Page 151 - 2018 National Home Improvement

2018 National Home Improvement Estimator, All Rights Reserved Page 125

Install 15-pound saturated felt before laying asphalt shingles on a roof with a 4 in 12 to 7 in 12 pitch.
Start by laying the felt at the roof eave and lap each successive course by several inches. Stagger the
felt courses to separate joints. Apply a double layer of 15-pound felt on a roof with less than a 4 in 12
pitch. Doubling the felt will take more time because it’s harder to keep wrinkles out.

Begin application with metal edging along the eave line. Cut the exposure tabs off the first course of
asphalt shingles and lay them along the roof edge. See Figure 7-4A. Then apply another course on top
of the first, extending the shingle exposure 1/2" over the metal edging at the rake to prevent water from
backing up under the shingles (Figure 7-4B). Apply the next course with the recommended exposure.
Snap horizontal chalk lines on the felt to help keep shingles in straight lines. Follow the manufacturer's
recommendation on nailing. When a nail penetrates a crack or knothole, remove the nail, seal the hole,
and drive another nail into sound wood. Any nail that doesn’t hit sound wood will gradually work out and
cause a hump in the shingle above. Use seal-tab or T-lock shingles in high wind areas.