more than the aforesaid distances apart, 
namely, 15 in. and 10 ft. respectively : (i) Provided that 
in the case of a floor formed of joists or beams of greater 
dimensions J;han the respective dimensions specified, such 
joists or beams may be laid and fixed at a proportionately 
greater distance apart than 15 in. and 10 ft. respectively ; 
and (ii) In the case of a floor formed of joists or beams of 
less dimensions than the respective dimensions specified, 
or of timber of inferior quality, such joists or beams shall 
be laid and fixed at a proportionately less distance apart 
than 15 in. and 10 ft. respectively. 

" (8) In the case of a floor in which any joist or beam 
is of a length for which no provision is made in the fore- 
going rules, such joist or beam shall be of such size and 



92 SANITARY CONSTRUCTION IN BUILDING, 

strength as may be adequate to secure due stability, and 
in any case where herring-bone strutting is constructed 
between joists, the size and strength of such joists may be 
reduced by such an amount as is equivalent to the strength 
represented by the strutting. 

" (9) The rules relating to rafters and purlins in roofs 
are applicable only to roofs formed of rafters ajid purlins 
laid in the ordinary way and covered with slates of the usual 
kind. 

" (10) In the case of a roof formed of coupled rafters 
or of rafters laid horizontally, or in the case of a boarded 
roof covered with slates, or in the case of a roof covered with 
glass, lead, tiles, stone, iron, cement, or other material not 
being slates of the usual kind, the several timbers of such 
roof shall be of such size and strength as may be adequate 
to secure due stability. 

" (11) The rules relating to rafters and purlins in roofs 
are applicable only to rafters laid at a distance of not more 
than 15 in. apart, measured from the middle of one rafter 
to the middle of the next or to the nearest wall, and to purlins 
laid at a distance of from 6 to 9 ft. apart, measured from 
the middle of one purlin to the middle of the next or to the 
ridge or to the bearing upon the wall. And rafters and 
purlins not exceeding the dimensions specified shall be laid 
and fixed at not more than the aforesaid distances apart, 
namely, 15 in. and 9 ft. respectively : Provided that — (i) In 
the case of a roof formed of rafters or purlins of greater 
dimensions than the respective dimensions specified, such 
rafters or purlins may be laid and fixed at a proportionately 
greater distance apart than 15 in. and 9 ft. respectively, (ii) 
In' the case of a roof formed of rafters or purlins of less dimen- 
sions than the respective dimensions specified, such rafters or 
purlins shall be laid and fixed at a proportionately less 
distance apart than 15 in. and 6 ft. respectively. 

" (12) In the case of a roof in which any rafter or purlin 
is of a length for which no provision is made in the fore- 
going rules, such rafter or purlin shall be of such size and 
strength as may be adequate to secure due stability." 

Cellar floors should be impervious to wet, non-porous, 
easily kept clean, smooth, and inodorous. Where the m.b.l. 
No. 11 has been carried out, and there is a layer of concrete 



FLOORS, HEARTHS, AND STAIRCASES. 93 

or asphalt all over the site, there exists only a necessity 
for a covering layer which shall fulfil the other conditions. 
This may be a coating of 1 in. thick of portland cement 
and granite dust, in equal proportions, and carefully trowelled 
until the surface is as smooth and hard as polished slate ; 
or the coating may be a layer of vitrified bricks or tiles set 
in hydraulic mortar or portland cement ; or good hard 
non-porous flags ; or a 1-in. layer of rock-asphalt (tar asphalt 
is too odorous) ; or wood-block flooring, where the blocks 
are well seasoned and laid in asphaltic cement on the con- 
crete.' Wood-blocks are, however, somewhat dangerous in 
a basement, on account of the possibility of dry-rot finding 
a lodgment there, and rendering it necessary to have the 
whole floor taken up and removed. 

Sometimes it is necessary to lay a basement floor, where 



Fig. 88. — Basement Floor Laid below Mean Water Level. 

the ream water level is above the floor level ; in which case 
special precautions must be taken. From Fig. 88 — illus- 
trating the construction of a floor in Canning Town, laid 
several feet below water-level, where the upward pressure on 
the floor was between 600 lb. and 700 lb. per square foot — 
it will be seen that rolled iron joists a, 15 in. by 12 in., were 
laid at 12-ft. centres, being pinned into the wall at each 
end ; the surface of the ground was trimmed to the requisite 
level, earthenware drain-tubes b being inserted in the porous 
clay and mud to carry off the water during the execution 
of the work ; on this was laid clay puddle c, and the con- 
crete inverted arches d were then put in. After they had 
set, the floor was levelled up with concrete e, and covered 
with asphalt p ; 5-in. rolled iron joists were also placed 
about 4 ft. apart on the bottom flange of the 15-in. by 12-in. 
joists. G shows hoop-iron tarred and laid in concrete. There 
are many other expedients for dealing with similar problems. 



94 SANITARY CONSTRUCTION" IN BUILDING. 

The living-rooms of a house are generally those on the 
ground-floor, and for the&3 the ordinary boarded floor is the 
most comfortable. The boards should be tongued and 
grooved, well seasoned, and well laid, especially when there 
is no cellar below. 

In one respect the ordinary floor is exceedingly insanitary : 
it is a convenient place for the gas-pipes ; it is sometimes, 
though rarely, used for purposes of ventilation ; but it is 
otherwise little cared for, and forms a happy hunting ground 
for the mice, if not for more objectionable vermin. At 
present the sanitary inspector cannot deal with it, unless 
and imtil it becomes bad enough to be dealt with under 
the " nuisance " section of the p.h.a., 1875. It h«^s been 




'Pis. 89.— Solid Plank Floor. 



suggested to fill the space with slag-wool, with sterilised 
sawdust, peat moss, etc. 

Mr. Joseph Corbett, M.San.I., in a paper before the 
Sanitary Congress at Bolton, in 1887, advocated a floor made 
of planks 3 in. thick, tongued, grooved, and bolted together. 
He said that the floor of each room could be completely 
prepared in the workshop ; the separate planks being machine- 
planed, squared, and grooved ; two 1-in. bolt-holes bored 
laterally through each plank ; hoop-iron tongues inserted 
in the grooves ; bolts inserted from side to side of the set 
of planks and screwed up tight ; the surface dressed off, 
and the complete slab of flooring conveyed to its place and 
laid down on salient courses in the room walls prepared to 
receive it (see Fig. 89). 

In many cases it would be more economical to make 
each room floor in three pieces, joined together by an imder 



FLOORS, HEARTHS, AND STAIRCASES. 95 

board and coacli screws. The shrinkage could be easily 
taken up bj tightening the through bolts. The chink round 
the walls would be flushed with cement ; and thus a strong, 
warm, draught-proof, vermin-proof floor would be made at 
a cost not exceeding that of a common floor and plaster 
ceiling. Such plank-floors are more sound-proof than ordinary 
floors, and are very nearly fire-proof. Where the rooms 
were wider than 12 ft., the planks would have to be 3^ in. 
or 4 in. deep to be able to span the increased distance. There 
are two other economies resulting from their use ; they 
save one step in each flight of stairs, and in the height of 
the walls ; and being put into position as soon as the sup- 
porting salient courses are set, they may be protected by 
boards, and used as scaffolding, saving the cost of the latter. 

Many other materials for floors have been suggested 
and used, but not often in the average dwelling-house, and 
therefore it will be of no use to discuss them ; steel joists, 
however, may be mentioned, and brick arches, or concrete, 
or tile arches, either with or without an upper surface of 
boards, cork, papier-mache, etc. Often it happens that, 
owing to the shrinkage of floor boards, a nasty crevice is 
left between them, admitting draughts, harbouring dirt, 
vermin, and infection, and becoming a danger to health. 
These crevices may either be filled up with strips of wood, 
or with one of several compositions, such as thin glue and 
sawdust, paste and sawdust, plaster-of-Paris, sawdust and 
water, oakum, etc. One, however, that is most highly recom- 
mended is to thoroughly soak old newspapers in paste made 
of 1 lb. of flour, 3 quarts of water, a tablespoonfiil of alum, 
the paste to be thoroughly boiled ; when properly made it 
will be as thick as putty, and the filling will harden like papier- 
mache. 

While considering floors and their facilities for becoming 
dirt receptacles, we are reminded of skirtings. On this 
point the p.h.a. are silent, and consequently there is no power 
to make bye-laws on the subject. There is ample room for a 
regulation to prevent the leaving of spaces behind skirtings ; 
these, even more than the hollows in floors, are the haunts 
of mice and other vermin (see Fig. 90). The plaster of the 
walls should be carried right down to the flooring boards ; 
in the inferior rooms of houses, such as kitchens, smaller 



96 SANITARY G0N8TRUGTI0N IN BUILDING. 

bedrooms, etc., the skirting might with advantage be formed 
of Portland cement (see Fig. 91). 

There are other points upon which the Acts are silent. 
Plaster for walls is not mentioned, and, imless a town has a 
private Act of ParKament including this word, a builder 
may use any material which will stick upon the walls, pro- 
viding it is clean. If it is foul, the sanitary inspector may 
put into force the " nuisance " clause of the 1875 Act. Ceil- 
ings are not mentioned, and a builder may use timber of 
any strength, if only it will not fall down. Wall-plates, ridge 
pieces, cornices, and many other portions of a house are 
omitted, as is also the size of rooms. 

The next item with respect to which bye -laws can be 



Fig. 90. — Ordinary Skirtings. 



Fig, 91. — Skirting Made of 
Portland Cement. 



made is hearths, and the clause which has been approved 
is as follows : — 

" With respect to Hearths. — 5. A person who shall erect 
a new building shall place and fix in front of every chimney - 
opening in such building a proper hearth of stone, slate, 
bricks, tiles, or other incombustible substance, at the least 
6 in. longer at each end than the width of such opening, 
and projecting not less than 18 in. distant from the chimney- 
breast. He shall cause such hearth to be laid at the level 
of the floor of the room in which such chimney-opening is 
situated, and to be borne wholly upon stone or iron bearers, 
or upon a brick trimmer arch (see Fig. 92), and bedded 
wholly on brick, stone, or other incombustible substance, 
extending to a depth of 7 in. at the least beneath the upper 
surface of the hearth, provided that in the lowest storey 
the hearth may be bedded on the solid ground." 



FLOORS, HEARTHS, AND STAIEGASES, 



97 



This regulation, it will be seen, is more for the prevention 
of fires than for the purposes of health. 

With regard to staircases the 1890 Act gives a Local 
Authority power to make complete bye-laws as to the struc- 
ture and materials. The bye-laws drawn up by Messrs. 
Knight & Co. read as follows : — 

" With respect to Floors and Staircases. — 9. Every person 
who shall erect a new public building shall construct the 
floor of every lobby, corridor, passage, and landing, and 
every flight of stairs in any staircase in such building, and 




Fig. 92. — Section through Hearth showing Brick Trimmer. 



all the supports of every such floor and flight of stairs, of 
stone or other incombustible material, and of adequate 
strength. Provided always, that the foregoing requirements 
shall not apply to the floor of a lobby, corridor, passage, 
or landing, or to any flight of stairs intended to be used 
otherwise than as means of access to any part of a public 
building intended to be used for any public purpose. 

" 9a. Every person who shall erect a new public building 
shall construct the floor of every lobby, corridor, passage, 
and landing therein, which is not intended solely as a means 
of access to any private apartment, and all the supports 
of every such floor, of stone or other incombustible or fire- 
resisting materials, and of adequate strength. 

" 9b. Every person who shall erect a new public building 
or a new building of the warehouse class, and shall construct 
any staircase therein, shall cause every flight of stairs in such 
staircase to be properly constructed of sound and suitable 
materials, and to be securely fixed and of adequate strength. 

6 



98 SANITARY CONSTRUCTION IN BUILDING, 

He shall in the case of a public building cause every flight 
of stairs in such staircase which is not intended solely as 
a means of access to any private apartment to be constructed 
of incombustible materials, and carried by supports of incom- 
bustible materials, and to be furnished on each side with 
a sufficient handrail, properly and securely fixed. He shall 
in the case of a public building cause every flight of stairs 
in such staircase which is intended solely as a means of access 
to any private apartments to be provided with a sufficient 
handrail, properly and securely fixed. 

" 9c. Every person who shall erect a new building which 
shall be intended for use as a dwelling-house for separate 
families, and which shall contain more than 125,000 cub. ft., 
shall cause the floor of every landing, corridor, passage, and 
lobby, and every flight of stairs in any staircase in such 
building, and all the supports of every such floor and flight 
of stairs to be constructed of stone or other incombustible 
and fire -resisting material. 

'* 9d. Every person who shall erect a new domestic 
building containing separate sets of chambers or offices 
or rooms constructed or intended or adapted to be tenanted 
by different persons, and which shall exceed 50,000 ft. in 
cubical extent, shall construct the floor of every lobby, 
corridor, passage, and landing, and every flight of stairs 
in any staircase in such building, and all the supports of 
every such floor and flight of stairs of stone or other fire- 
resisting material and of adequate strength, and shall cause 
the principal staircase and landings of such building to be 
enclosed with walls, not less than 9 in. in thickness, con- 
structed of good hard, sound, well-burnt bricks, stone, or 
other hard and incombustible materials, properly bonded 
and solidly put together, (a) With good mortar compounded 
of good fresh-burnt lime and clean, sharp sand, or of good 
fresh-burnt lime and a mixture of 1 part of sand and 2 parts 
of burnt ballast, broken bricks, stones, furnace or forge 
ashes, ground sufficisntly fine and properly mixed with the 
lime in the proportion of 1 part of lime to 3 parts of sand 
or grit ; or (b) with good cement ; or (c) with good cement 
mortar, compounded of good cement, mixed with clean, 
sharp sand or grit as aforesaid in the proportion of 1 part 
of cement to 4 parts of sand or grit. He shall also construct 



FLOORS, HEARTHS, AND STAIRCASES. 99 

the floor of every scullery and water-closet above the ground 
floor of concrete of other impermeable material. 

" 9e. Every person who shall erect a new domestic 
building and shall construct any staircase therein shall 
comply with the following requirements : that is to 
say— 

" (1) He shall cause the woodwork of every flight of 
stairs in such staircase to be of not less than the following 
thicknesses, viz. : — (a) The strings shall not be less than 
IJ in. in thickness. (6) The treads shall not be less than 
1 in. in thickness, (c) The risers shall not be less than f in. 
in thickness. 

" (2) He shall cause the treads to be not less than 8 in. 
in width, measured horizontally, from face of riser to face 
of riser, and the risers to be not more than 9 in. in 
height, measured vertically from top of tread to top of 
tread. 

" (3) He shall cause such staircase to be provided with 
a sufficient handrail, properly and securely fixed. 

" 9f. Every person who shall construct a room for habit- 
able purposes over a stable shall so construct the floor of 
such room that in every part not occupied by a joist or 
girder there shall be a layer of concrete pugging of good 
quality, or of other solid material at least 3 in. in thickness, 
finished smooth upon the upper surface and properly sup- 
ported." 

