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Course on Better Building: Proceedings of Meeting, April 26 and 27,
1955
Ser TH]. N21t2 no' 3L e . 2 BI,DG
NATIONAL NESEARCH
COINCIL
CANADA
DTVTSIOIil OF BUII,,DING RESEARCE
gOl'RSE ON BETTER BUII,DII{G
Pnoceed.Lngs of Meet5.ng, Aprll
25 and 2f , L955
f;rirht*Xann
Technlcal Faper I{o, 3I"
,
of thE
Dl.vLeLon of Bulldtng Eeeea.noh
Ottaw*
oetober L955
( 1 )
PREFACE O n e o f t h e g r e a t p r o b l e m s c o n f r a n t l n g a n y r e s e a r c h o r g a n i z a t l o n 1 s t h e d l s s e m l n a t l o n o f l n f o r m a t l o n t o t h o s e w h o c a n m a k e u s e o f t h e r e s u l - t s o f w o r k d o n e i n t h e l a b o r a t o r y a n d i n t h e f i e l d . T h i s i s p a r t i c u l a r l y t r u e l n t h e c o n -s t r u c t i o n f i e l d s i n c e t h e r e l s a t r e m e n d o u s a m o u n t o f i n f o r -m a t l o n a v a l l a b l e f r o m w o r k d o n e a t r e s e a r c h e s t a b l l s h m e n t s t h r o u g h o u t t h e w o r l d . f n a n a t t e m p t t o p a s s a l o n g s o m e o f t h e i n f o r m a t l o n a v a i l a b l e a t t h e D l v l s l o n o f B u l l d i n g R e s e a r c h , a B e t t e r B u i l d i n g C o u r s e w a s h e l d o n A p r i l 2 6 a n d 2 7 t n t h e B u l l d l n g R e s e a r c h C e n t r e o n t h e i t { o n t r e a l R o a d l n O t t a w a . A t t h l s C c u r s e , s e v e n p a p e r s w e r e p r e s e n t e d " b y m e m b e r s o f t h e s t a f f o f t h e D i v l s i o n o n t h e v a r " i o u s a s p e c t s o f h o u s e c c n s t r u e t l o n r a n g t n g f r o m s o l l s a n c l h o u s e f o u n d a t i o n s , t h r o u g h m a s o n r y a n d . w o o d . - f r a m e c o n s t r : u c t i o n n e o n c r e t e , l n s u l -a t l o n -a n d h o u s e h e -a t i n g e q u i p m e n t . A t i h e e n d c f e a c h o f t h e p a p e r s , a d l s e u s s i o n p e r i o d w a s h e l d , T h e f i n a l s e s s i o n o f t h e C o u r s e w a s a g e n e r a l d i s c u s s i o n o f a 1 l - o f t h e p a p e r s a n d a n o p p o r t u n i t y w a s g l v e n t o c o n r m e n t c n t h e f o r m o f t h e p r e s e n t a t i - o n s a n d t h e n c e d f o r t h l s t y p e o f e o u r s e . T h e f o l L o w i n g 1 s a r e c o r d o f t h e p a p e n s w h i c h l n c o r p o r a t e s t h e q u e s t i o n s w h l c h w e r o r a l s e d i n t h e e i i s e u s s l o n p e r l o d f o l l o w i n g t h e p r e s e n t a t i o n o f e a c h n a n e r . T n t h e f l n a l s e s s i o n s , t h e g e n e r a l e o n s e n s u s w a s t h a t s u c h c o u r s e s a r e v a l u a b l e t o t h e e o n s t r u c t l o n i n d u s t r y e n d . s h o u l d b e c o n t l n u e d . f t w a s s u g € : e s t e d t h a t i - n f u t u r e t c o u r s e s b e h e l d d u r i - n g t h e i q l n t e r m o n t h s a s t h i s w o u l d p e r r n i t a g r e a t e r a t t e n d a n c e a m o n g c o n s t r u e t l o n s u p e r -l n t e n d e n t s a n d c o n t : : a c t o r s " T ' h i s f i r s t B e t t e r B u l l d i n g C o u r s e w a s l n t h p f o r r n o f a n e x p e r i m e n t s i n c e n o t h i n g l l k e t h i s h a d c r e v i o u s l y b e e n a t t e m p t e d b y t l i e D i v l s l o n o f B u l l d t n g R e s e a r e h a n d t h e n u m b e r o f p e o p l e a t t e n d l t r g t h e C o u r s e w a s r e s t r i c t e d . I n v i t a t l o n s t " l e r e s e n t t o t h e h o u s e b u l l d e r s i n t h e O t t a w a a r e a , b u i l d i n g i n s p e e t o r s o f C e n t r a l M o n t g a g e a n d H o u s i n g C o r p o r a t l o n a n d o f f i c l a l s f r o m t h e D e p a r t m e n t o f V e t e r a n s A f f a l r s . f n a l l , 4 7 a t t e n d e d t h i s C o u r s e . A l i s t o f i h o s e w h o a t t e n d o d t h e O o u r s e i s i n c l u d e d a s A p p e n d l x A o f t h i s R e p o r t . R . F . L e g g e t , D l r e e t o r( 1 r )
TABLE OF CONTENTS i'age P r o g r a n o f ] 3 e t t e r B r r l l d i n g C o u r s e . . . o o . c . . . . 1 I n t r o d u c t l o n t o C o u r s e b y R . F , L e g g e t . . e . . . ! r . . . . , 2 S o 1 l s l - n l { o u s e C o n s t r u c t i o n b y C t B . C r a w f o r d . e . . . , . . . . . . . . r . . . . . o o , . . e . . . . , o c 4 F o u n c i a t l o n s f o r H o u s e s b y D . C . T l b b e t t S r . . . o o . . . . o ' . . . . . ' . . . . o . . 1 0 G o o d P r a c t i c e l n M a s o n r y W a I I C o n s t r u e t l - o n b y H . B . D i c k g n s . . . . ' . . . r o o . . . o . . . o . . o o o . . c o o o 1 9 D e v e l o p m e n t o f l , u J o o d - f r a m e C o n s t r u c t i o n b y D t B . D o r e y . . . o o a . . o . . o c . o . . . , . . . o o . . . o , 2 7 G o o d " C o n c r e t l n g P r a c t i c e b y E . G . S w e n s o n . . o . ' . o . . ' . . . . ' . . . 6 . o c . o . . i . o o 3 7 A p p l i c a t i o n o f f n s u l a t i o n a n d V a p o u r B a r u i e r s b y t J " I { . 8 a 1 1 . . o . o o c . . o o . . c . . . . o . . . o c o o . . . r o 3 9 I { o u s o H e a t l n g E q u l p m e n t b y A . G . h J i 1 s o n . . . r o . . . o o . . o . o o . . . o . . . o . l + 6 , A . p p e n d i x A : L l s t o f t h o s e p r e s e n t e t t h e B e t t e r B u i l d l n e C o u r s e}IATIONAL NESEARCH
COUNCTL
CANADA
DTVTSIO$ OF BUILDING NESEARCH
BETTER BUILDII{G COUNSE
Aprll
26 and. 2J, 1955
PNOGNAM
Cou^nso
Chalrman - C,B. Cnocken, Bulldtng Practlee Construetlon
$ e e t L o n
Tuesday. Aprll 26
F l o r n l n g :
9 : 0 0 - 1 0 : 0 0 - R e g l s t r a t l o n "
1 0 : 0 0 - ]'OtL$ - fntroduotlon to Courso by R.F. Legget,
Dlrector,
Dtvlston of Bulldlng Beseaneh.
1 0 1 1 5 - l L : 1 5 - S o l l s ln Houge Constructlon,
C , B n C n a w f o r d , S o 1 l Mechanlcs Seetlon.
( l 5 - m l n u t e recese)
l L 1 3 0 - tZ:45 - FoundatLons for Eouses, D.C. Tlbbette,
Bulldlng Praetlao Gonstruetlon Sectlon.
( Luncheon )
Afternoon:
2:00
3:15
Good Praetlee ln l,tasonny WaIl
-
Construcf;ton, E.-8. DtckLns, BulJ-dlng
P r a c t l e o Eouslng $ectlon.
( l 5 - m i n u t e reeess)
3z3O - l+;30 - Development of Wood-frame Constrtletlon,
D . B . D o r e y , B u l l d l n g Deslgn $eetlon.
Wednesday. Aprll 27
M o r n l n g t
9 : 3 O - 1 0 : h 5 - G o o d C o n e r e t l n g P r a c t L e e , E . G . S w 6 n s o n ,
Bullding Matenlals Section.
( L 5 - m l n u t e necess)
L1:00 - L2:l+9 - Appllcatlon
of fnsulatlon
and Vapour
B a r r l . e r s , W . H o 8a11, Bulldtng Praetlee
Ilouslng Sectlon.
(Luncheon)
A f t e n n o o n t
2 l 0 O - 3tLt - Ilouse Heatlng Equlpment, A.G. Wllson,
B u i l d l n g Senvlces $ectlon.
