240 SHINGLING. 
shingle will make a leaky one. If first-rate shingles 
are employed, and one poor one is worked in among 
every 100, that roof might about as well have been 
without any shingles. If any poor shingles are to be 
used, let them all be laid together near the upper part 
of the roof. The best of shingles will not make a tight 
roof if they are not properly laid, while the same shing- 
les would make an excellent roof if laid as shingles 
should be laid. : 
The correct rule for laying shingles of any length, 
in order to form a roof leak-tight, is to lay the courses 
less than one third the length of the shortest shingles. 
For example, when shingles are 18 inches long, many 
of them will not be more than 17 inches in length. 
Therefore five inches is all that the course will bear 
to be laid to the weather with surety of forming a 
good roof. The shingles must be three thicknesses 
over the entire roof. If they are not three thicknesses 
—if now and then a shingles lack a quarter or half 
an inch of baing long enough to make three thick- 
nesses—there will in all probability be a leaky place 
in the roof at such a point. Moreover, when the lower 
courses lack half an inch of extending up far enough 
to receive the rain from the outermost course, in 
case the middle course were removed, it would be just 
as well to lay them seven or eight inches to the 
weather as to lay them only five, or five and a-half, 
inches. Many shingles are only 16 inches long, and 
many that are sold for 16 inches long will hardly 
measure 15 inches. In this case—if the roof be rather 
flat, say about one quarter pitch—four and a-half 
inches is as far as they should be laid to the weather. 
In case a roof were quite steep it might answer to lay 
the courses four and three-quarter inches to the weather. 
When buildings are erected by the job, proprietors 
should give their personal attention to this subject. 
and see that jobbers do not lay the courses a half 
inch too far to the weather. 
There is another important consideration which is 
too frequently overlooked in shingling, which is break 
ing joints. Careless workmen will often break joints 
within half an inch of each other, when the joints 
of the different courses come so close together, the 
roof will most certainly leak. Why should it not? 
There is nothing to prevent it during a heavy rain. 
Unless a roof is steeper than a quarter pitch much 
care should be taken to break joints not less than 
one and a-quarter inches. Let all workmen and help- 
ers be taught the vast importance of rejecting every 
poor shingle, except when the upper courses are being 
laid.—Canadian Mechanics’ Magaatne. 