The following suggestions are worthy of consideration ; 
they are based -on the " Notes on Building Construction " 
(Kivington's) : — The dimensions of staircases and steps are 
regulated by the class of property and the purposes for which 
they are intended. The angle of ascent for a stair depends 
upon the total height to be gained between the floors, and 
the space that can be afforded in plan. The speculative 
builder will naturally be tempted to make both of these 
as small as he possibly can. The wider the step, the less the 
rise should be, as steps which are both wide and high require 
a great exertion to climb, and are consequently insanitary 
to those whose constitutions incline to weakness of heart 
and shortness of breath. Authorities differ slightly as to 
the proportion between the tread and riser. The following 
table is given in Newland's " Carpenter's and Joiner's 



100 SANITARY G0N8TBUGTI0N IN BUILDING. 

Assistant," and the subject is discussed in Adams' 
*' Building Construction'* (Cassell & Co.) : — 

Tread 6 in. Riser 8J in. 

7 ,, ,,8 






9 7 



The following rule is often adopted for steps of the dimen- 
sions required in ordinary practice : — Width of tread x height 
of riser = 60 to 65 in. The rule adopted in France, where 
they have given great attention to the subject, is as follows : — 
" Inasmuch as on the average human beings move horizontally 
2 ft. in a stride, and as the labour of rising vertically is twice 
that of moving horizontally, the width of the tread, added 
to twice the height of the riser, should be equal to 2 ft." 
The tread of a step should, however, never be less than 9 in., 
even for the commonest stair ; and the maximum height 
of a riser should never be greater than 9 in. Flights of 
stairs should, when possible, consist of not more than 
twelve or thirteen steps, after which there should be a 
landing. 

This same section of the p.d.A. Amendment Act, 1890, 
which has just been considered, after empowering Local 
Authorities to make bye-laws " with respect to the structure 
of floors, hearths, and staircases," proceeds to add, " and 
the height of rooms intended to be used for human habitation." 
The L.G.B. has not promulgated any m.b.l. on the subject, 
but in December, 1891, the year after the passing of the 
Act, the Board published a " Memorandum concerning a 
height to be appointed, under the provisions of the p.h.a. 
Amendment Act, 1890, § 23, by Sanitary Authorities, for 
rooms to be used for human habitation " ; and a bye -law 
has been drawn up by Messrs. Knight & Co. as follows : — 

No. Q. " With respect to the Height of Rooms intended 
to be used for Human Habitation. — Every person who shall 
erect a new building, and shall construct any room therein 
so that it may be used for human habitation, shall comply 
with the following requirements : If such room is not in- 
tended to be used as a sleeping- room, he shall construct 
such room so that it shall be not less in any part thereof 
than 9 ft. in height. If such room is intended to be used 



FLOORS, HEARTHS, AND STAIRCASES. 101 

as a sleeping-room, and not an attic or a room in the roof 
of such building, he shall construct such room so that it 
shall be not less in any part than 9 ft. in height. If such 
room is intended to be used as a sleeping-room, and is an 
attic or a room in the roof of such building, he shall construct 
such room so that it shall be not less in any part than 5 ft. 
in height, and so that it shall to the extent of two-thirds 
of the superficial area of the floor be of a height of not less 
than 9 ft." 

The Memorandum remarks that it will seldom or never 
be requisite to appoint by bye-law any maximum height 
for habitable rooms. Under ordinary conditions low-ceiled 
rooms are comparatively more difficult to ventilate than 
rooms of greater height ; and, as regards living-rooms, the 
fact is so far generally recognised that they are usually 
built of a sufficient height. It is more particularly in the 
case of sleeping-rooms that builders fail to act upon this 
knowledge ; and yet it is in sleeping-rooms that adequate 
height is of the greatest importance, because the occupants 
are not able during sleep to vary the conditions of air-move- 
ment through the room. 

Bye-laws on this height question, being of chief importance 
for sleeping-rooms, are of especial importance in the case 
of domestic buildings, where rooms may, in the ordinary 
course of events, be occupied during the night by a number 
of persons. The provision of adequate breathing space for 
all the occupants of a room will be materially facilitated 
or hindered, according as the height of the room is varied. 
A room may provide sufficient floor space for the wants 
of a given number of persons ; but whether this number 
of persons will have enough breathing space to keep them 
in health will depend upon the height of the room. If, 
for example, there is just enough breathing space when the 
height is 8 ft. or 9 ft., it is obvious that there will not be 
enough when the height is only 7 ft. The requisite space 
can only be obtained, in rooms of insufficient height, by 
reducing the number of persons occupying the room ; that 
is, by giving the several occupants a floor area in excess 
of what would otherwise be sufficient for them. But too 
many people reckon a room's capacity by its floor area only, 
without regard to its height, and in this way rooms of in- 



102 SANITARY CONSTRUCTION IN BUILDING, 

sufficient height operate in serious measure to foster " over- 
crowding." 

Having in view these considerations, the l.g.b. give 
notice that, all due regard being had to economy as well 
as to health, the minimum height had better be 9 ft. ; in 
some cases the Board may approve of bye-laws fixing 8J ft. 
or 8 ft. as the minimum, but they prefer 9 ft., and in no case 




Fig". 93. — Averao^ing Heinrht of Room. 

will they ever approve of a less height than 8 ft. over the 
total area of the room. 

In the case of rooms in the roof of a house, where very 
often the height of the room is not uniform, and where there 
is a much greater temptation for the builder to economise, 
there is just the same reason as in the case of other rooms 




Fig. 94.— Averaging Height of Room. 



for securing proper height for them ; the last clause of the 
above-quoted bye-law is intended to cover this, and to 
ensure the mean height of the room being not less than 
8 ft. This can be arranged with roofs of different shapes 
as shown at Figs. 93 to 95. With an attic 25 ft. wide, having 
the floor 5 ft. below the level of the eaves, and the roof pitched 
at an angle of 33°, it will suffice if the highest point of the 
ceiling is 9 f^. above the floor, which, it will be found, allows 
this height over one-half of the superficial area of the room 
(Fig. 93). When the floor is on a level with the eaves, 



FLOORS, HEARTHS, AND STAIRCASES, 103 

and the roof forms with it an angle of 38°, ashlaring 5 ft. 
in height must cut off the bottom angles, when an extreme 
height of 8 ft. 9 in. over three-fifths of the area of a roopa 
25 ft. wide will provide the minimum average over the whole 
space (Fig. 94). With a mansard — or, as it is sometimes 
called, a Dutch — roof, the angles being respectively 57° 
and 132°, with 5 -ft. ashlaring, and with a portion of the 
ceiling equal to five-sixths the floor area 8 ft. i in. in height, 
a mean height of 8 ft. over a 25- ft. room will be attained 
(Fig. 95). 

The floor area of rooms is not mentioned in any of the 
p.H.A. Many writers on sanitary engineering hold that the 
size of the room regulates itself, being according to the value 
of land, the depth of the owner's pocket, the probable in- 
come that can be obtained as rent, etc. It will, however, 
be generally admitted that the living-room of a house should 




o 1 

Fig". 95.— Averaging Height of Room. 

have sufficient cubic contents to provide for the family 
living in it ; and as the height of the storey is never excessive 
the floor area ought not to be too strictly limited. It will 
be shown later that the m.b.l. provide for a sufficiently 
wide street in front, a fair-size back yard, and an ample 
distance between the back of the house and the opposite 
property. A builder, having to leave such a large quantity 
of land unbuilt upon, is all the more tempted to reduce 
the area of the rooms within the house ; and a working 
man and his family are thus half-suffocated in a small room, 
whilst a large air-space, which they cannot enjoy, is left 
around the house. 

The size of habitable rooms no more regulates itself 
than the width of streets, the structure of walls, or the 
provision of damp-proof courses regulate themselves: The 
average number in a family is five persons, and the minimum 



104 SANITARY CONSTRUCTION IN BUILDING. 

space in a bedroom per head should be 300 cub. ft. ; taking 
the same figure for a living-room, namely, 1,500 cub. ft., 
and dividing by a minimum height of 9 ft., the floor area 
should be 106 super, ft. The minimum size for the principal 
or living-room in a house should be 144 super, ft. in area ; 
less than this is conducive to overcrowding, and injurious 
to health. 

There is one more point included in the p.h.a. Amendment 
Act, 1890, namely, with respect to " the paving of yards 
and open spaces in connection with dwelling-houses." Messrs. 
Knight & Co. have drawn up two bye-laws on this subject ; 
the first applying to houses already erected, and where the 
yards are not paved ; the second applying to the yards of 
new houses. The materials mentioned have been dis- 
cussed earlier, and it will not be necessary to go through 
them again. The bye-laws read as follows : — 

"11. The owner of every dwelling-house in connection 
with which there is any yard or open space, shall, where 
it is necessary for the prevention or remedy of insanitary 
conditions that all or part of such yard or open space shall 
be paved, forthwith cause the same to be properly paved 
with a hard, durable, and impervious pavement of flagging 
or paving bricks evenly and closely laid upon a sufficient 
bed of good concrete, mortar, or other suitable material, 
and properly jointed, or with good cement concrete, or 
with good asphalt on a proper foundation, and so sloped 
to a properly constructed channel as effectually to carry 
off all rain or waste water therefrom. 

" 12. Every person who shall erect a new dwelling-house 
shall cause not less than 150 sq. ft. of any open space pro- 
vided in connection therewith to be paved with hard, durable 
and impervious pavement of flagging or paving bricks, 
evenly and closely laid upon a sufficient bed of good con- 
crete, mortar, or other suitable material, and properly jointed, 
or with good cement concrete, or with good asphalt on a 
proper foundation, and so sloped to a properly constructed 
channel as effectually to carry away all rain and waste water 
that may fall thereon. He shall cause such paving to be 
so arranged that it shall adjoin the external wall in the rear 
or at the side of the dwelling-house, that wherever practicable 
it shall extend throughout to a distance of 10 ft. from the 



■J. ■■ 



FLOORS, HEARTHS, AND STAIRCASES. 105 

said wall, and that, subject to this last-mentioned require- 
ment, it shall extend as nearly as conveniently may be to 
the full width of the open space. For the purposes of this 
bye-law, the expression ' width ' means, in the case of paving 
in the rear, a measurement taken parallel to the rear external 
wall of tjie dwelling-house, and, in the case of paving at 
the side, a measurement taken at right angles to the side 
external wall on which such paving may abut." 



106 



CHAPTER VIII. 

AIR SPACE AND VENTILATION. 

The next subject on which a Local Authority is empowered 
(by § 157 of the p.h.a., 1875) to make bye-laws is : " (3) With 
respect to the sufficiency of the space about buildings to 
secure a free circulation of air, and with respect to the ventila- 
tion of buildings." 

It has already been mentioned that the first p.h.a. was 
the result of an inquiry, held in 1842 and subsequent years, 
into the sanitary state of large towns and populous districts. 
One of the points brought out in that inquiry, and one which 
is well known to all who live in towns, was the practice of 
building houses in courts 10 ft. or 12 ft. wide, generally 
back to back, while the entrance to each court is a tunnel 
or covered passage 3 ft. wide under the upper storeys of 
the houses in the main street. Fig. 96 gives a typical 
example of this arrangement. With a few notable exceptions, 
Sanitary Authorities in England will not allow .back-to-back 
houses to be erected, and the m.b.l., wherever adopted, 
effectually prevent this — first, by requiring a comparatively 
wide space in front ; and, secondly, by insisting upon a 
yard of a certain area at the back, and also a minimum 
distance from the opposite property at the rear of the 
house. 

The following is the m.b.l. requiring a space in front 
of new buildings : — 

M.B.L. No. 52 : " Every person who shall erect a new 
domestic Ibuilding shall provide in front of such building 
an open space, which, measured to the boundary of any 
lands or premises immediately opposite, or to the opposite 
side of any street which may not be less than 24 ft. in width 
at the point where such building may front thereon, shall, 
throughout the whole line of frontage of such building, 
extend to a distance of 24 ft. at the least ; such distance 
being measured in every case at right angles to the external 



AIR SPACE AND VENTILATION. 107 

face of any wall of such building which shall front or abut 
on such open space. Where a new domestic building may 
be intended to front on a street laid out before the confiimation 
of.theae bye-laws, and of a less width than 24 ft., the person 



who shall erect such building shall provide in front thereof 
an open space, which, measured to the opposite side of such 
street throughout the whole line of frontage of such build- 
ing, shall ext«nd to a distance equal at least to the width 



108 SANITARY CONSTRUCTION IN BUILDING. 

of such street, together with one-half of the difEerence be- 
tween such width and 24 ft. Any open space provided 
in pursuance of this bye-law shall be free from any erection 
thereon above the level of the ground, except any portico, 
porch, step, or other like projection from such building, or 
any gate, fence, or wall not exceeding 7 ft. in height. A 
person who shall make any alteration in or addition to any 
building or who shall erect any new building shall not, by 
such alteration, addition, or erection, diminish the extent 
of open space provided in pursuance of this bye-law in con- 
nection with a building, or in any other respect fail to comply 
with any provision of this bye-law." 

It will be noticed that the space in front shall extend 
24 ft. from the wall of the house ; but this is when that 
space is not used as a carriage -road, for another bye -law 
provides that every new street intended for use as a carriage - 
road shall be at the least 36 ft. wide. It is further provided 
that every street above 100 ft. long shall be constructed 
as a carriage-road, and therefore at least 36 ft. wide ; also 
that any new street not intended to be used as a carriage- 
road, and being less than 100 ft. in length, to be 24 ft. wide 
at the least. Although power is given to erect houses with 
only 24 ft. in front of them, this can only happen in the older 
parts of towns, where large houses standing in gardens are 
demolished, and the space is utilised for cottage • houses. 
In the newer parts of the town, houses will be erected 
along the sides of streets 36 ft. wide, and thus a greater 
air-space is provided than that set out in the above bye- 
law (No. 52). 

The next M.B.L. (No. 53) provides for the sufficiency of air- 
space at the rear, and reads thus : — 

M.B.L. No. 53 : " (1) Every person who shall erect a 
new domestic building shall provide in the rear of such 
building an open space exclusively belonging to such building, 
and of an aggregate extent of not less than 150 sq. ft., and 
free from any erection thereon above the level of the ground, 
except a water-closet, earth-closet, or privy, and an ashpit, 
constructed respectively in accordance with the bye-laws 
in that behalf. In the case of a domestic building not being 
a building intended and adapted to be used exclusively 
as a stable, he shall cause such open space to extend through- 



AIR SPACE AND VENTILATION. 109 

out the entire width of such building, and he shall cause the 
distance across such open space from every part of such 
building to the boundary of any lands or premises imme- 
diately in the rear of the site of such building, to be not 
less in any case than 10 ft. If the height of such building 
be 15 ft., he shall cause such distance to be 15 ft. at the 
least. If the height of such building be 25 ft., he shall cause 
such distance to be 20 ft. at the least. If the height of such 
building be 35 ft. or exceed 35 ft., he shall cause such dis- 
tance to be 25 ft. at the least. In any case where, by reason 
of the exceptional shape of the site of such building, the 
minimum distance across the open space required by this 
bye-law cannot be obtained throughout the entire width 
of such building, it shall suffice if the mean distance across 
such open space be not less than the minimum distance so 
required. 