( l 5 - m l n u t e reeess)
3 : 3 0 - [:30
- Genenal $ession - this perlod open fon
q u e s t l o n e and dleeuselon of butldlng
p r o b l e m a .
2
-I$TNODUGTTON
TO BUTIDING COURSE
by
R . F o Legget
D l r e e t o r , Dlvlslon of Bulldtng Researeh,
S a t l o n e l Research Councll
0n behaLf of my col leagues and myeelf r extend. ts arL attendlng thts coaference a Hamr welcome dld to alr r wlsh to e x p r e s s t h e hope that the eonference wlll p r o v e useful and l n e t r u c t L v € . T h " b u l l d l n g l n w h l e h w e a r e m e e t l n g w l l l b o new_to Seny and tho l{atlona1 Reseaneh CouncLl ftself nray not b e f e m L L l a n t o sorne of those attendlng. A c c o r d l n g l y l t - s e e n s approprlate to cay a few words by way-of introdr,lc[r6n ebout tlrg Counel-1, the trlvLsLon, and t[rts butldlng ln ord.er that a ' 1 1 p r e s e n t may know the setttng ln whleb ttrts conferenea is b e l n g h e l d .
T h e } i l a t l o n a l Eesearch couneil ls a epeelal publlc e g e n e y , t h e Pr.esldent of whleh reports to the pnlvy council c o r u n l t t e e o f s c i e n t l f l e a n d r n d u s t r l a l R o s e a r c h " f h e n a m e o f t h e c o u n e l l l e u s e d t o d e s e r l b e s n a c t u a l c o u n c i l _ o f z 0 d l s t l n g u l s h e d c a n a d l a n s w h o r n e e t four times a year and act e s e n a d v l s o t r y body on many matters of natlonai nesearch l n t e r e s t . T h e y a l s o m a k e g r a n t s fon research work to
unl-versltles and award many scholarshtps for the encouregement
o f y o u n g r e s e a n c h workers.
r h a n a m G l e u s e d . a l s o to deseribe a large operatlng r e s e a r e h o r g a n i z a t t o n w h l c h n o w has a staff o f a b d u t 3rooo a n d l e b o n a t o r t e s 1 n O t t a w a , H a l l f a x , a n d s a s k a t o o n . r r r t s r e s e a r e h w o r k of the Couneil 1s carrled out ttrrough Dlvlslons
, P h y s l c s ( P r " l n e a n d A p p l t e d ) , i - n e e r t n g , R a d l o a n d E l e e t r l c a l )ho Phls Dlvl,slon of Bul1d-L I t h e D l v l s t o n s , h a v L n g b e e n staff of about 150 and is
p n l v l l e g e d t o o e e u p y t h i s Bullding R e s e a r e h 0 e n l r e w h l e h w a e d e s l g n e d a n d eonstrueted for lte Ipecial usc.
T h e t a s k o f t h e D l v l s l o n l s t o p r o v l d e a r " e s e a r c h service to the buildlng lndustr'Jr of canadl. Tho Dlvtslon ls c o n s c L o u g o f lts prlvllege l n b - e l n g a Junlor member of, thle l a t e s t o f c a n a d l a n l n d u s { r l e s . r n i t s w o r k i t h a s b e e n f a v o u r e d u r l t h the most remarkable eo-operatlon from aLl
b r ^ a n e h e s o f thc industry, T h e D i v l s l o i r a p p r e c l a t e s t h a t n o t g n r y m u s t l t c a r r y out research wonk ror the beneflt of thc l n d u s t r y b u t t h a t lt must see to it that results of lbs own regearch work and of other butldlng research raork are mad.e known to the l-ndustry throughout cdnada. rn so&s ways thls
3
-b u s l n e s s o f t r g e t t i n g t h e r e s u l t s o f r e s e a r c h a c r o s s s l s t h e n o s t d i f f l c u l t a n d a t t h e s a n e t t m e t h e m o s t l m F o r t a n t o f t h e t a s k s w h l e h t h e D l v l s i o n f a c e s , I t h a s b e e n s a l d , a n d w l t h s o m e d a g r e e o f t r u t h , t h a t l f o n l y w e c o u l d p u t t o u s e t h e i n f o r m a $ i o n r e g a r d i n g L m p r o v e d b u l l d l n g p r a c t i c e s w h l c h l s a t p r e s e n t t o b e f o u n d . l n p u b l l c a t l o n s i n t h e I ) . B . R . L i b n a n y r a n l m m e d X a t e l m p r o v e m e n t l n t h o s t a n d a n d o f Canadlan b u l l d l n g w o u l d r e s u l t , T h e r e l s o n e b u i l d l n g r e s e a r c h o r g a n l z a t l o n k n o w n t o t h e D l v i s l o n w h l c h c a r r l e s o u t a l l l t s n e s e a r c h w o r k w i t h o u t l a b o r a t o r i - e s , m e r e l y b y s t u d y l n g c a r e -f u I I y a n d a s s e s s l n g f o r l o c a } u s o t h e r e s u l t s o f o t h e r " p e o p l e t s e x p e r l m e n t s t I t s w o r k 1 s s l n g u l _ a r 1 y e f f e c t l v e . T h l s s m a l 1 c o n f e r e n c e l s a n a t t e m p t t o b n l d g e t h e g a p b e t w o e n b u l l d l n g 1 6 s e a n c h a n c l t h e p r a c t l c e o f t h e b u l l d l n g o f h o u s e s . T h e D i v i s l o n h a s h a c i s e v e r a l r e q u e s t s t o a r r a n g e s u c h a c o u r s e a s t h i s . S o m e w h a t n a t u r a l l y t h l s f l r s t e x p e r -l m e n t a -l e o n f e r e n c e -l s b e -l n g h e -l d i n O t t a w a w h e r e w e h a v e a -l -l t h e f a c l L i t l e s o f t h e B u l l d i n g R e s o a r c h C e n t n e a v a l - I a b l e t o u s a n d o p e n f o r y o u r i n s p e c t l o n . A t e a m o f s p e a k e r s h a s b e e n s e l e c t e d f r o m t h e s t a f f o f t h e D i v l s l o n . A l l a r e y o u n g m e n a n d s o t h e y d o n o t h a v e the accumulated experience ln actual b u i l e ] . l n g t h a t 1 s t j " r e p o s i t l o n o f s o m a n y a t t e n d t n g t h . e m e e t l n g . A t t h e s a m e t l m e t h e y m a k e u p f o r thelr l a c k o f b u i l d l n ge x p e r l e n c e w i t h t h e l r e n t h u s l a s m f o n b u l l d i n g r e s e a r c h w o r k . l{e are alr here concerned with finding out .lnlHY certaln thlngs h a p p e n i n b u i l d l n g a n d w h y c e r t a l n p r o b l e m s a r 6 e n e o u n t e r e d . W e a r e g o i n g t o t n y t o s h a r e w i t h y s s some of thls thlnklng l n t h e h o p e t h a t w e m a y b e a b I e , b y m u t u a l r l l s c u s s l o n , t o h e l p o n e a n o t h e r a n d s o t o m a k e a v a i l a b l e t o y o u s o m e o f t h e l n f o r r a a t l o n w h i c h w e h a v e . N o c o n f e r e n c e o f t h i s c h a r a c t e r c a n b e a s u c c e s g w i t h o u t t h e p a r t i c l p a t i o n o f t h e a u c l e n c e . ' r J e thorefore hope t h a t y o u w 1 1 1 n o t h e s l t a t e t o v o l c e a n y q u e s t i o n s w h l c h o c c u r t o y o u t o a n y o f t h e s p e a k e r s . T h e y w 1 1 1 w e l e o m e y o u r eues-t l o n s a n d eues-t h e m c r e eues-t h e y h a v e eues-t h e b e eues-t eues-t e r p l e a s e d w l 1 1 eues-t eues-t r e y b e . I f w e f l n d i t a d v i s a b l e w e c a n d e v o t e t i m e d u r i n g o u r s e c o n d a f t e r n o o n t o a q u e s t l o n a n d a n s w e r p e r l o d b u t w e s h a l l l e a v e t h e d e c l s l o n o n t h l s r n a t t e r l n y o u r h a n d s . F l n a l l y w e a r e m o s t a n x i o u s t h a t y o u w 1 1 1 g l v e us the beneflt o f y o u r m o s t f r a n k c r l t l e l - s m o f t h e C o u r s e w h e n l t i s c o m p l e t e d s l n c e w e a r e m o s t a n x l o u s to use the experlence of these turo days ln o r d e r t o 1 a y t h e f o u n d a t l o n s f o r e v e n b e t t e r c o u r s e s l n t h e f u t u r e , h e r e i n O t t a w a a n d a t o t h e r c i t l e s a l l a c r o s s c a n a d a .
