Shingles are generally put on by the carpenter, although in the larger cities there are persons who make a specialty of shingling roofs; but it is doubtful if, as a rule, they do the work as well as a regular carpenter.

The men that put on the shingles also usually do all flashing, except counter flashing, and the flashing material is ordinarily furnished by the tinner.

In shingling a roof the workmen always commence at the eaves, or lowest edge, and lay the shingles in courses, either to a line or straight-edge. The first or lowest course should always be a double or triple one (usually double); the other courses are laid single. Each shingle should be secured by two 3-penny nails, driven about 8 inches from the butt, and if a very durable roof is desired galvanized nails should be used. (Cedar, cypress or redwood shingles will usually remain in good condition long after the nails have been destroyed by rust.)

The courses of shingles should lap over each other so that a little less than one-third of the length of the shingle will be exposed to the weather.

Unless the roof is very steep 16-inch shingles should not be laid more than 4 inches "to the weather," nor 18-inch shingles more than 5 inches to the weather.

Of course the more the shingles are laid to the weather the greater area a thousand shingles will cover, and hence it is to the contractor's advantage to lay them as much to the weather as he thinks is safe; for this reason the specifications should always state how much of the shingle is to be exposed.

The following table shows the area that 1,000 shingles (random widths) will cover when laid with different exposures, allowing nothing for waste:

Laid

4

inches

to the weather,

1,000

will cover

118

sq. ft.,

or

847

to a

"square."

"

4

"

"

"

"

125

"

or

800

"

"

"

4

"

"

"

"

131

"

or

758

"

"

"

5

"

"

"

"

138

"

or

720

"

"

"

5

"

"

"

"

152

"

or

655

"

"

"

6

"

"

"

"

166

"

or

600

"

"

This table, of course, applies to either walls or roof. The shingles in the different courses should be laid so as to break joint at least 1 inch, and as much more as possible. They should not be laid too tightly together, as this will make them bulge when they become wet.

130 Laying The Shingles 200104

Fig. 168.

Fig. 169.   Ridge Cresting.

Fig. 169. - Ridge Cresting.