" Provided that (1) Where it is intended to erect a new 
domestic building on a site abutting on two or more streets ; 
or (ii) where it is intended to re-erect a domestic building 
in a street laid out before the confirmation of these bye- 
laws ; and it is impracticable to comply with the 
preceding requirements of this bye-law, the said require- 
ments shall be deemed to be satisfied by the provision 
at the rear or on one side of the site other than the front 
of such building of an open space exclusively belonging 
to such building of an extent of at least 150 sq. ft., or, in 
the case of a re-erection of a domestic building, of an extent 
not less than that of any open space previously provided 
in connection with such building and in no case less than 
100 sq. ft., which shall be free from any erection thereon 
except a water-closet or earth-closet and an ashpit, and 
subject to the following conditions : — (a) The open space 
shall extend throughout at least 10 ft. of the width or 
depth of such building, and the mean distance across such 
open space, measured from the opposite part of such 
building, to the nearest boundary of any street, lands, or 
premises immediately adjoining such open space shall be 
in no case less than 10 ft. ; and (6) if the said open space 
does not abut on a street it shall be connected with a 
street by means of a passage or other similar opening so 
arranged as to be capable at all times of affording a free 



110 SANITARY CONSTRUCTION IN BUILDING. 

circulation of air between the open space and such 
street. 

" (2) (a) This bye-law shall not apply so as to require 
any open space to be provided in the rear of any domestic 
building other than a dwelling-house where such building, 
not being a stable, is appurtenant to a dwelling-house, and 
is not of a greater height than such dwelling-house, and 
abuts on the open space provided in the rear of such dwelling- 
house, and where the open space so provided is sufficient 
to comply with the requirements of this bye-law ; or where 
such building being a stable has adjoining and exclusively 
belonging to it an open space of not l6ss than 150 sq. ft. 
in extent, (h) Where any such building, not being a stable, 
is of a greater height than the dwelling-house to which it 
is appurtenant, the foregoing exemption shall not apply, 
unless the open space in the rear of such dwelling-house 
is sufficient to comply with the requirements of this bye-law 
in respect of a dwelling-house of the height of the building 
so appurtenant. 

" (3) A person who shall make any alteration in or addition 
to any building, or who shall erect any new building, shall 
not, by such alteration, addition, or erection, diminish the 
extent of open space provided in pursuance of this bye- 
law in connection with a building, or in any other respect 
fail to comply with any provision of this bye-law. 

" (4) For the purposes of this bye-law the height of a 
building shall be measured upwards from the level of the 
ground over which such open space shall extend to the level 
of half the vertical height of the roof or to the top of the 
parapet, whichever may be the higher." 

Fig. 96 shows the necessity for this regulation. The 
houses facing the two streets were apparently erected first, 
and with adequate air-space between their backs. A later 
owner then crammed as many back-to-back houses as possible 
into this open space, bringing about the state of things 
mentioned in the second paragraph of this chapter. Need- 
less to say, this area has since been cleared as insanitary. 
Much information on this subject can be obtained from a 
Report to the l.g.b. on Back-to-back Houses, by Dr. Barry 
and Mr. T. Gordon Smith, f.r.i.b.a., dated February, 1888 
(Wyman and Sons, London). 



AIB SPACE AND VENTILATION. Ill 

It is not now permissible to mass so many persons on 
the acre. On reference to Fig. 96 it will be found that 
there are forty-one houses back to back, each house (in- 
cluding its own portion of the court) occupying 30 sq. yd., and 
allowing four persons to each house, the almost incredible 
total is 564 persons per acre ; even when the number of 
occupants per house is reduced to three, there are 484 persons 
to the acre. Taking the area of the whole block and half 
the width of the adjacent streets, there are forty-one houses 
with, say, three occupants each, and twenty-four houses with, 
say, five each, or a total of 243 persons on 3,870 sq. yd., or 
304 persons per acre, which is still phenomenal. 

Mr. J. P. Williams-Freeman, writing some years back 
" On the Effect of Town Life on the General Health, with 
especial Reference to London/' said, " The average density 
of * urban * London is ninety-nine persons per acre (* sub- 
urban ' London only having twenty- two). In urban London 
the minimum density is that of the sub-district of Norwood 
in Lambeth, which is eighteen to the acre ; and the greatest 
is found in St. Andrew's, Eastern, Holborn, a sub-district 
of 33 acres, with the extraordinary density of 324 persons 
per acre. In the year 1889, a district in Ancoats, Manchester, 
32 acres in extent, and with an estimated population of 
5,654, was, according to an ' official representation ' made 
by Dr. Tatham, m.o.h., ' unfit for habitation.' The evils 
coanected with such houses, courts, and alleys, and the 
sanitary defects in each area, could not be effectually remedied 
otherwise than by an improvement scheme for the re-arrange- 
ment and reconstruction of the streets and houses within 
the area. The death-rate over the whole district at the time 
was more than fifty per 1,000 ; in the courts it exceeded 
eighty, and in one street was over ninety. This population 
works out at 176f per acre. The population in a district 
near that indicated by Fig. 96 containing 24f acres, was, 
in 1891, 5,243, or 220 per acre ; the number of houses was 
1,117, or forty -five per acre, with an average of 4f persons 
per house." 

The very smallest houses it is possible to build under 
the foregoing bye -laws, namely, those containing only one 
room downstairs, and one above, with half of a 36-ft. street 
in front and a yard of 150 sq. ft., will occupy 84 sq. yd. of 



112 SANITARY CONSTRUCTION IN BUILDING. 

land (see Fig. 97) ; this will give fifty-seven houses, or 171 
persona per acre at three per house. A house coutaining 
two rooms on the gronnd floor (see Fig. 98), with similar 
open spaces, will occupy about 100 sq. yd. of land ; this 
will equal forty-eight houses, and at four persona per house 
will- give a density of 192 persons per acre. A house con- 
taining two rooms and a acullery on the ground floor, and 
with an attic bringing it above the 25 ft. in height (see Fig. 
99), will occupy about 125 aq. yd., being thirty-nine houses 




per acre, or a density, at five per house, of 195 to the 
acre. 

As the oize of the house increases, so, proportionately, 
there are fewer houses, and consequently a smaller population, 
per acre ; but it must be remembered that in these calcu- 
lations the lungs or breathing -places of the town— that is, 
the parka and recreation grounds — have been omitted. It 
will be seen that much depends upon the arrangement of 
the buildings ; it is quite possible to house 200 persons 
per acre in accordance with the m.b.l. and with the most 
perfect sanitary arrangements ; on the other hand, it is 
possible to house only half the number per acre, and yet have 
neither a sufficiency of air-space round the buildings nor 
any sanitary arrangements. The power to enforce the 



AIR SPACE AND VENTILATION. 113 

formei is in the hands of the Sanitary Inspector, when the 
Local Authority has adopted a code of hye-laws worthy 
of the name. 

Other important provisions in bye-law No. 53 relate to 
sites adjoining two streets meeting at an acute angle, and 
to the necessity for additional open spaces where part of 
the building projects in the rear ; there is also a provision 
concerning the re-erection of buildings on the original site. 

Before taking up the m.b.l. on the ventihition of the 



inside of a dwelling, it will be desirable to devote a little 
space to the consideration of the constituents of air, the 
necessity for an adequate supply, what amount constitutes 
an adequate supply, and some simple tests for determining 
the amount of impurity there may be in the atmosphere 
of a room. 

Ventilation ia a term applied to the method by which 
a due supply of fresh air is maintained in buildings, and 
in other confined places such as mines and ships. The 
word is derived from the Latin veTilus, the wind ; and was 



114 SANITARY CONSTiiUGTION IN BUILDING. 

first used about 200 years ago by a French scientist, who 
d3voted a great deal of time, money, and skill to studying 
the principles of the science. His method of ventilation 
consisted in the propulsion of air by means of a fan, and 
the man who worked the fan was called the " ventilator.'* 
This word has since changed its meaning, and is now used 
to denote a hole through which air passes or is intended 
to pass. 

There is considerable confusion in the minds of many 
persons as to the effect on the body of hot air and foul air, 
and a word or two on this matter will not be out of place. 
Everyone knows that covering the face with a cloth will 
soon produce a feeling of heat, followed by still more dis- 
tressing symptoms ; the same feeling is experienced in an 
overcrowded rcom, and the cause is the same in both cases. 
To the heated atmosphere are attributed the lassitude, dis- 
comfort, and lowering of the vitality so famiUar to all who 
frequent overcrowded assemblies ; but in a well- ventilated 
Turkish bath, where the temperature is considerably higher, 
no such distress is felt, and this shows at once that it is not 
heat, but something else, that causes the discomfort. That 
something else is foul air, which lowers the vitdHty of the 
body until it becomes painfully sensitive to the slightly 
raised temperature of the respired air and thus gives warning 
of the danger. Many of the evils supposed to result from 
the transition from heated places of public assemblies 
' to the cold night air are due to the enfeebled condition of 
the body consequent upon the inhalation of a vitiated atmo- 
sphere rather than to the mere change of temperature. 

COMPOSITION OF AIK. 

Oxygen . . from 20*87 to 20*96 

Nitrogen „ 79*00 „ 79*00 

Carbonic acid „ '04 „ '02 

Ozone, salts of sodium, or- j 

ganic matter, ammonia, > ,, '09 „ *02 

etc j 



100*00 100*00 



AIR SPACE AND VENTILATION, 115 

Pure air may be said to consist of oxygen, nitrogen, 
aqueous vapour, carbonic acid, and small quantities of ozone, 
salts of sodium, organic matter, ammonia, etc. The pro- 
portions are varying, but the foregoing table shows the 
average in parts per 100. 

The nitrogen is unvarying in quantity, and inert in its 
quality. It supports neither life nor combustion, and one 
of its uses, if not its principal use, seems to be to dilute the 
oxygen. The oxygen is the effective agent in the air, and 
is the constituent absolutely necessary for life. The main- 
tenance of the bodily heat, energy, and the various internal 
complex processes depends on a constant supply of oxygen. 
Life, to represent the complex by the simple, may be regarded 
chemically as similar to the burning of a lamp. In the lamp 
flame the oxygen of the air combines with and converts 
the carbon and hydrogen of the oil into carbonic acid and 
water, as indicated by the following diagram : — 

Oil. Air. 



Carbon. Hydrogen. Oxygen. Nitrogen. 



Carbonic Acid, Water. Inert. 

CO2. H2O. 

In a lamp this operation goes on with such rapidity as to 
cause heat enough to make the disengaged particles of carbon 
incandescent, and so we get light. In the human body 
the process is slower, and the temperature remains at about 
98*4° F., but the essence of the process is the same, and the 
products are also mainly carbonic acid and water. With 
the exception of ozone, all the other constituents are impurities, 
and arise in various ways. They are — (a) given out by the 
lungs, the products of respiration consisting chiefly of car- 
bonic acid ; (6) thrown off from the skin through the pores. 



116 SANITARY. CONSTRUCTION IN BUILDING. 

consisting chiefly of organic matter and ammonia ; (c) the 
products of combustion, lamps, gases, fires, etc., also chiefly 
carbonic acid gas ; [d) efll via from trades ; (e) effluvia 
from sewers ; (/) effluvia from the soil ; (g) effluviia from 
unremoved putrefactive or putrefying refuse, etc., all of 
which are complex in their composition, nauseating in their 
odour, and dangerous to health. 

Ozone is a constituent of which very little is known ; 
it is conjectured to be electrified oxygen, and to be a com- 
pound molecule made up of one double and one single atom 
of oxygen (O^O). It is, however, only found where the 
air is very pure (mountains and seashores), and is absent 
in towns, except immediately after a thunderstorm, when 
the air has been cleansed and purified. 

In dealing with the subject of ventilation so far as it 
immediately concerns us, the three pollutions first mentioned 
must claim our attention — carbonic acid from the lungs, 
organic matter from the pores, and the products of com- 
bustion. 

It has been shown in the table on p. 114 that the average 
percentage of carbonic acid in town air of normal purity 
is about '04. Now the quantity of air each person requires 
must be a proportion between the utmost allowable vitiation 
and the amount of CO^ discharged into the air, plus 
the impurity already present. The utmost allowable vitiation 
must not exceed the least amount that is evident to the 
keenest sense of smell. This has been found to allow an 
added percentage of '02 of CO2 ; therefore, air with such 
added percentage is foul, and with a lower percentage is 
fresh. 

Fresh Air. Foul Air. 

Oxygen . . . . 20*91 \ average 20*89 

Nitrogen .. .. 79*00 ( of 79*00 

Carbonic Acid . . '04 f former '06 

Etceteras . . . . '05 * figures '05 



100*00 100-00 

The amount of carbonic acid expired is given by Dr. 
Parkes (" Hygiene," p. 134) as '6 cub. ft. per hour ; but 
it must be manifest that the occupation of each person 



AIB SPACE AND VENTILATION. 117 

must govern the calculations. Another authority gives the 
amount for the following persons : — 

Child '46 cub. ft. 

Woman . . 

Man during repose 

slight exertion 

ordinary work 

strong exertion 

However, '6 is a convenient figure. Expired air contains 
the following proportions : — 

Oxygen . . . . 15*91 

Nitrogen .. .. 79-00 

Carbonic Acid . . 4*70 

Etceteras . . . . '39 (chiefly organic matter). 



if >> 



•62 „ „ 

•50 „ „ 

•76 „ „ 

*92 ,, ,, 

1-50 „ „ 



100-00 



Sufl&cient air must be introduced, or ever^' person given 
sufficient space to reduce the carbonic acid by 250 per cent, 
and to make up the oxygen consumed at each respiration. 
A person standing in the open air on a calm day is exposed 
to about 32,000 cub. ft. of air passing by him per hour. It 
is impossible that he should be supplied with this amount 
in a closed space, but careful experiments by Dr. Parkes 
have shown that the best room ventilation which can be 
reasonably available will supply 3,000 cub. ft. per head 
per hour. The air will then remain absolutely without 
sensible odour, and the carbonic acid impurity will not 
exceed 6 parts in 10,000 (or '06). This is ideal ventilation. 

This experiment is borne out by the following formula 
of Dr. de Chaumont (Parkes' " Hygiene," p. 135) : — 

r 
where V = volume of air required per hour. 

R = ratio of CO^ naturally in air = '0004 per cub. ft. 

r^ = amount respired per hour = '6 cub. ft. 
and r = ratio to which r^ should be reduced = -0002 

,. -6 — -0004 -5996 ' « nno l q nnr^ X. 

V = = — ^ = 2,998 or nearly 3,000 cub. 

•0002 -0002 ^ 

ft. per hour. 



118 SANITARY GONSTBUCTION IN BUILDING. 

Therefore, in a room containing 100 cub. ft., the air should 
be changed thirty times per hour for each person ; or if 
the room contains 1,000 cub. ft., the air should be changed 
three times in the hour for each occupant. 

It might be asked why so large an amount of air is re- 
quired, considering the small amount each person actually 
inspires (15 cub. ft. or .18 cub. ft.). The necessity can best 
be illustrated by the analogy of a water supply, as given 
by Professor Jacob, somewhat as follows : " Engineers allow 
a minimum of 20 gal. a head in estimating the amount of 
water to be supplied to a town. The water is drawn from 
a tap, and having been used is discharged into a drain. The 
fouled water does not again mix with the common supply. 
But imagine a household of ten persons with the 20 gal. 
per head in one central cistern, capable of holding 200 gal., 
from which all water must be taken, and to which the fouled 
water must be returned. Imagine the abominable state of 
such cistern after a few hours' use, and it will then be easy 
to understand that nothing short of a rapid stream of many 
thousand gallons a head flowing through such cistern would 
keep the water pure. 