O u r e x p e r i . e n c e s u p t o t h i s t l m e i n s h a r i n g p r o b l e m s o f a l l k l n d s w i t h b u l l d e r s a n d b u l l d t n g l n s p e e t o r s I n a l l
p a r t s of Canada encourage us to thlnk that meetlngs such as thls s h o u l d b e a n e s s e n t l a l p a r t o f t h e w o r k o f t h e D l v i s l o n o f
B u l l d l n g R e s e a r c h . w l t h y o u r h e l p w e s h a r l t r y to make these t w o C a y s a s e f f e c t l v e a s p o s s i b l e a n d t h u s , t o g e t h e r , t a k e a n o t h e r s t e p towa::d the development of better buildlng i n C a n a d a .
4-SOTLS IN HOUSE CONSTRUCTION b y G . B . C r a w f o r d
S o 1 1 M e c h a n i e s S e c t l o n
O f t e n s o i l s a l a e n o t eonsldered. serlously 1 n h o u . s e c o n s t r u e t l o n e x c e p t t o n o t e t h a t s o 1 I a t a c o n s t r u c t l o n s l t o means mud wl:en lt ralns, and mud means trouble, Some years B B o r p r a c t l c a l b u l l d e r s , m a l n l y 1 n t h e r o a d b u l 1 d L n g l n d u s t r y t E s s o c l a t e d v a n l o u s p r o b l o m s w i t h c e r t e l n p e c u l l e r l t t e s o f t h e e o l 1 . T h e y d e c l d e d t o t r y t o t d e n t l f y t h e m a t e r l a l , t o s t u d y I t s p r o p e r t l e s , a n d t o r e l a t e t h e s e p r o p e r t l e s t o t h e f l e l d p e r f o r n a a n c c o f t h o s o l 1 . t h l e w a s t h e b e g l n n l n g o f t h e e e i e n e c n o w k n o w n a s s o l 1 m e e h a n l c s . W}IAT IS SOIL?' S o 1 1 l s a m a t e r l a l c o n s L s t i n g o f t h n e o c o m p o n e n t s l m l n e r a l p a r t i c l o s , w a t e r , a n d & . t t : . $ o 1 I s a r e a n b l t r a r l ) - y d l v l d e d l n t o c l a s s e s o n t h e b a s t s o f g r a l n s l z e . f h e s e c l a s s e s a r e g r a v e l , s a n d , s l 1 t , a n d e l a y , f n n a t u r e n s o l - l s e x l s t l n m a n y c o r n b i - n a t l o n s o f t b e s e e l a s s t y p e s . , B e f o r e a t t e m p t l n g t o d e e l w i t h s o l l s w e m u s t b e s u r e o f t h e l n l d e n t l f i c a t l o n . T h e c o & r s s - g r a l n e d s q l l s ( g r a v e l a n d . s a n d ) a r e e a s y t o i d e n t l f y . G r a v e l l s a r n a t e r i a l w i t h _ p a n t -i c l e s l e s s t h a n 3 lnches in diameter and greater than f lneh l n d l a m e t c r . S a n d h a s p a r t l c l e s f n o m $ tnch ln dlameter down t o p a r t l c l c s t h a t a r 6 J u s t v i s l b L e w l t h t h e n a k e d e y 6 . B o t h gravels and sands arc funther subdlvld.od into co&rse, medtum, and flne" T h e l d e n t i f l e a t l o n o f f l n e - g r a i n e d s o i l s ( s l 1 t a n d c l e y ) l - s m u c h m o r e d i f f l e u l t a n d m a n y c o s t l y e r r o r s l n c o & s -t r u c -t l o n w o r k h a v e r e s u l t e d f r o m a n l n c o r r e c t l d e n t i f i c a t i o n . T h e s c s o l l s m a y a l s o b e e l a s s l f t e d a e e o r d l n g t o g r a l n s l z o . f n o r d e r o f d . e c r e a s l n g g r a l n s t z e , s i l - t f o l l o w s f l n e s a n d ; a n d e l a y f o l l o w s s i l t .
There are several slmple we-Jts to flnd out whethcn s l l t o r c l a y f o r m s p a r t o f a s o L l . T a k e a w e t p a t o f s o 1 3 - t m o u l d 1 t l n t o a b a ] l , a n d s h a k e l t v l g o r o u s l y l n t h e c u p p e d h a n d . T h e s r : r f a e e w l l l b e c o m e g l o s s y a n d s h o w f r e e w a t e r . I f t h e s o l I l s a s l l t , t h e f r e e w a t e r w l 1 l - d l s a p p e a r a n d t h s s u r f a c e w 1 1 1 b e c o m e d u 1 l w h e n t h e p a t o f s o l l t s s q u e e z e d b e t w e e n t h e f L n g e r s . T h l s w 1 1 1 n o t h a p p e n w i t h e l a y s o l l s . A n o t h e r m e t h o d l s t o s t r o k e a l u m p o f w e t s o l l w l t h t h e f l a t o f a p e n k n l f c b l a d e o r f l n g e r n a l 1 u s l n g c o n s i d e r a b l - e p r e s s u r o . I f t h i e r e s u l t s l n a s h l n y s u r f a e e r c l a y l s p r e s e n t b u t l f a d u I I s u n f a e e L s p r o d u c e d s l 1 t l s p r e s e n t .
SPECIAL SOIL TYPES 0rgantc So11
Some soils contaln en appreeiable amount of organle m a t t e r . f t l s l r n p o r t a n t t o l d . e n t l f y t h e s e s o l l s b e e a u s e o f
t h e l r c r i t i e a l p r o p e r t t es. T h e y c a n b e l d e n t l f l e d b y a d a r k bror'rn on black eolour and by thelr strong odour, Orgenle
s o l 1 s a r e o f t e n a s s o e l a t e d w l t h p o o r l y d r a l n e d a r e a s , - a n d i h e y a r e u s u a l l y u n d e s l r e b l e & s a f o u n d a t l o n m a t e r l a l b e c a u g q o f t h e l r h t g h e o m p r e s s l b l l l t y "
T o p S o 1 1
Thls ls &. speclel type of organl-c so1l well known f o r l t s p n o p o r t l e s w h l c h s u p p o r t p l a n t g n o w t h " I t t o o l s h l g h l y c o m p r e s s l b l - e . F l 1 1 F l l l L B a m e n - m a d e d e p o s l t o f n a t u r a l s o l l - s o l 3 w a s t c m a t e r l " a l . f t c & n u s u a l l y b e l d e n t l f l e d b y t h e g n a s s , t w l g s , b r i c k s , a n d g l a s s i n t t ; t h e r e . i s u s u a l l y a l a y e r o f t o p s o i l b s n e a t h t h e f i 1 1 . T h i s i s g e n e r e l l y a m a t e r i a l o f q u e s t i o n a b l e p r o p e r t l e s a n d " s h o u l d n o t b e b u l l t u p o n w i t h o u t L n v e s t l g a t l o n . Ttlt_ T l l L 1 s a n u n s t n e , t i f l e d s o I l o f a s s o r t e d g r a i n s i z e s . c o n t a l n a l L r a n g e s o f s o 1 1 g f r o m large boulders down f i n e s t c 1 a y .
I t m a y t o t h e
6
-Eoam
L o e m 1s a term commonly used in agrlculture but not
u s u a l l y used in-englneering.
r h l ) term refeis to-tt e graln
s l z e o f t h e s o i l .
F u r e r o a m c o n s l s t s o f e q u a l p a r t " 5r sand,
s l 1 t and cley.
v a r l a t l o n s
s u c h &s sandy loaro and sllty Loam
r e f e r to a predomlnance of a certaln griln slzeo
WATER IN SOIL
r n e n t t n s o l l w h l c h cs.,uses alL tretlon. The nrtount of waten ra.sonally and thls verlatlon may ; L a s o f t h e soll, f n s o m c h c a v y rhra area, slgnLficant voLumo c h a n g e s oeeun seasonally due to changtng mSisturu eontent, T h t e
9 ? * . g o , i n m o l s t u r e e o n t e n t i s c a u s i d p " " i i y - u t - s e c s o n a l v a r i a t l o n s l n p r e c l p l t e t r . o n . a n d pertly by ine ,ri" 6r solr r n o l s t u r e by treos snd vegetatlon, T h i s r e s u l t s l n l _ o s s o f
s u p p o r t , p a r t l e u l a r l y t o s h a l l o w f o o t l n g s , a n d f l n a l l _ y ceuscs d.amage to the stnucture,
A t s o m s e r e v a t l o n b e r l o w t h e s u r f a c e , f r e e w a t e r l s e n c o u n t e r e d l n t h e s o l l . T h l s e l e v a t l o n r 1 s c a l l e d t h e
g r o u n d w a t e r table. B e l o w t h e g r o u n d w a t e r table all the voLd.s i n t h e s o l 1 & r e flrled w r t h w e E e r . A b o v e t h e g r o u n d w a t e n
t a b L c t h e r e l s u s u a l l y s o m e a l r i n t h e v o i d s oi trre sol1. T h g . g r o u r l d w a t e r t a b l e 1 s t h e e l e v a t l o n a t w h l c h water 1s e n c o u n t e r e d in open wel-rs.. rn coarse-gratned s o i l s a n d s i l t y s o l l s t h e r ^ r a t e n t a b l e can be determlned *asi1y on the Uuffdfirg s l t e _ b y measr:rlng the depth to fnee water ln L bone hole or ! { o u s e n v l n g the occurrehce of fnee water in an excavetlon. s L n e e
" 1 * y s o l r s a r e lmpenrneable, the water leveI must be o b s e r v e d fon a eonsldenabl-e time tn order to accurately deter-m l n e t h e ^ g r o u n d w a t e r level. 0 n m a n y b u i l d i n g s l t e u r t ; ; " ; [ ; ; n w a t e r tabres occur, that ls, bhe waler tablc is at a irrgh e l e v a t t o n 1 o c a l l y , d . u e t o & n t m p e r m e a b l e l_ayer at a relitlvely s h a l l o r s d e p t h .