*' Something of this kind obtains in many village commu- 
nities in India, but in civilised countries such an arrange- 
ment would be considered inexpressibly foul ; yet a pre- 
cisely similar condition of things exists in the air-supply 
in a confined space. The air each person breathes is taken 
from a common stock, and returned with all its gaseous 
impurities, laden with moisture and heat, into the same 
common stock, which naturally enough quickly becomes 
foul. To keep the air pure these impurities must be removed 
as rapidly as they are exhaled. The prodigious amount 
of air the living body requires is not for the purpose of supply- 
ing it with oxygen, but in order so to dilute the poisonous 
substances produced by respiration that they become in- 
nocuous and free from odour." 

The products of combustion from fires generally pass 
out into the atmosphere at once by means of the chimney ; 
those of lighting are for the most part allowed to diffuse 
in the room. Coal gas when fairly purified consists 
of the following parts per 100 (Parkes' " Hygiene," 
p. 101):— 



A IB SPACE AND VENTILATION. 



119 



COMPOSITION OF COAL GAS. 



Hydrogen . . 


40- to 


45-58 


Marsh gas (carburetted hydrogen) 


35- „ 


40- 


Carbonic oxide 


3- „ 


6*60 


Olefiant gas (ethylene) . . 


3- • „ 


4- 


Acetylene 


2- „ 


3- 


Sulphuretted hydrogen 


0-29 „ 


1- 


Nitrogen 


2- „ 


2-50 


Carbonic acid 


3- „ 


3-75 


Etceteras 


•5 „ 


1- 



88*79 



j> 



107-43 



When the gas is burnt, the results ai'e as follows : — 



Hydrogen 


.. 0- 


Nitrogen . . 


.. 67- 


Water 


.. 16- 


Carbonic acid 


.. 7- 


Carbonic oxide 


.. 6- 


Etceteras 


.. 4- ^ 



I With perfect combus- 
\ tion, practically 00. 



100-00 

A cubic foot of gas when burnt up will units with 1*60 cub. ft. 
of oxygen, and produce 2 cub. ft. of carbonic acid, and f om 
-3 to -5 gr. of sulphurous acid. In other words, 1 cub. ft. 
of gas will destroy the entire oxygen of about 8 cub. ft. of 
air. An ordinary oil lamp, burning about 154 gr. per hour, 
consumes the oxygen of about 3*2 cub. ft. of air, and pro- 
duces a little more than half a cubic foot of COj. Thus a 
lamp is only about one -fourth as harmful as a gas burner 
burning only 1 cub. ft. per hour ; but most burners consume 
at least 3 cub. ft. per hour, thus producing 6 cub. ft. per 
hour of carbonic acid Calculating as before, with the 
formula — , ^ 

V = ^ ~^ 



where r^ = amount of CO.^ per burner — 
V = 6 — -0004 ^ 5-9996 
•0002 -0002 



= 29,998, or 30,000 cub. ft. 



120 SANITARY CONSTEUGTIOX IN BUILDING, 



From this may be seen what a large supply of air is necessary 
in a room where ^as bums continually. Not all rooms 
are occupied during the whole twenty -four hours, nor is the 
gas burning continually ; so that although the calculations 
are theoretical, and such ventilation is ideal, yet in practice 
2,000 cub. ft. per head, and 6,000 cub. ft. per burner, is allow- 
able, except where the nature of the work indicates that 
the body of each worker gives ofE 1 cub. ft. or more of CO2 
per hour. However, windows, doors, and other air passages 
should be opened wide as soon as the room is unoccupied, 
and the whole air of the room changed. 

CARBONIC ACID IN AIR. 





Contents— 










• 


cubic 


Cubic in. 


1 


If turbid, volumes of CO2. 


•IH 


centimetres 
















In 10,00c 


1. Per cent. 









"S 1= 


^^ 


/s/. f utmost al- 


I-H 
• CO 


450 


27-45 




6 or 


1 lowable. 


.SO 
J^ II 


350 


21-35 


o3 '*' 


7 „ 


•07 


CO u 


300 


18-30 




8 „ 


•08 


II § 






II 

• 








250 


15-25 


^ 
oB 


10 „ 


•10 




200 


12-20 


g 

I-H ;> 


12 „ 


-12 


Cent 
Cubi 


100 1 

1 


610 




10 ,, 


•1 fi / produces 
1 headache. 



The following is one method of testing and roughly ascer- 
taining the amount of carbonic acid in the air of a room, 
and is given by the late Professor Jacob in his " Notes on 
Ventilation and Warming," p. 13 : " Six stoppered bottles 
are taken, containing respectively 450, 350, 300, 250, 200, 
and 100 cub. centimetres. These are filled, by means of a 
small hand-ball syringe, with the air of the room to be tested. 
A glass tube or pipette, holding exactly 15 cub; cm., is then 
filled with clear, transparent lime-water and emptied into 
the smallest bottle, which is then shaken. If the fluid be- 
comes turbid, the amount of carbonic acid will be at least 
16 parts in 10,000. If no turbidity occurs, repeat the opera- 



AIR SPACE AND VENTILATION. 121 

tion with the next largest bottle. Turbidity will here indicate 
12 parts. In similar fashion, turbidity in the 250 c.c. bottle 
indicates 10 parts CO^ ; in the 300 c.c. bottle, 8 parts ; 
in the 350 c.c. bottle, 7 parts ; and in the 450 c.c. bottle, 
less than 6 parts. To judge of the turbidity, mark a piece 
of paper with a lead-pencil, and gum it to the bottle with 
the marked side next the glass i If there be turbidity, the 
mark will be invisible. The foregoing shows these figures 
in tabular form. 

§ 157 of the P.H.A., 1875, which is still being dealt with, 
allows Local Authorities to make bye-laws " with respect 
to the ventilation of buildings " ; and the l.g.b. has drawn 
up M.B.L. on the subject. It must be confessed that they 
deal very tenderly with it, not requiring anything very 
extravagant or complicated, and trusting a good deal to the 
crevices of windows and doors, and the flues of fire-places. 

The first m.b.l. on the subject reads as follows : — 

M.B.L. No. 54 : " Every person who shall erect a new 
domestic building shall construct in the wall of each storey 
of such building which shall immediately front or abut on 
such open spaces as, in pursuance of the bye-laws in that 
behalf, shall be provided in connection with such building, 
a sufficient number of suitable windows, in such a manner 
and in such a position that each of such windows shall afford 
effectual means of ventilation by direct communication with 
the external air." 

The two preceding clauses (m.b.l. No. 52 and No. 53) 
provided for a minimum amount of open space to be left 
in the front and at the rear of every new domestic building. 
No. 54 provides that the windows shall overlook these open 
spaces, so as to secure reasonable means for ventilation. A 
later bye-law provides for the size of the windows and the 
area of the portion that must be made to open. The ventila- 
tion of the space below the floor is dealt with in m.b.l. No. 
55, which has already been quoted (see p. 31). 

Wherever the lowest storey of a house has a boarded 
floor, it is absolutely necessary to provide ample means 
of ventilation to the space below the floor ; for, unless a 
current of air can pass constantly and freely between the 
wood joists and the surface of the concrete or asphalt that 
is laid over the surface of the ground beneath the house in 



122 SANITARY CONSTRUCTION IN BUILDING. 

accordance with m.b.l. No. 11 (see p. 20), it is almost certain 
that dry-rot will attack the woodwork, and the floor will 
fall to pieces in a comparatively short time. 

It has already been mentioned that some towns have 
not adopted m.b.l. No. 11, and others have added " where 
the dampness of the ground renders it necessary " ; as though 
the " concrete bed " were to protect against subsoil water 
only, and not against ground air also ! In these unfortunate 
towns there ought to be at least 9 in. between the underside 
of the joists and the surface of the ground. 

Fig. 13 (see p. 31) shows a space of 18 in., ventilated 
by large air-grids, and a flue running up alongside the fire- 
place of the room above, and acting as an exhaust shaft. 
Little is yet known as to dry -rot ; it is certain, however, 
that closed-in spaces under floors are generally attacked, 
more especially when ground air finds admittance. It is 
surmised that the spores or seeds of dry rot floating in the 
air are breathed into the lungs, and tend possibly to induce 
the growth of dangerous bacteria, bacilli, and micrococci 
in the system. 

The next m.b.l. returns to the windows of rooms, and 
reads thus : — 

M.B.L. No. 56 : " Every person who shall erect a new 
building shall construct in every habitable room of such 
building one window, at the least, opening directly into the 
external air, and he shall cause the total area of such window, 
or, if there be more than one, of the several windows, clear 
of the sash-frames, to be equal at the least to one-tenth 
of the floor area of such room. Such person shall alsb con- 
struct every such window so that one-half, at the least, may 
be opened, and so that the opening may extend in every 
case to the top of the window." 

The necessity for a window being of ample size is well 
understood. It has been proved that sunlight, or at least 
broad daylight, is necessary to maintain health, and, in 
measuring, the glass area should be taken. It will be observed 
that the window must open *' directly into the external air," 
and that a window opening into the interior of a building 
(a " borrowed " light) will not be in accordance with the 
regulation. No particular position for the window is men- 
tioned ; but it should be arranged so that the top of the 



AIR SPACE AND VENTILATION. 123 

window is near the ceiling. Neither is any particular shape 
of window required, but it must be constructed so that one 
half at least may be opened, and the opening must extend 
to the top of the window ; provided these conditions are 
observed, the window may be a sash-window double-hung, 
a French casement, a Yorkshire light (one half sliding horizon- 
tally in front of the other half), or a sash-window hung on 
pivots or hinges. It has been found by experiment that 
an ordinary window is so constructed as to admit through 
its crevices and chinks 8 cub. ft. of air per minute, even 
when closed. 

An alternative clause (No. 56a), prescribing the details 
of the ventilating arrangements, is also given, to enable the 
Local Authority to deal more satisfactorily with the subject 
in those cases where m.b.l. No. 56 is deemed to be inadequate. 

The ventilation of staircases is dealt with in a supple- 
mentary clause which reads as follows : — 

No. 56b : " Every person who shall erect a new building 
constructed or intended or adapted to be occupied by more 
than two families in separate tenements shall cause the 
principal staircase to be used by the several families in common 
to be adequately ventilated upon every storey above the 
ground storey, such ventilation to be provided except where 
such staircase is open to the external air by means of win- 
dows or skylights opening directly into the external air, and 
he shall cause the total area of such windows or skylights 
upon every storey clear of the sash frames to be equal at 
the least to one-eighth of the area on plan of such principal 
staircase. He shall cause such staircase to be provided 
with a sufficient handrail properly and securely iixed." 

The next m.b.l. relates to the ventilation of rooms with- 
out fireplaces : — 

M.B.L. No. 57 : " Every person who shall erect a new 
domestic building shall cause every habitable room of such 
building which is without a fireplace, and a flue properly 
constructed and properly connected with such fireplace, to 
be provided with special and adequate means of ventilation 
by a sufficient aperture or air shaft which shall provide an 
unobstructed sectional area of 100 sq. in. at the least." 

This provision for an aperture of 100 sq. in. is without 
reference to the size of the room. It will presently be shown 



124 SANITARY CONSTRUCTION IN BUILDING, 

by calculation that this air opening should be 1 sq. in. in 
area for each 60 cub. ft. of space in the room, and some 
towns have inserted this figure in their bye-laws, with the 
approval of the l.g.b. It will also be shown what quantity 
of air is drawn out of a room by a chimney. It is apparent, 
however, that a little roam, 8 ft. by 8 ft. by 8 ft., over a 
scullery, with one occupant, would have excessive ventilation 
through a 10-in. by 10-in. ventilator ; whilst in a large attic, 
with three or four servants sleeping in it, the stipulated 
outlet might be ridiculously small. In Fig. 100 is a sketch 
of a ventilator adequate for the purpose. An opening into 
a flue may be provided, but it must be observed that the 
area of the opening is to be 100 in., and that an ordinary 
grating 10 in. by 10 in. will not sufl&ce, as the bars will obstruct 
nearly one-half of the opening. 

The next m.b.l. refers to public buildings only. 

M.B.L. No. 58 : " Every person who shall erect a new 
public building shall cause such building to be provided 
with adequate means of ventilation." 

There is not the slightest indication as to the intent 
and meaning of the word " adequate " ; but the question 
of ventilating public buildings is so very wide, and depends 
upon so many varied conditions, that it is perhaps impossible 
to draw up a bye -law in any other terms. 

Figures have already been given (see p. 117) to show 
that each person requires 3,000 cub. ft. of air per hour ; 
but that was ideal ventilation. The sanitary inspector may 
aim at this, but much of his work hes at the antipodes of 
the ideal. A little guidance is obtained from other publica- 
tions of the L.G.B. On looking at their requirements for 
common lodging-houses, it will be found that the secretary 
of the Board, in 1877, wrote : " In rooms of ordinary con- 
struction to be used for sleeping, where there are the usual 
means of ventilation by windows and chimneys, about 300 
cub. ft. will be a proper standard of space to secure to each 
person ; but in many rooms it will be right to appoint a 
larger space, and this can only be determined on inspection 
of the particular room." 

In the Factory and Workshop Act, 1901, it was enacted 
that in a factory there should be at least 250 cub. ft. for 
each person in the daytime, and 400 cub. ft. at night. Persons 



AIR SPACE AND VENTILATION, 



125 



awake can regulate their air-supply when the air feels stuffy, 
but persons asleep are unable to do so ; therefore 300 cub. ft. 
may be considered as the irreducible minimum of air-space 
for sleeping-rooms. ' 

A practice in force in Glasgow, which is worthy of being 
adopted throughout the country, may be mentioned here. 
In those quarters of the city where overcrowding is likely 
to ociDur, a ticket is placed on the door stating the ascer- 
tained cubic contents, and stating also the maximum number 
of occupants that should be allowed to sleep in the room. 
The police officer or sanitary inspector is thus able to detect 




SB 



Fig. 100. — Ventilator through Ceiling and Roof. 



overcrowding, and the tenant of the house or room is unable 
to plead ignorance of the law when found to be exceeding 
the limit. 

While it is by no means difficult to prove that the funda- 
mental principles of the science of ventilation are precise 
and simple, yet the various methods of appljdng these princi- 
ples, and of securing a constant supply of fresh air, are legion. 
The ventilation expert is apt to declare that there is only 
one sure and certain method of ventilation, namely, his own, 
that all others are failures in practice, and that the systems 
recommended by other specialists are sure to be inefficient 
and useless. 

Before dealing with the various methods of securing 
ventilation, the following three points must be mentioned, 
but there is no need to consider the reasons which govern 
them; or the experiments which determined them. 

(1) Temperature. — In ventilating a room, the openings 
should be sufficiently large to provide for summer ventilation ; 
and not so large as to make it impossible to keep the room 



126 SANITARY CONSTRUCTION IN BUILDING. 

warm during winter. To be comfortable, ■ the temperature 
should not be lower than 48°, and not higher than 60° F., 
the mean being 57° F. This will, of course, vary with occu- 
pations, constitutions, external temperature, and the direction 
and force of the wind. 

(2) Sj>eed of Incoming Air. — The speed at which air may 
travel without being felt as a draught is 5 ft. per second. 
Any openings provided for incoming air must be sufficiently 
large for the whole supply to enter at a rate of 5 ft. per second 
or less. 

(3) Times of Change per Hour. — The organic matter 
discharged from the skin and the lungs was mentioned among 
the impuritie:. The amount has never been precisely deter- 
mined, nor is it possible to estimate it correctly. It is this 
which imparts to badly ventilated rooms the close, stuffy, 
foetid odour, thus differing from the CO., which is inodorous. 
This organic matter diffuses slowly, and specialists in ventila- 
tion agree that the whole of the air in a room should be 
entirely changed three times in the course of an hour. Even 
in winter, when the external air is below freezing point, it 
should be changed three times every two hours. 

The ideal current of moving air would be one that is 
symmetrical in its sectional area with one superficies of the 
apartment, passing gently and equably through the cubical 
space until it quits the room at the opposite superficies ; 
and, although such an ideal is unattainable, the attempt 
should be made to reach as close an approximation thereto 
as possible. It is proposed now to discuss the leading sys- 
tems, their principles, advantages, and disadvantages, with- 
out reference to the inlets, outlets, cowls, etc., of different 
patentees. 

There is, first, what is called the natural system, where 
an opening at the top of the room lets out the foul air, and 
an opening lower down admits the fresh air (see Fig. 101). 
There is, second, what is called mechanical or forced ven- 
tilation, on the plenum or exhaust system. And there is 
artificial ventilation of various sorts : inlet openings at the 
top, outlet at the bottom of the room, or both at the top, 
etc. 

Natural ventilation consists in providing an opening in 
or near the ceiling for the outlet of foul air, and an opening 



AIR SPACE AND VENTILATION. 127 

at a lower level for the inlet of fresh air. The efficiency of 
this plan is proved scientifically, and is based upon the fact 
that heat expands and cold contracts. To this natural law 
air is no exception. Foul air is generally warmed to some 
extent, and then rises to and passes out by the opening at 
the higher level, its place being taken by cooler air entering 
at the lower of the two openings. Let it be noted here 
that, in order to ventilate, there must be two openings at 
the least, one to act as an inlet, the other as an outlet. The 
effectiveness of this natural ventilation depends entirely on 
the difference of temperature between the external air and 
the internal air, and it will at once be apparent that this 
system may be very effective in winter, and fail absolutely 
in summer. 

Air dilates or expands ^ J^ of its volume for each degree 
of FaTirenheit that its temperature is raised (Parkes, p. 145). 
Consequently, its weight is reduced in the same proportion, 
and the lighter air is thus forced to the upper part of the 
room by the greater weight of the cooler air — just in the same 
way that a bladder of air, submerged in a pond, will be forced 
to the top by the greater weight of the surrounding water, 
immediately the restraining force is removed. If an opening 
13 made in the upper part of a room, the warmer or lighter 
air passes through, forced through by cooler and heavier 
air coming into the room through openings at a lower level. 
As the fresh air is in its turn heated, the movement is kept 
up in a constant stream, cold air entering by one set of orifices, 
and hot air escaping by another. 

It has already been said that ventilation is an exact 
science, and th&t its results are arrived at by calculation. 
It wiU be well to examine the method of arriving at the 
quantity of air which passes through an outlet shaft. Parkes 
writes : " The mode most generally used is based on two 
well-known laws — first, that the velocity in feet per second 
of falling bodies is equal to (nearly) eight times the square 
root of the height through which they have fallen ; and, 
secondly, that fluids pass through an orifice in a partition 
with a velocity equal to that which a body would attain in 
falling through a height equal to the difference in depth 
of the fluid on the two sides of the partition." 

This is frequently called the rule of Montgolfier. The 



128 SANITARY CONSTRUCTION IN BUILDING. 



formula is V = -s/2 ^ H ; g being the acceleration of velocity 
in each second of time, namely, 32*18 ft., and H the height 
of the descent. (See Fig. 101.) 

" The pressure of air upon any surface," he continues, 
" may be represented by the weight of a column of air of 
uniform density of a certain height. Thus the pressure of 
the atmosphere at the surface of the earth is about 14 lb. 
on the square inch, and this would be the weight of a column 
of air of about five miles high. Air, therefore, rushes into 
a vacuum with a velocity equal to that which a heavy body 
would acquire in falling from a height of five miles — ^namely, 
1,339 ft. per second. But if, instead of rushing into a vacuum, 
it rushes into a chamber in which the air has less pressure 
than outside, its velocity will be that due to a height which 
represents the difference of pressure of outside and inside. . . . 




Fig. 101. — Natural System of Ventilation. 



" Air is dilated 1 part in 491 of its volume for every degree 
Fahrenheit that ts temperature is raised ; consequently 
the difference of pressure outside and inside will be as follows : 
The height from the aperture at which the air enters to that 
from which it escapes, multiplied by the difference of temper- 
ature between outside and inside, and divided by 491. If 
the height be 20 ft., and the difference of temperature 15°, 
we have the height to produce velocity of inflowing current 

(or H) = ^^^^ = 0-61 ft. : and V = Sv/'Gl = 8 x -781 

= 6-248. 

" This, however, is the theoretical velocity In practice 
an allowance must be made for friction of one quarter, one- 
third, or even one-half, according to circumstances. The 
diminution of velocity from friction is in proportion to the 



AIB SPACE AND VENTILATION. 129 

length of the tube, and is inversely as the diameter. Right 
angles greatly increase the friction. The friction also in- 
creases as the square of the velocity. The deduction of one- 
quarte: would leave 4*686 lin. ft. per second as the actual 
velocity. If this be multiplied by the area of the opening 
in feet, . . . the amount of air is expressed in cubic feet 
per second, and multiplied by QO will give the amount per 
minute. . . As the action increases with the difEerence 
in temperature, it is most powerful in winter, when rooms 
are artificially warmed, and is least so, or is quite arrested 
in summer, . . . when the internal and external temper- 
atures are identical." (" Hygiene," p. 146.) 

In providing inlet and outlet openings while taking care 
not to make them too small, it should also be remembered 
that a small chink round each door and round each window 
will amount to an appreciable area — at least, in most of our 
houses — and that when the fire is lit the chimney flue carries 
away from 200 cub. ft. to 1,000 cub. ft. per minute. The 
following calculation will serve to show the reason why six 
people in a room, with the gases lit, do not suifocate : — 

6 persons @ 2,000 cub. ft, each per hour = 12,000 
3 gaslights @ 6,000 „ „ = 18,000 

30,000 



Fireplace 60 minutes at 500 cub. ft. = 30,000 

The room certainly gets very warm, but generally because 
the inlets are inadequate. As a rule, it is found that if an, 
inlet has been provided, it has been blocked because of a 
draught. The real- cure of the draught would have been 
to make the inlet larger. A draught was felt because the 
inlet was contracted, and the air had to pass in at a quicker 
rate than 5 ft. per second. It is a good plan to provide 
several inlets, or there is a danger of the incoming air taking 
the shortest cut to the outlet and leaving the general body 
of the air in the room stagnant (see Fig. 102). This has 
been proved to be the case on several occasions. 

It has been found by experiment that the best level for 
inlet openings is about 5 ft. or 6 ft. from the floor. They 
may be provided in many ways — (a) an opening hidden by 



130 SANITARY CONSTRUCTION IN BUILDING. 

the architrave of the door, as in Fig. 103 ; (6) a number of 
holes bored in the meeting bars of the window, as in Fig. 104 ; 
(c) a strip of wood placed on the window sill, and the window 




Figr. 102. 




Fiof. 103. 





Fig 104. 



Fi?. 105. 

Fig. 102.— Air Current Direct from Inlet to Outlet. Fig. 103.— Air 
Inlet over Lintel of Door. Fig. 104.— Air Holes Pierced through 
Window Bars. Fig. 105.— Air Inlet at Window Bars. 



shut down upon it, leaving an opening between the meeting 
bars, as in Fig. 105 ; {d) a series of Tobin tubes in different 
comers of the room, and connected to the fresh air (see 
Fig. 106) ; (e) a series of Sheringham valve inlets (see Fig. 



AIB SPACE AND VENTILATION. 



131 



107), For domestic purposes it will generally be {ound 
that t^e chimney forms an ample outlet If another outlet 
is required, a grating in the centre of the ceiling, comiected 
with a tube running between the joista and taken into the' 
open air, as in Fig. 108, will be found t« meet the case. A 



Fig 106.— Tobin Tuba Inlet. Fig, 107.— Shecingbam Inlet. 

mica flap, or other provision, to prevent down-draught when 
the wind blows directly against that wall, will be necessary. 
As already stated, this form of ventilation, the natural, is 
only effective in the winter season, when there is a marked 
difference between the internal and the external temperature. 
The forced or mechanical ventilation is of two kinds, one 




Vent Tube from Centre of Oilin!". 



being the plenum and the other the vacuum or exhaust 
principle. Mechanical means of some sort a;e resorted to 
in order to keep the air in motion, either fans (see Fig. lOW) 
or blowers, or fires, or a combination of these. In plenum 
ventilation the propulsive force is applied to the incoming 



132 SANITARY CONSTRUCTION IN BUILDING. 

air and the apartmeat filled — hence the name, which is a 
Latin word meaning hilt. Outlete are provided at convenient 
places, and the foul air is driven out by the air forced in. 
" The advantages of .this method are its certainty and 
the ease with which the amount thrown in can be altered. 
The stream of air can be taken from any point, and can, 
if necessary, be washed by passing through a thin iilm ol 
water, or filtered through a thin screen of moistened cotton, 
and can be warmed or cooled at pleasure. The disadvantages 
are the cost, the danger of the engine breaking down, and 
some difficulties in distiibution. If the air ent«rs through 
small openings at high velocity, it will make itfi way to the 



Fie;. 103.— Blackmaa Air Propeller. 

outlets without mixing. The method requires, therefore, 
great attention in detail." (Parkes' "Hygiene," pp. 161-2.) 
The exhaust, or extraction, or vacuum principle is the 
converse of the plenum. The propulsive force is applied 
to the outgoing air. This may be done in several ways. 
Thus a fan may be used ; but in such case there are the 
disadvantages of expense and of probable breakdown of 
the engine. A steam jet may be used ; this also is expensive, 
and unless great care is taken it is noisy. A fire at the loot 
of a tower may be adopted, but here again the cost of main- 
taining the fire has to be met, as well as other disadvantages, 
(a) There is the inequality of the draught, as it is almost 
impossible to keep the fire at a constant height {Parkes, 
p. 159) ; (6) the inequality of movemei|t from diflerent 



AIB SPAOi] AND VENTILATION. 133 

rooms — the nearer ones will have the air changed several 
times in an hour, those at a distance may hardly feel the 
influence ; (c) if the shaft is large, there may be no move- 
ment in the air of the rooms, but a down and up current 
circulating in the shaft itself (see Fig. 110) ; (d) the possi- 
bility of reflux of smoke from the shaft to the rooms ; (e) 
" the impossibility of properly controlling the places where 
fresh air enters — it will flow in from all sides, and possibly 
from places where it is impure, as from water-closets, etc. 
Air is so mobile that, .with every care, it is difficult to bring 
it under complete control — it will always press in and out 
at the point of least resistance " (Parkes, p. 159). For these 
reasons it will be seen that the plenum system is more likely 
to be a success than the exhaust system in all cases where 
natural ventilation is found to be inadequate. 



II 






Fig. 110. — Down and Up Currents in Large Shafts. 

Artificial ventilation covers those systems where both 
outlet and inlet are at the top and close together ; or where 
the outlet is at floor level, and other eccentricities of the 
same sort. It has been proposed to put the two openings 
side by side (Fig. Ill), or the one round the other (Fig. 112). 
The great objection in these cases is that the incoming air 
must to some extent cool the foul air, and either cause it 
to fall back into the apartment or to pass out much more 
slowly than would otherwise be the case. The reason advanced 
for putting the outlet at the floor level is that carbonic acid 
gas, being heavier than common air, will sink to the ground.. 
This is theoretically true ; COj in bulk is heavier than air 
when both are at the same temperature. But in dealing 
with room ventilation it will be found that the COg is mixed 
with the air of the room, that it is given off from the body 
at nearly 97°, and from the gas flame at a very much higher 



134 SANITARY CONSTRUCTION IN BUILDING. 



temperature. Hence the COg rises to the ceiling, and to 
cool it there by a current of fresh cold air and send it down 



%1\ 





Fig. 111.— Top Ventilation with 
Two Tubes. 



Fig. 112.— Top Ventilation with 
Concentric Tubes. 



to the floor for extraction is to re-contaminate the atmosphere 
of the room. 

The following method of testing and ascertaining roughly 
the amount of carbonic acid (COj) in the air of a room is 
given by the late Professor Jacob in his " Notes on Ventila- 
tion and Warming " : — " Six stoppered bottles are taken, 
containing respectively 450, 350, 300, 250, 200, and 100 
cubic centimetres. These are filled, by means of a small 
hand-ball syringe, with the air of the room which has to be 
tested. A glass tube or pipette, holding exactly 15 cubic 
centimetres, is then filled with clear transparent lime water, 
and emptied into the smallest bottle, which is then shaken. 
If the fluid becomes turbid, the amount of carbonic acid will 
be at least 16 parts in 10,000. If no turbidity occurs, repeat 
the operation with the next largest bottle. Turbidity will here 
indicate 12 parts. In similar fashion, turbidity in the 250- 
c.c. bottle indicates 10 parts CO3 ; in the 300-c.c. bottle, 
8 parts ; in the 350-c.c. bottle, 7 parts ; and in the 
450-c.c. bottle, less than 6 parts. To judge of the turbidity, 
mark a piece of paper with a lead pencil, and gum it 
on to the bottle with the pencil mark inside. If there be 
turbidity, the mark will be invisible." Fifteen cubic centi- 
metres == '915 cub. in., and 100 c.c. - 6'10 cub. in. 

Other imparities in the atmosphere are carbonic oxide — 
a product of imperfect combustion in coke stoves ; sulphu- 
retted hydrogen and Sulphurous or sulphuric acid gas, from 
the burning of badly purified coal gas, etc. Sulphuretted 
hydrogen may be recognised by the i)lackening of silver 



Ain SPACE AND VENTILATION. 135 

plate, by the leather bindings of books falling to pieces, etc. 
The testing of the air for these impurities is a more com- 
plicated process, and the better plan is to fill a large glass 
bottle (to hold about a gallon) with the air of the room, and 
submit to a chemist. 

To ascertain the direction of the air currents in a room, 
long filaments of the finest silk, from 6 in. to 12 in. in length, 
should be attached to the ceiling at different points ; thin 
rods reaching from floor to ceiling should be erected at different 
parts of the room, and similar rods placed horizontally at 
different levels ; to these rods the filaments should likewise 
be attached. The directions assumed by these filaments 
will indicate both the direction and the force of the moving 
currents. Smoke has also been used, but the results are 
somewhat fallacious, as the smoke, when warm, rises and 
moves independently of the general air currents. If a smoke 
test is desired, the best apparatus consists of a sponge filled 
with muriatic acid suspended over a small basin of ammonia. 
In this case the fumes have no heat. For ascertaining the 
direction of the air currents in a large chamber, Mr. Sugg 
made use of small air balloons. — H. G. Whyatt. 