{.iiAT DOES SoIL D0?
g s t r u c t u r e s . S o m e s o l l s e e n r u t o t h e r s o l l s requlre s p e c l a l r l r e m e n t s p r o p e r l y . S o 1 1 a c t s
p e n e t r a t j _ o n and neduclng heat s u c h a s b a s e m e n t s ,
s o l I 1 s a . p o r o u s materlal w h l c h m o u l d s easily i n t o e n y s h a p e . r t s p p o p e r t l e s a r e m o s t a p p r e e l e t e d w h e n i t i s n o t a v a l l a b l e f o n u s e a n d must be rmportea in order to shape t h e b u l l d i n g l g t 3nd to support g*onth of vegetatlon. r t i s a n e l a t i v e l y s l m p l e m a t t e r t o e x c a v a t e s o i l
7
-o x c a v a t l -o n s w l t h s o l 1 . I t l s a l - e o a s l m p l e m a t t e r t o s h a p e t e r r a c e s , c i i - t c h e s , a n d b a r r i e n s w l t h s o i 1 . S o i l l s a l l v l n g m a t e n l a l . , f t b r e a t h e s d a l 1 y a t s h a l l o w d e p t h s a n d s a a s o n a l l y
at deeper depths due to temperature chenges, This featurc p e r m l t s i t t o s u p p o r t v e g e t a t l o n a n d t o p u r i f y s e w a g e . f t a c t s e s a s t o r a g e r e s e r v o i n f o r p r e e i p l t a t i o n . S o m e t y p e s o f s o i l - e a n b e u s e d a s i m p e r v i o u s m a t s t o p r e v e n t w a t e n e n t e r l n g u n d e s l r e d l o c a t l c ; n s . A g o o d b u l l d e r u s e s h l s s o l I w l s e l y . I { e m a k e s & n e x t r a e f f o r t t o e o n s o r v e t o p s o l l n o t o n l y l n t h e i n t e r e s t s o f e o n s e r v a t i o n b u t a l s o t o ' p r e v e n t t h e e x p s n s o o f l m n o r t l n g t h i s n e c e s s e r y m a t e r l - a l . PBOPERTIES P r o p e r t l e s o f s o l 1 s w h i e h e a n b e u s e d t o i d e n t i f y s o l l t y p e s h a v e b e e n m e n t l o n e d . E a e h o f t h e s e s o l l t y p e s h a s p r o p e r t l e s w h i c h c a n b e p u t t o g o o d u s e l n c o n s t r u c t i o n w o r k . T h e f o l l o w i n g p r o p e r t l - e s a r e o f p a r t l c u l a r g e n e r a l l n t e r e s t . P e r m e a b l l l t y G r a v e l s a n d s a n d s a r e p o r : o u s a n d t h e r e f o r e p e r " m e a b l e t o w a t e r f l o w . S i l t s a r e m u c h l e s s p e r m e a b l e a r r d e l a y s a r e p r a c t l e a l l y l m p e r m e a b l e . T h l s p r o p e r t y 1 e o f m u c h s i g n l f l c a n c e l n t h e d e s t g n o f t l 1 e b e d s f o r t h e . d l s p o s a l o f s e p t l c t a n k e f f l u e n t . I t 1 s u s e l e s s l n e i t h e r o f t h e s e a p p l l c a t l o n s t o a t t e m p t t o d l s p o s e o f w a t e r i n a p u n e c l a y o r i n a n & r e & r , r h e r e t h e g r o u n d w a t e r t g b l e i s v e r y h l g h , A n y a t t e m p t t o d o s o w 1 1 1 b e u n s u e c e s s f u l . A k n o w l e d g e o f t h e p e r m e a b i l l t y a l s o g i v e s s o m e i d e a o f t h e d r a i n a g e c h a r a c t e r L s t i c s o f v a r i o u s s o i l s . C o m p r e s s t b 1 l l t y F o n m o s t m i n e r a . l s o l l s c o m p r e s s l b l l l t y l s n o t a p r o b l e m in the construction o f s m a l l b u l I d l n g s s u c h a s s i n g l e f a m l 1 y d w e l l t n g s . T h e p r e s e n c e o f o r g a n i e m a t t e r h o w e v e r i n d l e a t e s h i g h e o m p r e s s l b l l l t y . B e f o n e a n y s t r u c -t u r c l s b u i l -t o n t h e s e s o i l s a t h o r o u g h s o l l " q i n v e s t l g a t l o n s h o u l d b e c a r u i e d o u t . S t a b l l l t v I n h o u s e e o n s t r u c t i o n t h e b u l l d e r 1 s l n t e r e s t e d . l n : s o l 1 s t a b l l i t y e s i t a f f e c t s e x c a v a t l o n a n d t h e d e p t h t o w h l e h a p a r t l e u l a r s o l 1 m a y b o e x c a v a t e d w l t h o u t f a i l u r e o f t h e b a n k s . I t i s w e l l k n o w n t h a t s s n d s a n d g r a v e l s c a n h a v o o n l y a v e r y l l m l t e d v e r t l c a l e u t b e f o r e m a t e r i a l b e g L n s t o f e . I l i n t o t h e e x c a v a t i o n a n d a s g u m e s a n a t u r a l s l o p e . C l a y s r how-e v how-e r , c a n b how-e r c u t l n v e r t l c a l s l o p e s t o a c o n s l d e r a b l e d e p t h a n d , r m d e r o r d J . n a r y c o n d i t l o n s , r e m a l n s t a b l e f o r p e r h a p s t w o t o t h r e e w e e k s d e p e n d l n g o n t h e w e a t h e r , S l o p e s c a n a l s o b e c u t v e r t l c a L l y i n s i l t a n d t h e s l o p e s w 1 1 1 s t a n d f o n a
8
-m s . t e r l a l 1 s p o t e n t i a l l y t r e a c h e r o t r s o t o l n s t a b l l l t y r e s u l t l n g f r o m p r e c l p i
-llmlted. tlme but thls
f t 1 s v e r y s u s e e p t l b l e
t a t l o n a n d s e e p & g e .F r o s t A c t l o n
F r o s t a c t l o n m e y b e d e f l n e d a s e n y detrlmental e f f e c t o n t h e s o i l o r t h e s t r u c t u r e e s s o c L a t e d w l t h f n o c z ! . n g a n d t h a w l n g . f n s o r n e s o i l s , a s t h o f r o s t l 1 n c p e n e t r a t e s b e l o w t h e s u r f a e e , w a t e r L s d n a w n u p f r o m below'forrnlng h o r L z o n t a l l e n s e s o f p u r e l c e . T h l s p h e n o m e n o n r e s u l t s l n a . n u n e v e n h e e v l n g o f t h c s o l I s u r f e c e o w h e n t h e h e a v e d s o l l t h a w s , the w s t e r l n t h e l c e l e n s e s L s r e l a a s e d c r e a t l n g a v e r y u n s t a b l c s o l l c o n d l t l o n " r n t h e w o r s t e o n d l t l o n l t w i l l n e s u l t l n o l l q u l d s l u r r y o f s o l l a n d w e t o r " T h l s p h e n o m e n o n d o e s n o t o c c u n l n c l e a n s e n d s a n d g n a v e l - s but lt may prcsent a pnoblcm ln dtrty granulan materla1, The phcnomenon 1s most pronounccd l n s i l t y s o i l s . f t l s g e n e r a l l y n o t s e r L o u s i n e l e y s b u tf l s s u n e d c l e y s e a n h a v e e o n s l d e r a b r e h e a v l n g , f h e p r o b l o m o f f r o s t a c t l o n s h o u l d b o o f m u c h e o n e e r n t o the bul1den. r t a f f e c t s d r i v e w a y s a n d s h a l l o w footings.
M a n y c a s e s h a v e b o e n r e p o r t e d w h e r e unheatod b a s e m e n t s w e r 6 h o ' a v e d a n d craeked and evon destroyed. by f r o s t a e t i o n d u n l n g c o n s t r u c t l o n o A l s o c a s e s a r e k n o w n w h e r o t h e c x c a v a t l o n was done during cold weather, footings w e r e p l a c e d o n f r o z e n g n o u n d r e s u l t l n g l n s e r l o u s s e t t l e -ments when the ground flnally thawed"
plscussr0N 0F c01.w0N
BUILDTNG
PROBLEMS
1 . F r o s t A c t L o n
f n r e g l o n s w h e r e s e a s o n a l f r e e z l n g a l r t e m p e n a t u r e s o c c u r , f r o s t a e t l o n l n s o l l s l s u s u a l l y o n e o f t h e m a J o r p r o b r e r n s assoclated with bu{"ldlngo s o m e t y p i c * 1 r e s u l t s o f t h e e f f e c t o f f r o s t a c t i o n h a v e b e e n m e n t l o n e d " T h e s o l u t l o n t o t h e s e p r o b l e m s i s n o t u s u a l l y d l f f i c u l t . r f f o u n d a t l . o n s a r e b u l l t o n s o t l s u s c e p t i b l e t o f r o s t t h e f o o t l n g s s h o u l d extend to a depth lower than the maxlmum frost penetratlon otr t h o s u s c e p t i b l e m a t e r l a l s h o u l d b e r e p l e c e d . b y a n o n - h e a v i n g m a t e r l a l s u e h a . s e l e a n s e n d o n g r a v e l , F o r l l g h t s t r u c t u r c s t h e l o a d s c a n b e t r a n s m i t t o d b y s h o n t p o s t s t o a n e l e v a t l o n b e l o w f r o s t . A 1 I f o u n d a t i o n s m u s t n a t u r a l l y b o p r o t e c t e d f r o m f r o s t a e t l o n d u r S - n g construction a n d o f c o u r s e , no footlng s h o u l d e v e r b e p l e e e d on frozen ground. P e n h a p s o n e o f t h e w o n s t e f f e c t s o f f r o s t a e t l o n 1 s o n u n h e a t e d s l a b foundatlons, p a n t l e u l a r l y u n d e r a t t a e h e d g a r a g e s . r n t h l s c a s e t h e p o r t l o n o f t h e s l a b n e a r t h e h o u . s e d o e s n o t h e a v e d u e to heat loss from the house whlle the
p o r t l o n o f t h e s l a b f a r t h e s t a w a y f r o m t h e h o u s e r n a y h e a v e s e v e r a l i n c l r e s o r f t h e g a r a g e l s d l r e c t l y a t t a c h e d t o t h e
9
h o u s e w l t h o u t a b r e e z e w a y t h e f o o t l n g s m u s t b e d e e p e n e d t o e x t e n d b e l o w f r o s t p e n e t r a t l o n o r t h e f r o s t - h e a v l n g s o l l m u s t b e r e p l a c e d , H e a t l n g o f t h e f l o o r s l a b m a y p r e v e n t f u n t h e r d a m a g e b u t t h i s l s p r o b a b l y a n u n e e o n o m l e a l s o l u t l o n . I f t h e n e l s a b r e e z e w a y b e t w e e n t h e h o u s e a n d g a r a g e some sort o f f l e x l b l e c o n s t r u c t l o n m a y b e u s e d w h l c h w l 1 1 p e r m i t s i g n l -f l c a n t m o v e m e n t s o f t h e g a r a g e .2. BulLdlng o4 Fllled Ground
I f p o s s l b l e b u l l d l n g s s h o u l d n o t b e c o n s t r u e t e d o n f l l l e d g r o u n d " I f t h l s c a n n o t b e a v o l d e d , t h e s o l l s h o u l d b e p l a c e d s o t h a t t h e f 1 1 1 d o e s n o t s e t t l e . T h o s u r f a c e o f t h e f 1 1 1 s h o u l d - b e o b s e r v e d o v e r a p e r l o d o f t l m e t o e n s u r e t h a t t h e s o l l l s n o t s e t t l l n g . T h e b e s t t y p e o f s o l l t o u s e l n b a c k f l l l w 1 1 1 d e p e n d u p o n t h e d e s l r e d p n o p e r t t e s o f t h e backfll-l. For maximum eompactlon a clean sandy gravel wlth a w l d e v a r l a t l o n 1 n g r a l n s l z e i s b e s t . F o r g o o d p e r m e a b l l l t y g n a v e l s a r e b e s t , s a n d s n o t b a d ; s l l t s a n d c l a y s a r e p r a e -t i c a l l y l m p e r m e a b l e a n d a r e n o t s u l - t a b l e . I f f r o s t h e a v l n g 1 s a p o s s i b l l i t y , f i n e - g r a l n e d s o t l s m u s t b e a v o i d " e d . 3 . C o m p a c t l o n S e t t l e m e n t e a n b e p r e v e n t e d b y p r o p e r l y c o m p a e t l n g t h e b a c k f l I l " f h l s e a n b e d o n e s l m p 1 y , l n m o s t c a s e s , b y p l a c -l n g t h e s o 1 1 i n t h -l n -l a y e r s ( 4 t o 6 -l n e h e s ) a n d h a n d t a m p i n g e a c h l a y e r . I f t h e s o l l l s t o o d r y l t i s d i f f l e u l t t o c o m p a e t b e c a u s e o f f r i c t l o n b e t r s e e n t h e g r a l n s o T t , o n t h e o t h e r h a n d , t h e s o l l l s t o o w e t l t c a n n o t b e c o r n p a e t e d p r o p e r l y b e c a u s e t h e w a t e r w l 1 1 b e g l n t o d l s p l a c e m l n e r a l p a r . t l c l e s . W l t h m o s t s o l 1 s m a n i p u l a t l n g t h e s o l l b e t w e e n t h e f l n g e n s w 1 1 1 l n d l c a t e w h e t h e r t h e s o l l i s t o o d r y o r t o o w e t f o r g o o d c o m -p a c t l o n . W a t e r c a n t h p n b e a d d e d o r t h o s o l l m a y b e a l l o w e d t o d r y l n o r d e r t o p e r n r l t b e t t e r c o m p a c t l o n . 0 n l a r g e j o b s mechanlcal equl"prnent may be used but tfrls eannot normally
b e J u s t i f l e d f o r s m a l l o p e r a t i o n s , 4. Fallures of Foundatlo.n Walls
Foundatl,on walls fa11 frequently fo:: a variety of r e a s o n s o I n s o m e c a s e s f a t l u r e l s e a u s e d b y w a t e r p r e s s u r e s i g o o d d r a i n a g e ean prevent thls. S o m e f a i l u r e s o c c u r d u e t o b a c k - f l l I l n g b e f o r e a d e q u a t e b r a c l n g o f t h e f o u n c l a t l o n w a 1 1 h a s b e e n p r o v i d e d o r d u e t o t h e a d J a c e n t s u r f a c e l o a d l n g c a u s e d b y h e a v y c o n s t r u c t l o n e q u i p m e n t . T h e s e f a l l u r e s c a n b e p r e v e n t e d b y e n s u r l n g t h a t w a l l s a r e a d e q u a t e l y b r a c e d e i t h e r t e m p o n a r i l y o r b y f l o o r c o n s t r u c t l o n b e f o r e b a c k -f l t l l n g a n d b y k e e p l n g h e a v y c o n s t r u c t l o n e q u l p m e n t a . w a y f n o m t h e w a 1 1 f o r a d l s t a n e e a t l e a s t e q u a l to the depth of the waII.
T h i s b r i e f a c c o u n t o f e h a r a c t e r l s t l c s o f v a r l o u s s o t l t y p e s l s a n a t t e m p t to show that soll rshen understood and p n o p e r l y usod, ls not a constructlon h a z a r d b u t i s a v a l u a b l e b u l l d l n g m a t e r i a l .
1 0
-FOUNDATTONS
FOR HOUSES
b V D , C . T l b b e t t e
B u t l d l n g Practlce Constructlon Sectlon
M a n y o f t h e l n g u l r l e s r e c e l v e d b y t h l s D l v l s l o n h a v e t o d . o w l t h h o u s e foundatlonso 0 n 1 - y a f e w o f t h e s e w e r e p n o m p t e d by structrral f a l l u r e s ; t h o g r e a t m a J o r l t y w e r c r e l a t e d t o l e a l r y b a s e m e n t s a n d d a m p e r a w l s p a c € s .
I{o attempt w111 be made to foll-ow through thc s t e p s l n v o l v e d l n t h e c o n s t r u e t l o n o f h o u s e f o u n d a t l o n s beeause these are already known to you; hovrever, lt may be n e c e s s a r y f r o m t l m e to tlme to mentlon some constnrctlon
d e t a l l l n o r d e r t o d e s c r l b e s o m e o f the recommended procedures f o r p r o t e e t l n g t h e f o u n d a t l o n a n d s u p p o r t e d s t r u c t u r e s f r o m w a t e r a n d d a m p n e s s .