Some of the above tests are open to certain objections; 
For example, to test by chemical analysis is both a tedious 
and a costly process, and Professor Jacob'^ method requires 
much practice and patience, and a multiplicity of utensils. 
More convenient for general use, probably, is Dr. Scurfield's 
ventilation indicator, which shows quickly and accurately 
the amount of carbonic acid in any sample of air that is 
tested. It is made by J. Defries & Son, Ltd. The usual 
plan is to obtain first a standard of purity by testing a sample 
of what may be considered normally pure air, the test being 
made out of doors at a distance from any building. After- 
wards the air of any number of rooms may be tested, and 
the result compared with the standard. When ready for 
use, the apparatus consists of an aspirator filled with water 
and supplied with a gauge, surrounded by a number of tubes, 
each of which can in turn be connected with the aspirator. 
These tubes all contain exactly the same quantity of baryta 
and phenolphthaleine, a pink solution which is deprived 
of its colour when brought into contact with carbonic acid. 
The air to be tested is passed through this solution, which 



136 SANITARY CONSTRUCTION IN BUILDING, 

loses its colour quickly or slowly, according to the amount 
of carbonic acid in the air. The quantity of air that has 
been tested is shown by the amount of water — recorded on 
a gauge — that has run ofi from the aspirator ; so that, in 
testing two samples of air, if to decolorise the first tube 1*8 
cans of air (represented by so much water) are required 
(sample 1), and to decolorise the second tube 1*2 cans are 
required (sample 2), the amount of carbonic acid in sample 1 
is to sample 2 as 1*8 is to 1*2 ; in other words, sample 2 
contains half as much again of carbonic acid as sample 1. 
To take another example : if for the standard test the gauge 
shows 9, and the first room tested shows 4*5, the air in the 
room contains twice as much carbonic acid as the outside air. 
The manner of using Dr. Scurfield's apparatus is as follows : 
Having filled the aspirator with water, and the tubes with 
the pink solution, the aspirator is connected with one of the 
tubes, the cock at the bottom of the gauge is opened, and 
air bubbles through the tube and into the aspirator, the 
water flowing through the gauge into the can below. Opinions 
differ as to the excess of carbonic acid allowable in the air 
of a room ; it should not be more than twice the amount 
contained in normally pure air ; should the apparatus register 
more than this, the ventilation is defective. Forty minims 
of the baryta solution and 60 minims of the phenolphthaleine 
solution added to 1 pt. of distilled water make a solution of 
sufficiently deep colour. The cost of the drugs is not ex- 
cessive, and the decolorised solution can, by adding a small 
quantity of baryta, be used over again many times. 



137 



CHAPTER IX. 

A TYPICAL DWELLING. 

In this chapter it is proposed to describe a type of house 
suitable for a working man who, being of a thrifty disposition, 
is systematically saving part of his earnings with the object 
of buying or building a house for himself. 

Choice of Site. — The rich man builds where he will, the 
poor man where he can. In the neighbourhood of towns the 
sites available are very limited both in number and in position ; 
very often in a street only one plot of lani is unoccupied. 
Before deciding upon this plot, careful inquiries should be 
made with the object of ascertaining why it has been left so 
long vacant ; it may be found that a sewer runs under the 
land, and the local authority refuse their consent to its being 
built over ; or that a neighbour has acquired rights of light ; 
or that the subsoil is unfit to build upon ; or that it is an 
old pit filled with foul refuse. If no defect can be found, 
and if the soil is clean and dry, if the land is large enough to 
provide the air-space required by the building regulations 
or bye-laws, and if the price is reasonable, then the working 
man may proceed with the purchase of the land. In the 
country there is a larger choice and the land is cheaper ; so 
that it is possible to secure a far greater area of land at a 
less price than would have to be paid for a small plot in a town. 
It is a question to be decided by each man for himself whether 
fresh air and a piece of garden ground are worth more than 
the cost of travelling and the time occupied in travelling ; 
or whether proximity to work overbalances the extra cost 
of living and the absence of country air. The site of the 
house, wherever it is situated, should be clean and dry ; 
sand or gravel form the best subsoil, clay is inferior. In 
some districts a bed of concrete covering the whole site of 
the house is insisted upon by the local authorities ; in others 
it has to be constructed only when the nature of the site 
requires it. If the ground has been tipped with foul material, 



138 SANITARY CONSTEVCTION IN BUILDING, 

it is illegal to build upon it, by the Public Health Acts Amend- 
ment Act, 1890, until the foul matter has been removed or 
rendered innocuous. If the site has been tipped with clean 
material, it is desirable to cover it with concrete in any case. 
The question of soils and sites is discussed in Chapter II. 

Aspect. — The aspect of the living-rooms of a house affects 
the health of the occupants very greatly. It is now a trite 
saying that " the doctor comes to those places which the sun 
does not visit " ; and it is an established fact that many of 
the microbes which are the cause of disease are killed bv sun- 
light. Hence, where possible, houses should be so arranged 
that the sun may shin§ into all the rooms during some portion 
of the day ; and the rooms should be so planned as to obtain 
the greatest proportion of sunshine during the times they are 



NORTH. 



NORTH. 



*ve«T 




EAST 



AEST 




EA.8T 



SOUTH 



SOUTH 



Pig. 1 1 3. — House Planned Parallel Fig.l 14. — House Planned Diagonal 
with the Compass Points. with the Compass Points. 



occupied. In the case of villas standing in their own grounds 
it is an easy matter to place the morning-room so as to obtain 
the morning sun, that is, on the easterly side of the house ; 
and the dining-room, which is most used during the evening, 
so as to catch the western sun. But in the case of working 
men's dwellings it becomes more difficult ; still, it is not 
impossible. 

It will be seen, from Fig. 113, that if a house is planned 
with its external walls towards the cardinal points of the 
compass, the north side will never receive the direct rays 
of the sun ; whilst if the liouse is Set diagonally, as in Fig. 114, 
the sun will shine into every room during some portion of the 
day. In the country, where land is cheap, it will be possible 
for even a working man's house to be thus arranged, and the 
blessings of sunlight will not be prohibited. In the town, 
where houses are built in rows, if the streets are laid out north 
and south the sun will shine into the windows on the east 



A TYPICAL DWELLING. 



139 



side in the morniDg, and on the west side in the evenings ; 
and to ensure the best result the hving-room should be arranged 
on the west side ot the row. The plansof the houses will thus vary 
on each side of the street; onthe east side oi the street the living- 
room will be placed at the front, and on the west side of the 
street at the back ; and by this arrangement the evening 



Fig. 115.— Street Planned North and South. 

sun will shine into the living-room when the greater part of 
the family are at home (see Fig. 115). If the streets are 
laid out in the opposite direction, that is, ea.st and west, 
the aame result obtains as was pointed out in Fig. 113 ; the 
north side of each row never receives the sunshine and will 
be damp, moss grown and unhealthv (see Fig 116). In 



^H 



Fig 116 —Street Planned Eitat and 'West 

laying out an estate for dwelhngs whether for the working 
or for the higher classes east ind west streets should be 
avoided ; if unfortunatelj this is impossible the hving-Toom 
should always le placed towards the south 

Accommodatt m — A few w(. rds as to the minimum accom- 
modation that should be provided in a working man s bouse 



140 SANITARY CONSTRUCTION IN BUILDING. 



before considering typical plans. It will be admitted that 
most houses have an additional room beyond those apparently 
provided, namely, room for improvement ; and whilst 
specialists try on the one hand to design cheap houses, on 
the other hand they are trying to introduce improvements 
and conveniences into the houses of the working man which 





1^ 14 4- - — -^ 

Fiff. 117.— Ground Plan of 
14 -ft. 4^-in. House. 



Fig 118.— First Floor Plan 
of Fig. 117. 



a few years ago were supposed to be entirely out of his reach, 
and by these and other means to increase everywhere the 
amenities of life. 

In a small house, the most important object to be attained 
is a good-sized living-room ; one large enough to contain 
the whole family without crowding after the labours of the 
day. There should be a small pantry to allow for the storage 
of food in such a position that the food may not be contam- 
inated by foul odours or other matters. Where possible a 



A TYPICAL DWELLING, 



141 



wash-house or wash-cellar should be constructed so as to 
keep the steam and smell out of the house. There should be 
three bedrooms, and this is an easier matter than may be 
thought possible, as will be seen from the accompanying 
Figs. 118 and 120. The advantages of three rooms rather 
than two are many. When a family is growing up, there 





rtKSMT 



Fig. 119.— Ground Plan of 
16-f t. 9-in. House. 



Fig. 120.— First Floor Plan of 
Fig. 119. 



comes a time when the two sexes should sleep in separate 
rooms ; or an occasion may arrive when a visitor has to be 
entertained, or a fever case isolated, and with three rooms 
these are easily arranged. No more space is required for 
three rooms than two ; the only difference is the space occu- 
pied by the wall ; and the additional cost is only the cost 
of a studded wall, and an additional fireplace or ventilator. 
The only case where a working man should build himself a 
house with only two bedrooms is that of an old couple whose 



142 SANITARY CONSTRUCTION IN BUILDING. 

family have gone to live in homes of their own, for it is 're- 
markable that when a working man builds a house for himself 
(or buys one) he never removes, however large his family 
becomes. Where possible a bathroom should be arranged, 
though this is not held to be necessary where public ba'ths 
are within a reasonable distance. 

Plan. — The accompanying Figs. 117 and 118 show the 
ground and chamber plans of a house designed by a Manchester 
architect, and erected at Patricroft in 1896 for £153. In 
this plan the living-room has an area of over 170 sup. ft., 
or if an inner door is provided and the porch deducted, the 
area is over 100 ft. The yard has to be 150 ft. in area, but 
is actually over 190 ft., owing to the provision in the bye- 
laws as to the distance from the back wall of the house being 
regulated by the height of the building. By a compact 
arrangement of Stairs no space is lost, and three bedrooms 
are easily secured. The area occupied (including half width 
of street and passage) is 105 sup. yd. 

The plans of another cottage designed by the same architect 
are illustrated in Figs. 1 19 and 120. The ground plan (Fig. 119) 
is much the same as that of the previous cottage (Fig. 117), 
but is 2 ft. 4 J in. wider. This makes the living-room and kitchen 
more spacious, but the chief advantage is perceived on the 
upper storey, where (see Fig. 120) a bathroom has been 
arranged, in addition to three bedrooms. The area occupied 
(including the half width. of a 12-yd. street, and a 9-ft. back 
passage) is 123 sup. yd., and the cost (in 1898) was £168 
per house. 

Area of Site. — This should be as large as possible, and is 
entirely governed by the cost of the land. It may be taken 
as a standard basis that a working man should not pay more 
than Is. per week for ground rent (unless he makes gardening 
a hobby, in which case a larger sum is allowable). This equals 
52s. per annum. Thus if land can be obtained at Id. per 
yd. per annum, he may acquire a site of 624 sup. yd., whilst 
if the ground rent is 8d. per yd. per annum, the site must not 
be larger than 78 sup. yd., including the land thrown into 
front street and back passage. In districts where ground 
rents are not customary, and where land is purchased out- 
and-out, it means that, reckoned at 3 per cent., the site must 
not cost more than £86 13s. 4d. ; at 4 per cent., not more 



A TYPICAL DWELLING. 



143 



than £65 ; and at 5 per cent., not more than £52. These 
and the intermediate areas are shown in the accompanying 
tabular form. 



Area in 
sq. yards. 


Ground Rent 
•per Yard. 


At 3 PER Cent. 

Total Cost, 
£86 ISs. 4d. 


At 4 PER Cent. 
TctaZ Cost. £65. 


'At 5 PER Cent 

Total Cost, 
£62. 


Cost per 


Yard. 


Cost per Yard. 


Cost per Yard. 






8. 


d. 


s. d. 


s. 


d. 


78 


8d. 


22 


2 


16 8 


Ie3 


4 


89 


7d. 


' 19 


5 


14 7 


11 


8 


104 


6d. 


16 


8 


12 6 


10 


0- 


125 


6d. 


13 


10 


10 5 


8 


4 


156 


4d. 


11 


1 


8 4 


6 


8 


208 


3d. 


8 


4 


6 3 


5 





312 


2d. 


5 


6 


4 2 




4 


624 


Id. 


2 


9 


2 1 


1 


8 


_ 















These areas include the half width of street and passage, 
and it will consequently be seen how small the actual area 
covered bv the house will be in those districts where land 

if 

is dear, and where the Model Bye-laws of the Local Govern- 
ment Board as to areas of space behind houses are in force. 

Competitive designs of houses costing about £150 to build 
have appeared in " Building World." Several of these plans 
were excellent for the purpose, but now that the cost of 
material and labour have increased they could not be erected 
for anything near the sums named ; among them, however, 
may be selected four which are on the lines here laid down, 
and which could probably be erected for something near 
£150. That shown by Figs. 121 to 123 is very good in plan 
and economical in arrangement ; the scullery should be 
omitted, and would result in the saving not only of its cost 
and the land it stands upon, but also of the land alongside. 
Omitting the scullery, the house might be erected for £150. 
The area occupied (including half width of street and passage) 
is 142 sup. yd., or omitting the scullery, 125 yd. 

Size and Height of Booms. — In an earlier paragraph of 
this chapter (see p. 140), it has been urged that the living-room 



144 SANITARY CONSTEUGTION IN BUILDING. 

should be large enough to contain with comfort the whole 
of the family when assembled in the evening. For comfort 
and for facility of ventilation there should not be less than 
300 cub. ft. per head. According to a Memorandum published 
by the Local Government Board, the height recommended 
is 9 ft. A room, therefore, of 144 sup. ft. area by 9 ft. high 





Fig. 121.— Ground Plan of House 
costing £150. 



Fig. 122.— First Floor Plan 
of Fig. 121. 



= 1,296 cub. ft., which, divided by 300 cub. ft., implies that 
four adults and a baby, or two adults and four or five children, 
would not be overcrowded. (See Chapter VII.) 

Bedrooms should be not less than 9 ft. in height, and 

attics, or rooms partly in the roof, should be 9 ft. in height 

for two-thirds of their area, not less than 5 ft. at the lowest, 

and average not less than 8 ft. 

. Ventilation of Rocms. — Where a room has a fire-place 



A TYPICAL DWELLING. 145 

there ie no need to fit up an elaborate and costly ventilating 
apparatus. All that ie necessary is not to stufi up the chimney, 
and to open the window judiciously. The whole subject ol 
ventilation is dealt with in Chapter VIII. The theory of 
ventilation is a continuous inflow of fresh air, so arranged 
as not to produce a perceptible draught, and a constant 
outflow of foul and exhausted air. The inflow may be man- 



Fig. 123.— Section of Fig. 121. 



aged by constructing a Htnckes-Bird bar for the window as 
described and illustrated in Fig. 105, on p. 130 ; a bar of 
timber about 3 in. by 1 in., and in length equal to the width 
of the window opening. The bar may be either fixed or 
loose. When loose, the lower sash of the window is opened, 
the bar laid on edge under the sash, and the sash shut down 
upon it : there is then an opening between the meeting bars, 
about J in, in width, by the length of the window, or say 
3 ft. =27 sup. in. of fresh air inlet. When fixed, the lower 



146 SANITARY CONSTRUCTION IN BUILDING. 



fcead ig taken off, the bar fixed where the bead originally 
was, and the bead re-fixed on the top of the bar. 

The design shown by Figs. 124 to 126 is not so compact 




Fig. 121.— Ground Plan of 
14-ft. 6-in. House. 




Fig. 125.— First Floor Plan 
of Fig. 124. 



in plan, but has a much narrower frontage. The cost is 
given at £162 10s. The area of land occupied is about 
129 yd. 