B e e a u s e l t 1 s d l f f l c u l t a n d s o m e t i m e s l m p o s s l b l c t o r e p a l r e x l s t l n g f o u n d a t t o n s t o a v o l d f u n t h e r d a m a g e , n e c e s s a r y p r e c s u t i o n s s h o u l d b e t a k e n d u r l n g e o n s t r u c t l o n when watenpnooflng and damp-proofing ean best be donc and a t t h e l e a s t c o s t o
S o m o o f t h e p r o b l e m s n e l - a t e d t o s o i l a n d s i t e c o n d l t l o n s s u e h a s s u r f a c e ' d r a i n a g e , e l e v a t i o n , a n d s o l l t y p e s a r e c o r n r n o n t o b o t h b a s e m e n t s a n d c r a w l s p a e e s .
P r o b l e m s t h a t a p p l y to only one true of foundatlon wlll b e d l s c u s s e d s e p a r a t e l y .
BASEMENTS
I t i s o f t e n s a l d t h a t d n y b a s e m e n t g a r e n o t d . e s i g n e d ; t h e y Just happen. f t 1 s o u r o p l n l o n , h o w e v e r , t h a t b a s e m e n t s can be deslgned uslng ordlnary materlali t h a t w 1 1 1 b e d r y uncler most condltlons. C a r e l n d e s l g n a n d . c o n s t r u c t l o n l s J u s t l f l e d b e c a u s e o f t h e h i g h c o s i o f r e p a l r l n g l o a k y b a s e m e n t s . D a m p n e s s m a y a p p e a r ln three forms: l e a k a g e , c a p l l l - a r l t y , a n d c o n d e n s a t t o n . T h e s e m a y o e c u r s e p a r a t e l y o r s i m u r t a n e o u s l y b u t m a y b e s e p a r a t e l y l d e n t l f i e d . u s u a i l y c a p i l l a r i t y a n d l e a k a g e o c c u r l n s p r l n g w h i l e eondensatl-on ls none commonly a suiltmer condltion.
( 1 ) L e a k a g e w 1 1 1 b e a p p a r e n t b y the presence of free water o n t h e l n n e r s u r f a e e s o f w a 1 1 s a n d f l o o r s . I t l s c a u e e d b y f r e e w a t e r o n t h e o u t s l d e o f w a l l s a n d b e n e a t h f l o o r s f l n d i n g 1 t s w a y t h r o u g h p o r o u s c o n c r e t e o r r n a s o n r y ,
c r a c k s , a r o u n d s e r v l e e p i p e s , o r t h n o u g h i r n p e r f e c t w a t e r -p n o o f e o a t i _ n g s ,
. 1 1
-{ 2 ) c a p i l l a r l t y r e s u l t s i n d . a m p s p o t s w h e n e v a p o r a t i o n o f w a t e r a t t h e i n s l d e s u r f a c e s o f w a l l s a n d f l o o r s i s n o t
g r e a t e n o u g h t o d i s s l p a t e t h e w a t e r t o t h e a i r . S o m e -t i m e s -t h e s o u r e e o f m o l s -t u r e l n b a s e m e n -t s l s n o -t r e a d . -t l y g p p a r e n t in that the surfaces of warls and floors appear d r y ' . T h o m o l s t u r e m a y b e d u e to eapillarlty b u t O a m p s p o t s a r e n o t e v i d e n t b e c a u s e t h i s m o l s t u r e e v a p o r a t e s a t t h e s u r f a c e a t a rapld rate and load,s the atr with m o l s t u : : e . _ A n e a s y w a l t o c h e c k f o r m o l s t u r e c a u s e d b y t h e c a p i l l a r l t y i s t o c o v e r a n a r e a l o i t h a rubber mat-f o r a mat-f e w d a y s , t h e n o b s e r v e t h e c t i n d i t i o n s u n d e r t h e m a t . r f t h e c o n c r e t e s u r f a c e u n d e r : the rnat or the back o f t h e m a t l s r , u e t then caplllartty 1 s t a k i n g p l - a c e . c a p i l l - a r l t y i s m a c e p o s s i b l e b y t h e l n t r m a t e c o n t a c t o f a n a b s o r b e n t m a t e r i a l ' ^ r l - t h danp earth on water, the m o i s t u r e b e l n g d r a w n through ilre mas;onry by capillary a c t i o n m u c h the same as a wlck nill s o a k u p w a t e n . ( 3 ) O o n d e n s a t l o n w 1 1 1 o c c u r o n w a l l s a n d f l o o r s r . r h o n th e
h u : n l d i t y i n t h e b a s e m e n t i s h l g h a n d the air temperatu:,e a n d r e l a t i v e h u r a i d l t y o f t h e o u t s i d e a l r a r e arso h1gh. c o n d e n s a t l o n l s c a u s e d b y m o i s t u r e i n t h e a i r c o m i n g i : : e o n t a c t w i t h t h e relatlvely c o o l e r r " . r a l } s a n d f l o o r s r v h - L c h r n a l n t a j . n a t e m p e r a t u r e e l o s e t o t h a t o f t h e a d j a c e n t s o i 1 . A c h e c k t e s t f o r c o n d e n s a t l o n c a n b e m a c e b y c S v e r i n g s u s p e c t e d a r e a s w i t h g l a s s o r s h e e t m e t a l . w a t e r o n t h e e x p o s e d f a c e o f t h e s e m a t e r l a l s i n d i e a t e s t h a t c o n d . e n -s a t i o n l -s t a k i n g p l a c e o n t h e w a 1 1 -s o r f l o o r -s . T h e c h l e f c a u s e s o f l e a k a g e a n d c a p l l l a r l t y a r e i n a d e q u a t e d r a i n a g e a n d i n f e r i o r c o n s t r u c t l o n . Surface Drainage E a v e s t n o u g h s a n d d o w n s p o u t s should be provlded. T h e l o e a t i o n o f t h e d o w n s p o u t s i s i m p o r t a n t : t h e y s h o u l c . b e c o n -n e c t e d t o u -n d e r g r o u -n d d r a t -n s o r d l s c h a r g e d i -n t o l e a d s w h l c h w i l l c a r r y t h e w a t e r arda)J f r o m t h e f o u n d a t l o n v r a 1 1 s . T h e l e a s t t h a t s h o u l c l b e d o n e is to provi-d.e extensions cti::ected. a w a y f r o m t h e b u i l d i n g i n s t e a d o f s t r a i g h t d o w n . r n n o c a s e s h o u l d r J . o w n s p o u t s bo c{)nnected. to the drain tlIe a r o u n d t h e f o o t l - n g s .
T h e b a c k f i l l a n d t o p s o l l a t g r a d e l i n e s h o u k l be s l o p e d a w a l r f r o m the walls to assist run-off a n d t o p r e v e n t p o n d i n g o f w a t e n a t o r n e a r t h e o u t s L d e f a c e of the wa1l. S u b s u r f a c e D r a i n a g e
t2
surfaee dralnage are teken, some water w111 enter the ground and lt ls not uncommon for the groundl+ater tabl_e to be at an e l e v a t i o n a b o v e t h e f o o t l n g l l n e o T o r e l l e v e t h i s s i t u a t i o n , d r a l n t l l - e s a r e p l a e e d a r " o u n d the outslde of the penlmeten f o o t i n g s . D r a l n t l 1 e , w h e n p r o p e r l y l n s t a l l e d , a r e e f f e c t l v e f o r o t h e r , t h a n o x t r e m e c o n d l t l o n s s u e h a s l n l o w a r e a s a n d o n s l t e s r ' r h e r e t h e w a t e r t a b l e a n d sol1 percolatlon r a t e a r e h l g h f o r p r o l o n g e d p e r l o d s " T t l e s s h o u L d . b e l o c a t e d a l o n g s l d . e t h e f o o t l n g a n d n o t o n t o p o f l t a s i s s o m e t l m e s d o n e . T h e y m u s t b e s l o p o d t o w a r d s a s u l t a b l e o u t l e t , T h e r e c o m m e n d e d s l o p e f s * lnch i n 1 2 f e e t . T h e t l l e c o m m o n l y u s e d s h o u l d b e s p a e e d a b o u t f l n c h ; t h l s j o l n t s h o u l d b e c o v e r e d o n t o p w l t h b u l l d i n g p a p e r r t o p r e v e n t s o i l p a r t l c l e s e n t e r l n g a n d c l o g g i n g t h e t l l e . T h e t l l e s h o u l d b e c o v e r e d w i t h c o a r s e g r a v e l o n o t h e r g r a n u -Iar material to a mlnlmum depth of 12 lnches.
T l l e s h o u l d . b e e a r e f u l l y p l a c e d . B r o k e n o r c r a c k e d t l I e s h o u l d n o t b e u s e d a s t h e y w 1 1 1 c a u s e b l o c k l n g . T l I e a r e u s e L e s s u n l e s s o u t l e t s a r e p r o v l d e d . w i t h o u t a n o u t l o t t h e y m i g h t a s w e l l b e l e f t o u t a s t h e y a r e t o o e x p e n s l v e a s b a c k f l l l a n d w o u l d s e r v e n o o t h e r p u n p o s e . O u t l e t s c a n r e a d i l y b e p r o v l d e d w h e r e s t o r m s e w e r s a r e a v a l l a b l e b u t i n r u r . a l a r e a s l t i s s o m e t l m e s d i f f l c u l t t o f l n d s u l t a b l e o u t l e t s .
D r y w e L 1 s a r e u s e d t o a d v a n t a g e v r h e r e the slte and s o l l e o n d l t l o n s a r 6 s u l t a b l e . 0 n s l o p i n g l o t s t h e y c a n b e u s e d p r o v l d e d t h e t o p s o l l 1 s r e l a t l v e l y i m p e n v i o u s a n d t h e s u . b s o i l f a l n l y a b s o r p t i v e . D r y w e 1 1 s s h o u l d n e v e r b e used in 9 1 a y a s t h l s m a y r e s u l t l n p o n d i n g o f w a t e r a r o u n d t h e f o o t l n g s . Roof dnalnage should not be canr'led to the safle dry well
p r o v l d e d f o r t h e f o o t l n g t l l e "
Draln tile can often be L+c.d. to open dltches on s l o p i n g l o t s .
O n 1 e v e l s l t e s t h e o n l y s u l t a b l e a l t e r n a t l v e t o o u t l e t s t o s e w e r s l s t o l e a d t h e t l l e t o a s u m p p l t w i t h i n the house from where lt ean be pumped up and out to a locatlon s o m e d l s t a n c e from the found.atlon.
T h e r e a r e s e v e r a l f a c t o r s c o n t r l b u t i n e t o l - n f e r l o r c o n s t r u c t i o n . ( 1 ) I n a d e q u a t e f o o t l n g s e a n r e s u l t i n s e t t l e m e n t t h u s c a u s l n g e n a c k i n g l n w a l l s a n d s e p a r a t l o n e t t h e Junctl"on of the f l o o n a n d w a 1 l . C r a e k s h a v e o c c u r u e d w h e r e t h e p e r l m e t e r f o o t l n g s w e r e a d e q u a t e b u t n o p r o v i s l o n w a s m a d e for the s u p p o r t o f l n t e r l o r l o a d - b e a r l n g w a 1 1 s . B e s i d e s e a u s l n g movement ln the supported structure, rupturlng of the e x t e r l o r " w a l 1 m a y o c c u r if the two walls ar6 of masonny b o n d e d t o g e t h e r .
1 3
-F o o t i n g s s h o u l d b e d e s l g n e d f o r s p e c l a l condltlons a n d r e l n f o r c e d i " r h e r e n e c e s s a r y ln accordance with Local code r e q u l r e m e n t s . f f n o c o d e e x l s t s b u t l t i s k n o w n f r o r n p r a c t l e e t h a t y o u a r e b u l l d l n g o n p o o r s o L 1 , t h e f o o t -l n g s s h o u -l - d b e s p r e a d o v e r g n e a t e r areas and stee-l n e l n f o r e e m e n t a d d e d . F o r m o s t c o n d L t l o n s a r u l e o f -thumb d.eslgn call-s fon the Cepth of footlng to equal t h e w a l l t h l c k n e s s a n d t h e w l d t h o f f o o t l n g t o e q u a l t w l e e t h e w a l l t h l o h e s s ,
N o f o o t i n g s s h o u l d b e a r o n n e w b a c k f l I l . I f l o w ar?eas exist Ln the excavatLon, use more concrete or a. s t e p p e d f o o t i n g s o t h e f o o t l n g w i l l b e l n e o n t a c t w i t h t h e u n d l s t u r b e d s o l l .
F o o t l n g f o r m s s h o u l d not be filled w i t h n o c k t o w i t h l n a f e w l n c h o s o f t h e top and covered. vrlth a thln
s h e l l o f c o n c r o t e . I t t s e q u a l l y p o o r p r a c t l c e t o u s e n s o u p y R concrete. S u c h f o o t l n g s " w i l l b - e w e a k a n d r s 1 1 l c r a c k r r n d e r l o a d , eauslng craeks ln the foundatlon walls. C 1 e a n , s t n o n g r o c k c a n b e u s e d l n f o o t l n g s l f s p a c e s a r e L e f t b e t w e e n t t r e r o c k s a n d between the forms ane the rocks. T h e c o n e n e t e s h o u l d b e tamped so that it is foreed lnto these s p a c e s a n d p r o v l d e s a p r o p e r bond. F o o t l n g s s h o u l - d b e L e v e 1 , e s p e c l a l l y w h e r e e o n c r e t e b l o c k s a n e used, to ensure uniformlty o f m o r t a r J o l n t s . ( 2 ' ) f m p e r f e c t l y l a i d m a s o n r y w i t h i n a d . e q u a t e l y , f l l l e d a n d p o o r l y c o m p a c t e d m o r t a r j o i n t s r e s u l t s l n w e a k w a l 1 s a n d s u b s e q u e n t c r a c k l n g a n d l e a k a g e . B l o c k s s h o u L c l b e l a l d t r u e w i t h a l l h o r l z o n t a l j o l n t s a n d v e n t i c a l e n d j o i n t s f i l I e d w l t h m o r t a r . S t a r t i n g a t t h e f o o t i n g , t h e f l r s t c o u r s e s h o u l d b e 1 a i d ln a fuLl mortar bed. M o r t a r Jolnts should be ZIB to t/Z inch thlck and compacted after ttre m o r t a r h a s s t i f f e n e d ,
Variou.s mortar mlxes can be used but eement should be l n c l u d e d l n t h e m l x f o r w a l l s b e l o w g r a d e . s o n e s u L t a b r e n i x e s a r e :
1 : * ' ; 3
C e m e n t
: l i m e p u t t y : s a n d
I . t . A t t t t $ r t+ a 4 . v
( 3 ) c a _ s t - 1 n - p l a c e w a l l s of 1ean, poorly mlxed concrete Lmprop-e n l y p l a c Lmprop-e d a n d c u r Lmprop-e d can bLmprop-e Lmprop-expLmprop-ectLmprop-ed to craLmprop-ek and ILmprop-eak. G o o d c o n c r e t e p r o p e r l y p l a c e d has a hlgh reslstance t o n a t e r e n d l s m a d e wlth the same materlals a s p o o r L e a k y
c o n c r e t e . ( l | ) t r ' a l l u r e t o p r o v l d e w a t e r t l g h t J o i n t s b e t w e e n t , h e w a 1 1 a n d . t h e f l o o n o f t e n r e s u l t s l n l e a k a g e a t t h l s p o l n t . ? h e D l v l s i o n o f B u l l d l n g R e s e a n e h h a s h a d a n u n r t e n o f requests f o r l n f o r m a t l o n o n h o w t o r e p a l r c r a c k s w h l c h o c e u r a t the junctlon of the floor and walr and throueh which
i l +
-w a t e r leaks lnto the basement. ft ls recoslmended
t h a t
a s p a c e be left between the edge of the floon of $ to -t
l n c h w h i c h is fiLled r*i-th bitumlnous materlal after the
c o n c r e t e floon has hardened and cured.
I n a d d l t l o n a
m o r t a r cove should be pnovlded on the exterior slde of
the wal} at the Junctlon of tho wall and the footlng.
( 5 )
A d e q u a t e damp-proofing of the extertor of foundation walls
s h o u l d be provlded.
W h e n conereto blocks are used the
e x t e r l o r of the wa11 should be plastered before bltuminous
c o a t i n g s a r e a p p l i e d .
T h l s p l a s t e r s h o u L d b e a c e m e n t : s a n d
m l x l n t h e p r o p o r t l o n s of l:2* or 1:3 and should be
sur-f a c e d r X r to necelve the bltumLnous coatLngs.
Bltr;mlnous materl-als comnonly used ane brush-appi-Led.
bltumlnous eutbacks and brush-applled
asphalt erruIslons.
T h e s e a r e n o t t h e b e s t t y p e s t o u s e , m o r e s a t l s f a c t o r y
r e s u l t s w i l l be obtalned wlth hot asphalt or coal tan
p L t c h , or trowel coati.ngs of bltumen wlth solvent s.
B e c a u s e the poorera types of bltumlnous materLal are
com-monly used, good worlmanshlp is of prlme funportanee and
t t l s s u g g e s t e d t h a t t w o o r t h r e e e r i s s - c n o s s c o a t s b e
a p p l L e d .
B a c k f l l l l n g
s h o u l d not be done untll
t h e
coat-lngs are dry and then care should be exerelsed to ensure
that they are not damaged.
P l a s t e r l n g 1s not requlred on concrete walls unless the
c o n c r e t e ls very porous and full
o f v o l d s t o the extent
that lt worrl-d provide an unsuitable
surface for
bltum-l n o u s coatbltum-lngs.
T h e a p p l l c a t i o n o f b t t u m l n o u s c o a t i n g s s h o u l d b e c a n r l e d o u t a s f o r c 6 n c r e t e b l o c k w a I 1 s .