A TYPICAL DWELLING. 



147 



Space at Rear of Houses. — The majority of local authorities 
insist upon at least 150 ft. of yard space, though in some 
districts the requirement is 200 or even 250 sup. ft. The 
foregoing calculations are based upon an area of 150 sup. ft. 



3 




^ai 




I— t 

bb 

«M 
O 

o 

•l-l 



CO 



bo 



This has to extend the whole width of the building, and is 
to be covered with flags, asphalt, concrete, or other impervious 
paving. The Model Bye-law, however, allows the water- 
(iloset and ashpit to be erected on the 150 ft. The distance 
across the open space varies with the height of the house, 



148 SANITARY G0N8TRUGTI0N IN BLILDING, 

but in no case has it to be less than 10 ft. It will there- 
fore be seen that to obtain this minimum, and the 150 ft. 
area, the width of the house must be 15 ft. Where the house 
is less than 15 ft. wide, the distance across must be greater 
than 10 ft. This, however, is no hardship, as the 10 ft. 
distance only applies to houses under 15 ft. in height. Where 
the house is over 15 ft. in height (but under 25 ft.), the dis- 




Fip:. 127.— Plan of Ground and First Floor of 12-ft. 9-in. House. 



tance across the space has to be 15 ft. ; the width of the 
house may therefore be narrowed to 10 ft. without infringe- 
ment of the regulations. (See p. 108.) 

In the design shown by Figs. 127 and 128, in which there 
is space sufficient for only two bedrooms, the cost is given 
as less than £100. If the area of the house were slightly 
increased so as to allow of three bedrooms being arranged 



A TYPICAL DWELLING, 



li9 



the plan could be carried out for less than £150. The total 
area occupied (including half street and passage) is 95 yd., 
but enlarged as suggested would probably reach 110 
sup. yd. 

Roof Covering, — The roofs will have to be covered with 
incombustible materials, and for a working man's house the 
choice is practically limited to slates or tiles, except in those 
districts where very thin flags are used for the purpose. 




II ilBlJI HIIIIU...UII II.IB 




Fig. 128.— Section of Fig. 127. 



Thatch, of course, is prohibited. Tiles will be the cheaper 
in a district where they are made and univrersally used, and 
always look better than slates ; but generally slates will be 
found the cheaper and to require less repair in the course 
of years. As regards roof timbers, though the Local Govern- 
ment Board have not issued a code of sizes, one has been 
drawn up which has received its sanction. (See p. 84.) 

Floors. — The floors of the living-rooms and bedrooms 
fiihould be of timber ; of sculleries, yards, cellars, etc., of 



150 SANITARY UONSTBUGTION IN BUILDING. 

flags or concrete. Heie, as foi roofs, the Local Government 
Board approve of the code drawn up and sbown on 

p. 97. 

Stair* are also referred to in Chapter VII. The whole 
suhject of staircase construction ia dealt with very fully in a 
companion volume in the series entitled " Practical Staircase 
Joinery," price 2s., puhliahed hy Cassell and Co., Ltd. 




. Hoose. 



The design shown hy Figs. 129 to 131 is very much on the 
lines of Fig. 121 above mentioned. The coat was £150 ; 
the area occupied, including the scullery, and the half street 
and passage, is 134 yd., but if the scullery be omitted it would 
only be 119J sup. yd. 

ConstTuctum ol WcUls. — These will have to be of good 



A TYPICAL DWELLING. 



151 



bricks, stone, or other hard and incombustible materials, 
properly bonded and solidly put together with lime mortar, 
cement, or cement mortar. Half -timber work and cavjty 
walls may be used in certain positions and under certain 
circumstances, in districts where the Model Bye-laws of the 
Local Government Board have been adopted. The founda- 




Fig. 130.— First Floor Plan of Fig. 129. 



tions will have to be good, and if weak must be strengthened 
by a thick layer of concrete or by other means ; the footings 
have a certain projection and depth proportionate to the 
thickness of the wall (see p. 46), and the wall has a certain 
thickness in proportion to its height (see p. 57). A'^ damp- 
proof course must be laid upon the walls a few inches above 
the level of the ground, and if cellars are co^structedthey 



152 SANITARY CONSTRUCTION IN BOILDINQ. 

must be Surrounded with cavity walls, having two damp- 
proof couraee. All theee points are dealt with fully in the 
earlier pages of this manual. 

Frontage. — The frontage or width of a house is a consider- 
able item in reckoning its coat, inasmuch as the cost of paving 
the front street and the back passage is apportioned according 
to the frontage lengths of the properties abutting on the 
streets. Thia charge may be estimated st nearly 20s. per ft., 
so that a house 17 ft. 9 in. wide will have to pay £10 more 



Tig. 131.— Section of Fig. 129. 

than a house of only 12 ft. 9 in. frontage ; and a house at 
the end of a row, with a street alongside the gable wall, may 
have to pay £60 or £70 for paving. 

EsOernal Appearance. — It is not iuteiided to give designs 
for elevations for the dwellings. About 200 designs are 
given in a book entitled " Qieap Dwellings," price Is,, 
pubhshed by Casaell and Co., Ltd. 



A TYPICAL DWELLING. 



153 



Arranging these areas and prices in tabular form, we can 
better compare them : — 



Design, 

Fig. 117 .. 
Fig. 119 .. 


Frontage, 
ft. in. 

14 41 
16 9 


Area, 
sup. yd. 

105i 
123 


Cost, 
£ s. 

153 

168 


d 





Fig. 121 .. 


17 9 


142 


148 





Fig. 124 .. 


14 6 


129 


162 10 





Fig. 127 .. 


12 9 


95 • 


100 





Fig. 127 (enlarged) 
Fig. 129 .. 


15 
17 1 


110 
119J 


150 
150 







Total Cost, — The prospective builder is now in a position 
to estimate what the smallest house that it is desirable to 
erect will cost him, and to ascertain whether it is within his 
means or not. From the table given above it is seen that the 
average area of land required is about 120 yd., and on refer- 
ence to the first table we see that 5Jd. per yd. chief rent, 
or at 4 per cent. lis. 6d. per yd., is the outside price to which 
it is desirable to go. 

The total cost may then be reckoned as follows : — 

£ s. d. 
Land at 4 per cent., not more than . . 65 

House, say 150 

Paving charges, 15-ft. frontage . . 30 

Lawyer, architect, etc. . . . . . . 20 



Total £265 



Where land is cheap, there may be saved from the above 
£30. 



On the house, possibly 

On the paving, possibly 

On the lawyer and architect, possibly 

Total 



so that the cost of the house' complete may be as low as 
£220. If the street is a highway, there will be nothing to 
pay for paving the front, and another £10 will be saved. 



£ 


s. 


d. 


30 








10 








5 








£45 









154 SANITARY CONSTRUCTION IN BUILDING. 

It will be noticed that all the plans selected are arranged 
so as to be built in rows. If the builder of one house can get 
others to join him the cost will be cheaper still. 

Drains. — The drains in connection with a working man's 
house, though not very extensive, should have very close 
attei^tion. They ought to be well arranged, and constructed 
in the best style and of the best materials ; they will thus be 
les3 likely to become defective, and illnesses as well as the cost 
of frequent repairs will be avoided They should be con- 
structed of well-burnt glazed socketed earthenware or stone- 
ware pipes, jointed in Portland cement, laid to even falls 
in straight lines, cut off from the main sewer by an inter- 
cepting trap, and ventilated by means of a shaft from the 
highest point. A 4:-in. diameter pipe is amply large |or the 
amount of liquid sewage that it will have to convey, and in 
no case should it be larger than 6 in. in diameter. The 
whole question of drains is dealt with in a companion manual 
on " Sanitary Conveniences." 

Sanitary Conveniences. — In many districts a wa^er-closet 
is compulsory, whilst in many others privies and waste- 
water closets are allowed. The working man who is building 
himself a house and is well advised will construct an ordinary 
water-closet with flushing cistern supplied from the water 
mains. The whole subject has been dealt with in the manual 
just mentioned. In rural districts, where the working man 
has a hobby for gardening, it may be an advantage for him 
to provide an earth-closet instead of a water-closet ; this, 
however, can only be done with the approval of the local 
authority. Earth-closets are dealt with in Chapter VI. of 
the above-named manual. 

Ashpits should be as small as possible in size in order not 
to encourage the hoarding of ashes and house refuse on the 
premises. Indeed, the hoarding of house refuse should be 
minimised as far as possible by burning all the combustible 
portions either on or under the kitchen fire. A special 
• arrangement for effecting the latter satisfactorily is described 
in " Sanitary Conveniences." The ashes of the burnt refuse 
are then carried out with the other ashes, and there is no 
risk of putrefaction with its accompanying effluvium One 
ashbin in general use is that known as Dr. Quine's Sanitary 
Ashbin, manufactured by Sanitaries Ltd., Statjiam Street, 



A TYPICAL DWELLING. 155 

Pendleton, Manchester. This consists of a pivoted hopper 
suspended in the yard wall ; the refuse is placed in it from 
the yard, and the scavenger empties it from the outside. 
Illustrations and further descriptions of these and other 
ashbins are given in the companion volume on " Sanitary 
Conveniences." 

Conclusion, — The foregoing is a brief attempt to indicate 
the principal points in Sanitary Construction that a working 
man erecting a house for himself should bear in mind. Gener- 
ally this will be the investment of his life's savings and 
economies, and the investment should be characterised by 
the care which the importance of the event demands. On 
the one hand, lavish expenditure is impossible ; on the other, 
undue parsimony is a mistake, the effects of which will be 
apparent as long as the house stands. A careful and honest 
builder should be chosen for the work ; even though his price 
is £10 or £15 higher than the lowest, the extra money will be 
well spent if the work is done well and conscientiously. 
Careful supervision during construction, and close attention 
to the sanitary portions of the work, will result in a minimum 
of repairs, a maximum of comfort, and the absence of death- 
traps. ' 



INDEX. 



Air, Carbonic Acid Gas In, 116 

, Chemistry of, 114, 115 

, Compounds in, 114, 115 

, Dilation of, 127. 128 

, Expansion of, 127 

, Ground, Excluding, 20 

, Nitrogen In, 115 

passing through Outlet Shaft, 

Experiment Determining, 127 

, Pressure of, 128 

, Propeller, Blackman, 131, 132 

Required by Each Person, 117, 

118 

in Rocks, Nature of, 20 

■ in Room, Testing, for Car- 
bonic Acid Gas, 120 

Space and Ventilation, 106 

, Subsoil, Avoiding, 20 

, Testing, 154-136 

Air-grids, Ventilation by, 122 
Air-inlets, Mica Flaps for, 131 

, Sherlngham Valve, 130, 131 

, Tobln Tube, 130 

Air-space at Rear of Buildings, 108 

In Rooms, 101 

Aqueous Rocks, 14, 15 

Arches, Chimneys Supported on, 

76 
Areas, Dry, for Keeping out Damp, 

54 
Artificial Ventilation, 133, 134 
Ashblns, 154, 155 

, Quine's Sanitary, 154, 155 

Asphalt Damp-prof Course, 53, 54 

Basement Floor, Laying, 93 
Beams for Floors, 88-96 

for Public Buildings, 90 

Blackman Air Propeller, 131, 132 
Blue Bricks, Staffordshire, 53 
Boarded Floor, 94 

Boards, Floor, Filling Crevices be- 
tween, 95 



Boards, Floor, Shrinkage of, 95 
Bonding Brick, Jennings', 42 
, Doulton's, 43 

Ties for Cavity Walls, 42 

Brick Pillars, 48 

. on Cutting Ring, 48 

Bricks, Blue Staffordshire, 53 

, Doulton's Bonding, 43 

, Essentials of Good, 36 

, Jennings' Bonding, 42 

, Porosity of, 37 

, Sizes of. 36 

Broomhall's Damp-proof Course, 53 
Building Materials, Sanitary, 36-44 

on Medium Ground, Heavy, 50 

• on Soft Ground, 47, 49 

Site, Area of, 142, 143 

, Choice of, 137 

— ■ , Healthiness of, 33 

Buildings, Air-space at Rear of, 108 
, Height of, 110 

on Soft Ground, Light, 49 

, Space in Front of, 104 

, Ventilation of. 113 

Bye-laws, Model, 9 

Carbonic Acid Gas in Air, 116 

, Testing Air for, 120 

Cavity Walls, Bonding Ties for, 42 

, Building, 43 

Cellar Floors, 92, 93 

, Ventilation of, 30-32 

Chaumont's Formula, 117 
Chemistry of Air, 114, 115 

of Coal Gas, 118 

Chimney Flues, Size of, 78 
Chimneys on Arches, 76 

, Construction of, 73-78 

Coal Gas, Chemistry of, 118 
Concrete as Building Material, 38 

for Covering Surface of 

Ground, 20, 22 



INDEX, 



167 



Concrete Pillars, 48 
Copper, for Roof Covering, 83 
Corbetfs Floor, 94 
Corrugated Iron, Roof Covering, 83 
Cost of Building Small House, 153 
Covering for Roof, 149 
Cutting Ring, Brick Pillar Built 
on, 48 

Damp, Dry Areas for Excluding, 54 

, Excluding from External 

Ground, 54 

Houses, Public Health Act on, 

55 

Soil, Living on, 25 

, Test for, 54 

Walls, Remedying, 56 

Damp-proof Course, Asphalt, 53, 54 

, Broomhall's, 53 

, Doul ton's, 53 

, Model Bye-laws on, 51 

, Sheet Lead, 52 

, Slate, 53 

, Staffordshire Blue Brick," 

53 

, Taylor's, 53 

Density of Population, 111 
Dilation of Air, 127, 128 
Doulton's Damp-proof Course, 53 

Bonding Brick, 43 

Drain Pipes, 27 

Draining Subsoil of Buildings, 25, 

26 
Drains, 27 

for Small House, 154 

, Subsoil, 28 

Dry Areas for Excluding Damp, 

54 
Dry-rot, 122 

Caused by Ground Air, 21 

Duroline Roof Covering, 83 

Exhaust Principle of Ventilation, 

132, 133 
Expansion of Air, 127 
External Walls, Height of, 57-78 

, Openings in, 68 

, Recesses in, 78 

Extraction Principle of Ventila- 
tion, 132 

Flagstone Foundation for Wall, 49 
Floorboards, Filling Crevices be- 
tween, 95 



Floors, Area of Rooms, 103 

of Basement, 93 

, Beams for, 88, 89 

, Boarded, 94 

, Bye-laws with Respect to, 97, 

96 

, Cellars, 92, 93 

, Construction of. Bye-laws and, 

87-90 

, Corbett's, 94 

, Joists for, 87-89 

-. Plank, 94, 95 



, Shrinkage of, 95 

for Small House, 149, 150 

, Ventilation below, 121, 122 

Flues, Size of, 78 

, Construction of, 73-78 

Footings, 45, 46 
Forced Ventilation, 131 
Foundations, 47 

on Bed of Rock, 50 

, Flagstone, 49 

Frontage of House, 151, 152 

Galvanised Corrugated Iron for 

Roof Covering, 83 
Gas, Carbonic Acid, in Air, 116 

, , Testing Air for, 120 

, Coal, Chemistry of, 118 

Ground, External, Excluding Damp 

from 54 
, Medium, Heavy Building 'on, 

50 

, Soft, Building on, 47 

, , Light Buildings on, 49 

Ground-air, Dry Rot Caused by, 21 

, , Excluding, 20 

Ground Water, 24 

Hearths, Bye-laws with Respect to, 

96, 97 
Heavy Building on Medium 

Ground, 50 
Height of Rooms, 143, 144 
Hinckes-Bird Air Inlet Bar for 

Window, 145 
House, Aspect of, 137 
, Building Smallest Possible, 

111, 112 

, Cost of Building, 153, 154 

, Drains for Small, 154 

Frontage, 151, 152 

, Sanitary Conveniences for 

Small, 154 



158 SANITARY CONSTRUCTION IN BUILDING, 



House, Smallest Possible. 111. 112 

, Space at Rear of, 147 

, Two-roomed, 111, 112 

, Workman's, Accommodation 

in, 139-155 

Igneous Rocks, U, 15 

Inlets, Air, Mica Flaps for, 131 

, , Sheringham Valve, 130, 

131 

, , Tobin Tube, 130 

, Level for, 129, 130 

, Openings for, 129-131 

Internal Walls, Height of, 57-78 
Italian Tiles, 79 

Jacob's Method of Testing Air, 134 
Jennings' Bonding Brick, 42 
Joists for Floors, 87-89 