C a p i l l a r i t y t h r o u g h f l o o r s c a n b e p r e v e n t e d b y a g r a v e l u n < l e r l a y unless, of course, water ls in Cirect c o n t a c t w t t h t h e u n d e r s l d e o f t h e s l a b . S i x l n c h e s o f graveL or other gr"anular materLal ls the recommended t h l e k n e s s b e n e a t h b a s e m e n t f l o o r s . f f f l o o r c o v e n l n g s a r e t o b e u s e d o n the basement floon whether those be p a l n t , t l I e o n w o o d , l t i s w e l l t o l n s t a l L a l a y e r o f 55-)-U. roIled rooflng between the gnave} and the slab. T h l s w l 1 1 p r e v e n t c a p i l l a r i t y l f w a t e r r l s e s t k r r o u g h t h e granular undeni-ay and in addltlon will offer good resls-tance to the movement of water vapour through the sLab from the earth beIow.
WATERPROOFTNG
l { h e n e c o n d l t l o n s a r e s e v e r € , t h e n l t L s n e c e s s e . r y t o c a m y o u t a m e m b r a n e treatmont to both walIs and floors.
1,5
-Thls membnane of aLtornate layers of hot tar and tar
p a p e r or hot asphalt and asphalt papers should be as
contLn-uous as posslbl-e frorn a polnt above grade down the wall- and
u n d e r the flooro
F o n m e m b r a n i n g t h e f l o o r , t w o l l f t s o f c o n c r e t e a r e u s e d t o a d v a n t a g e . O n e t o p r o v l d e a 1 e v e l s u r f a e e f o r membrane appl-lcatlon and one on top of the membrane to provlde t h e s t r u c t u r a l s l a b a n d w e a r t n g s u r f a c e .
W a t e r p r e s s u r e c a n b e s e v e r e a n d w h e r e h e a d s o f 3 o r 1 4 f e e t o f w a t e n o c e u r , t h e n e e d f o r s l a b r e L n f o n c e m e n t should be consldered to prevent Cnacklng and subsequent leak-l n g . S o m e o f t h l s p r e s s u r e c a n b e r e l i e v e d b y u n d e r f l o o r drains leadlng to a sump plt,
CONDENSATTON
Condensation eommonly occurs on the walls and plumb-l n g s e r v plumb-l c e s i n b a s e m e n t s b u t m a y b e e l l m i n a t e d o r a t l e a s t m a t e r l a l l y r e d u c e d b y v a r i o u s m e a n s . ( 1 ) V e n t l l a t l o n w i l - 1 p r e v e n t c o n d e n s a t l o n p r o v i d . e d t h e a i n i n t r o d u c e d l s d r y . V e n t i l a t l o n l n s u r ? r m e r l s n o t u s u a l l y s a t l s f a c t o r y s i n e e t h e r e l a t t v e h u m i d l t y o f t h e o u t s l - d e a i r i s o f t e n h i d t a n d r e s u l t s i n m o r e e o n d e n s a t l o n o n e o o l b a s e m e n t s u r f a e e s . T h e b a s e m e n t s h o u l d n o t b e v e n t -ll-ated on warm humld days.
( 2 , B y r a t s l n g t h e t e m p e r a t u r e o f t ' n e a l r i n b a s e m e n t s t h n o u g h h e a t l n g , t h e c a p a c l t y o f t h e a l r t o h o l d w a t e r l s l n c r e a s e d , the ternperature of surrorrndlng su.nfa.ces is usuelly ralsed above the dewpolnt and. any small amount of dampness d.ue t o c a p l l l a r l t y 1 s r e a d " l l y a b s o n b e d b y t h e a i r .
( 3 ) I n s u l a t l - o n u s e d a b o v e g r a d e w 1 1 1 r e d , u c e o o n d e n s a t L o n occurr:lng on the lnsLde of the ba.sement nrall, Vapour b a r u i e r s s h o u l d b e u s e d t o p r o t e c t t h e l n s u l a t l o n a n d w h 1 l e t h e l n s u l a t l o n u s u a l l y n e e d o n l y b e c a r r l e d d o w n
about four feet from the top of the waI1, the vapour b a r r l e r s h o u l d b e c a r u l e d d o w n t o f l o o r 1 e v e l . P l p e
i n s u l a t L o n w h e n p : : o p e r . l y p r o t e c t e d b y a v a p o u r - p r o o f e o v e r i n g w l 1 1 p r e v e n t e o n d e n s a t l o n "
( h ) C o n d e n s a t l o n e a n b e p r e v e n t e d by removlng molstu::e from the aln; thl s lowers the dewpoi-nt below the temperature o f t h e w a l L a n d f l o o r s u r f a c e s . F o r d e h u m l d i f l e a t l o n t o b e e f f e e t l v e , d o o r s a n d w ! . n d o w s s h o u L d n o r m a l l y b e e l o s e d . f f l a u n d e n l n g l s d o n e l n t h e b a s e m e n t a n d e l o t h e s a r e d r l e d o n l i n e s o r i n f o r c e d d r i e r s , t h e h u m l d l t y w t l I l n e r e a s e g r e a t l y a n d d e h u m l d l f l c a t l o n w i l l b e d l f f l c u l t . D u r i n g t h e s e o p e r a t l o n s , d o o r s a n d w l n d o w s m a y b e o p e n e d t o d i s s l p a t e t h i s e x e e s s o f m o l s t u r e t o t h e o u t d o o r s .
15
T h e n e a r e t u o b a s i c t y p e s o f d e h u m l d t f l c a t l o n :
( a ) T h e c h e m l c a l t y p e w h i c h depends on the abllity o f m a t e r l a l s u s e d t o a b s o r b m o l s t u r e frorn the alri a n d ( b ) T h e m e c h a n l c a l t y p e s w h l e h operate on the princlple
o f e o n d e n s l n g t h e m o i s t u r e o n c o o l e d e v a p o n a t o n b o l l s . T h e c h e m l c a l s e o n r n o n l y used are ealclum chlorlde a n d s 1 1 -l c a g e 1 . T h e c a l c l u m c h l o r l d e t s r e r a t l v e l y l n e x p e n s l v e b u t t t c a n b e used only once and must be dliposed- of when L 1 q u l d . t h e s o l u t l o n i s s o m e w h a t h a r m f u r t o c o n c r e t e
a n d v e g e t a t l o n a n d w h e n l n l t s c o n e e n t r a t e d . form wllr n e a d l l y c o r r o d e s t e e l . f f d l s p o s e d o f i n a d r a l n , i t s h o u l d b e w a s h e d d o w n wlth quantltles o f w a t e r .
S l l l c e . g e l m a y b e used and ne-used. B y r e h e a t t n g t h e S 9 1 , t h e w a t e r l s d r l v e n o f f a n d i t r e g A , l n s t t s a U s o r p -t l v e p o w e r . CRAb/L $PACES A c r a w l s p a e e i s t h a t e n e l o s e d s p a e e u n d e r t h e f l r s t f l o o r o f a b u l l d l n g w h e r e t h e r e 1s no basement or occupancy a n d t h e f i r s t f l o o r i s s o n e c l i s t a n c e a b o v e t h e surface of ifre ground.
[ h i s s p a c e m a y o n l y b e a foot or two htghr o? sev-e n a l f sev-e sev-e t in hsev-elght. T h e w a l r s r n a y b e m a s o n r y or-they nay b e s o n e form of iheathing materlal- supponted. bn 11ght" fnartlng.
N o m a t t e r w h a t t h e d e t a l l s a r e t h e r e s u l t i s a n e n e l o s e d area whlch can be a constant supply of moisture and t h e r e f o r e , p o t e n t l al troubl.e,
s u r v e y s h a v e b e e n made whlch tndtcate t h a t c r a w l s p a c e s a r e lmmedlately assoeiated wlth terms such &sr damp-n e s s r r o t t l damp-n g _ o f h . u l b e r , r u s t t n g c f s t e e r , m u s t y o d o u r s , * d
g e n e r a l unhealthy eondl_tlons.
T h e e & u s e o f a l l thls trouble wtrth cr-awr spaces can b e a t t r l b u t o d t o m o l s t u r e i n L n a d e q u a t e l y ventirated. spac6s.
T h e r e h a s b e e n s o m e measure of success in corneeting t h l s s l t u a t l o n b y v e n t l l a t i o n a n d t h e r e a r e c e r t a l n r e c o m m e n d -a t l o n s f o r t h e r e q u l r e d l o e -a t l o n -a n d s t z e c f v e n t s . T h e t o t a L net amount of venttlatlon for the average b.ungalow, 24 by l+o f e e t l s a p p r o x l m a t e l y 6 s q u a r e f e e t . r f t / t 6 - t n c h m e s h l s u s e d . f o r t h e s e o p e n l n g s then the opening to be mado in the wall wlrl b e t w l c e t h l s .
A t l e a s t l . r o p e n i n g s should be used, one near each c o r n e r o f t h e building a n d t h e y s h o u l d b e p l a c e d as hlgh ae