, Trimmer and Trimming, 88 

for Warehouses, 88 

Lead for Roof Covering, 81, 82 
, Sheet, for Damp-proof Course, 

52 
Light Buildings on Soft Ground, 

49 

Limes, 39, 40 

Local Government Acts, 10, 11 

Board, 9 

Made Ground, or Tipped Land, 15, 

16 
Materials for Building. 36-44 
Mechanical Ventilation, 131 
Metamorphic Rocks, 14, 15 
Mica Flaps for Air Inlets, 131 
Model Bye-laws. 9 

on Roof Coverings, 82 

Ventilation, 121 

Montgolfier on Ventilation, 127, 128 

Nitrogen in Air, 115 
Nuisance Section of Public Health 
Acts, 55, 56 

Openings in External Walls, 68 

, Inlet, Level for, 129, 130 

, and Outlet, 129 

Ozone, 116 

Pantiles, 79, 80 

Parkes on Ventilation, 132, 133 



Party Walls, Construction of, 60-73 

, Height of. 69-71 

Paving Yards of Houses, 104 
Piles for Building on Soft Ground, 

47, 48 
Pillars, Brick, 48 

, Concrete, 48 

Pipes, Drain, 27 
Plank Floor, 94, 95 
Planning of Streets, 138, 139 
Plenum Ventilation, 131. 132 
Population, Density of, 111 
Portland Cement Skirtings, 96 
Public Buildings. Beams for, 90 

Health Act, 9. 10 

on Damp Houses, 55 

Purlins, Roof, 84, 85 

Quine's Sanitary Ashbin, 154, 155 

Rafters of Roofs, 84 

Rainwater from Roofs, Conveying 

85, 86 
Ream Warter, 24 

Rear of Houses, Space at, 147, 148 
Recesses in External Wall, 72 
Rock, Building Foundations 

Bed of, 50 
Rocks, Air in. Estimating, 19 

, Aqueous, 14, 15 

, Classes of, 14, 15 

, Igneous, 14, 15 

-, Metamorphic, 14, 15 



on 



Roof Construction, 79-86 

, Conveying Rainwater from, 

85, 86 

Covering, Duroline, 83, 84 

; Lead, 81 

Materials, 79-84 



: Slates, 80, 81 

for Small House, 149 

: Tiles, 79. 80 

, Zinc, 81, 82 

Coverings, Model Bye-laws on, 

82 

Purlins, 84, 85 

Rafters, 84 

Rooms, Air Space in, 101 

without Fireplaces, Bye-laws 

on Ventilation of. 123 

, Floor Area of, 103 

, Height of, 143, 144 

, , Bye-laws with Re- 
spect to, 100-103 



INDEX. 



159 



Rooms in Roof, Height of, 102 

, Sizes of, 143, 144 

, Temperature of, 125, 126 

, Ventilation of. 144-146 

, Windows of. 122 

Sand, Testing, 39 

Sanitary Conveniences for Small 

House, 154 
Scurfleld's Ventilation Indicator. 

135, 136 
Sheet Copper as Roof Covering, 83 

Lead Damp-proof Course, 52 

Sheringham Valve Air Inlets, 130, 

131 
Site, Area of Building, 142 

for Building, Choice of, 137. 138 

, Determining Suitahility of. 14 

, Healthy, for Building, 33 

Sizes of Rooms, 143, 144 
Skirtings, 95, 96 

, Portland Cement. 96 

Slate Damp-proof Course, 53 
Slates, 80. 81 

, Bangor,^ 80 

, Cumberland. 80 

, Laying. 80, 81 

, Welsh, 80 

Soils, Damp, Living on, 25 

, Subsoils and Sites, 14-35 

Stability of Walls, 57-78 
Staflordsl^ire Blue Brick Damp- 

proot Course, 53 
Staircases, Bye-laws with Respect 

to, 97-100. 123 
Stone as Building Material, 37 

Walls, Height of, 68 

Streets, Planning of, 138, 139 
Subsoil, 14-35 

Air, Avoiding, 30 

Draining Beneath Buildings, 

25. 26 

Drains, 28 

Water, 24 

, Raising, 29 

Taylor's Damp-prof Course, 53 

Patent Tiles, 79 

Temperature of Room, 125, 126 
Terra-cotta, 37 

Testing Air, 134-136 

Thatch Roof Covering, 82, 83 

Thickness of Walls, 59-78 

Ties, Bonding, for Cavity Walls, 42 



Tiles, 79. 80 

, Italian. 79 

. Pantiles, 79, 80 

, Taylor's Patent, 79 

, Venetian, 79 

Tipped Land, or Made Ground, 15, 

16 
Tobin Tube Air Inlets, 130 
Trimmer and Trimming Joists, 88, 

89 



Vacuum Principle of Ventilation, 

132, 133 
Venetian Tiles, 79 
Ventilation, 106 

■ by Air-grids, 122 

, Artificial, 126. 133, 134 

of Buildings, 113 

■ Cellars, 30-32 

, Exhaust Principle of, 132, 133 

, Extraction Principle of, 132 

without Fireplaces, 123 

below Floor, 121, 122 

, Forced, 131 

, Mechanical. or Forced, 126, 131 

, Model Bye-laws on, 121 

, Montgolfler's Rule, 127, 128 

, Natural System of, 126, 127 

, Parkes on, 132. 133 

. Plenum, 131. 132 

of Rooms. 144-146 

• without Fireplaces, 

Bye-laws on, 123 

Staircases, Bye-laws on, 

123 
, Vacuum Principle of, 132 



Walls, Cavity, Bonding Ties for, 
42 

, Building, 43 

Damp. Remedying, 56" 
Determining Height of; 57, 58 
Length of, 57, 58 



External, Height of, 57-78 

, Openings in, 68 

Flagstone Foundation for, 49 
Internal, Height of, 57-78 
Materials for Building, 36 
Party, Construction of, 69-73 

, Height of, 69-71 

Recesses in External, 72 
of Small House, Construction 
of, 150, 151 



160 SANITARY OONSTRUGTION IN BUILDING. 



Walls, Stability of, 57-78 
-r — , Stone, Height of, 68 

, Thickness of, 59-78 

Warchouser Joists for, 88 
Water, Ground, 24 

, Raising Subsoil, 29 

, Ream, 24 

, Subsoil, 24 

Williams-Freeman on 
Health, IH 



General 



I Windows, Hinckes-Bird Air Inlet 

Bar for, 145 

of Rooms, Bye-laws on, 122 

, Size of, 122 

Workman's House, Accommodation 

in, 139-155 

Yards, Paving, 104 
Zinc. 81, 82 



Printed by Cassell and Company, Limited, La Belle Sauvaoe, London, E.G. 



"WORK HANDBOOKS." 

A Series of Practical Manuals. 
Edited by PAUL N. HASLUCK, Editor of "WORK." 

Illustrated. Cloth, is. net ; or Post Free, is. 2d. each. 

PhotO^apbiC Chemistry. Co»/«n^s.— introductory ; Relation of 
Chemistry to Photography. Some Fundamental Chemical Laws. Meaning of Symbols 
and Equations. Water, its Properties and Impurities. Oxygen and Hydrogen Photo- 
graphically Considered. Theories Concerning the Latent Image. Chemistry of 
Development, Toning, Intensification, etc. - Nitrogen Compounds Employed in 
Photography. The Halogens and Haloid Salts. Sulphur and its Compounds. 
Metals, Alkali Metals, etc. Organic or Carbon Compounds used in Photography. 
Pyroxyline, Albumen, (^latine, etc. Benzene and the Organic Developers. Index. 

Glass Writing, lUnbossing, and. Fascia Worlc Contents.— 

Plain Lettering and Simple Tablets, Gold Lettering, Blocked Letters, Stencil Cutting, 
Gold Etching Embossing, French or Treble Embossing, Incised Fascias, Stallplates, and 
Grained Background ; Letters in Perspective and Spacing Letters ; Arrangement of 
Word» and Colours, Wood Letters, Illuminated Signs, Temporary Signs for Shop 
Windows, etc. 129 Illustrations. 

VloUns and Other Stringed Instruments. Con^m^s.— Materials 

and Tools for Violin Making. Violin Moulds. Violin Making. Varnishing and Finishing 
Violins. Double Bass and a Violoncello. Japanese One-string Violin. Mandoline 
Making. Guitar Making. Banjo Making, etc etc. 177 Illustrations. 

Pianos : Their Construction, Tuning, and Repair. Contents.^ 

Piano Construction. The Action : Completion of Piano. The Purchase and Choice of a 
Piano. Care, Maintenance, and Cleaning. Tuning Pianos. Piano-repairers' Tools. 
Repairing Piano Actions. Restringing and other Repairs. Polishing and Renovating 
Piano Cases, etc etc 74 Illustrations. 

Terra-cotta Work : Modelling, Moulding, and Firing. Contents, 

—History and Manufacture of Terra-cotta. Models and Moulds for Terra-cotta Work. 
Kiln for Firing Terra-cotta. Modelling and Moulding Finials and Chimney Pots. Panels, 
Medidlions and Friezes. Garden Vsise and a Flower-pot Stand. Keystones. Measuring 
and Pricing Terra-cotta Work. Memorial Monument. Ornamental mountains. Umbrella 
Stand, etc. 345 Illustrations. 

Sewing Machines : Their Construction, Adjustment, and 

Repair. Contents.— The Development of the Sewing Machine. Types of Sewing 
Machines. Workine and Adjusting Machines. Adjustments for Broken Needles, 
Broken Thread, andMissed Stitches. Repairing Sewing Machines. Useful Attachments, 
and Auxiliary Devices, etc. 99 Illustrations 

Clay Modelling and Plaster Casting. C^w/^m/x.— Introduction ; 

Drawing for ModeUers. Tools and Materials for Clay Modelling. Clay Modelling. 
Modelling Ornament. ModeUing the Human Figure. Waste-moulding Process of Plaster 
Casting. Piece-moulding and Gelatine-moulding. Taking Plaster Casts from Nature 
Clay Squeezing or Clay Moulding, etc. etc. 153 Illustrations. 
TelescopO Making. C(?/f/^M/x.— Introduction : Materials for Telescope 
Making ; Making the Mounting ; Making the Clasp and Clamp ; Vertical and Horizontal 
Slow Motions : Completing the Mounting : Telescope Body ; Lenses for the Telescope ; 
Object End ot Telescope ; Eyepieces, etc. etc 318 Illustrations. 

Bllcroscopes and Accessories. C^^n/^/f^x.— Construction of a Stand 

Microscope ; Making and Fixing Mechanical Sta^s ; Finishing and Lacquering 
Microscope Brasswork; Improved Mounts for Small Microscopes : Microscopists' Lamps 
and BullVeye Condensers \ Micrometers and the Measurement of Microscopic Objects ; 
Turntables tor Ringmg Slides, etc. 140 Illustrations. 

BLnottlng and Splicing Ropes and Cordage. Cm/««/j.— Introduc- 
tion: Rope Formation. Simple and Useful Knots. Eye Knots, Hitches, and Bends. 
Ring Knots and Rope Shortenings. Ties and Lashings. Fancy Knots, etc. etc. 208 
Illustrations. 

Beehives and Bee Keepers' Appliances. Contents,— lnxxo6xict\on : 

Bar-firame Beehive. Beehive Tor Temporary Use. Tiering Bar-firame Beehive. The 
" W.B.C." Beehive. Furnishing and Stocking Beehives. Observatory Beehive for Per* 
manent Use. Observatory Beehive for Temporary Use, etc. etc 155 Illustrations. 

Electro-plating. C^w^m/J.— Introduction : Tanks, Vats, and other Ap- 
paratus ; Batteries, Dynamos, and Electrical Accessories ; Appliances for Preparing, and 
Finbhing Work; Silver-plating; Copper-plating; Gold-plating; Nickel-plating and 
Cycle-plating; Finishing Electro-plated Goods, etc etc. 77 Illustrations. 

Cycle Building and Repairing. Contents.— The Components of a 
Cycle. Building the Wheels. Building the Cycle Frame. Finishmg the Cycle. Building 
a Tandem Cycle. Building a Carrier Tricycle, etc. etc. 190 Illustrations. 

Saddlery. C^f/m/x.— Gentleman's Riding Saddle. Panel for Gentleman's 
Saddle. Ladies' Side Saddles. Children's Saddles or IMlches. Saddle Cruppers. 
Breast Plates and Other Accessories. Riding Bridles. Breaking-down Tackle. Head 
Collars. Horse Pothing. Knee-caps and Miscellaneous Articles, etc etc 177 lUus. 

Upholstery. Contents.— IJ-phol&ttxecs* Materials. Upnolsterers Tools. 
Webbing, Springing, Stuffing, and Tufting. Making Seat Cushions and Squabs. 
Upholstering an Easy Chair. Upholstering Couches and Sofas Upholstering Foot- 
stools, Fenoerettes, etc Miscellaneous Upholstery, etc. etc. 162 Illustrations. 

Leather Working. Contents. — Qualities and Varieties of Leather. Strap 
Cutting and Making Letter Cases and Writing Pads. Hair Brush and Collar Cases. 
Hat C^es. Banjo and Mandoline Cases. Bags, Portmanteaux, etc. etc. 15a Illustrations. 

Harness Making. Contents.— 1^9xnts& Makers' Tools. Harness Makers' 
Materials. Simple Exercises in Stitching. Looping. Cart Harness. Cart Saddles. Fore 
Gear and Leader Harness. Plough Harness, Bits, Spurs. Stirrups, etc. etc 197 lUus. 

House Decoration. Contents.— Co\ova and Paints. Pigments, Oils, 
Driers, Varnishes, etc Tools used by Painters. How to Mix Oil Paints. Distemper of 
Tempera Painting. WhItewMhIng and Decorating a Ceiling, Painting a Room, etc. etc. 
79 Illustrations. 

[Continued on next page. 
CASSELL & COMPANY, Limited, La Belie Sauvage, London^ E.C 

I 



" WOttK " HANDBOOKS (continued). 




-Single Luitcms. 

T OpttLAl LanlFrrdL Opdul LafttBfn 

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FbOtOKimpiiy. Ciwftwtr.— The Camera and iu Accusoriti. The SCndio 



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