Asphalt Shingle Application and Fastening
Asphalt Shingle Application and Fastening
This domain tests correct slope limits, starter and course layout, exposure control, and fastener placement for 3-tab and laminated shingles.
Core rules
- Asphalt shingles are not approved below 2:12. From 2:12 to 4:12, install double underlayment and follow the manufacturer; above 4:12, normal underlayment applies.
- Install starter strip at eaves and rakes. Offset succeeding courses so side seams do not align; a common stagger is 6 in., with end joints offset per manufacturer.
- Set exposure with a gauge: 3-tab shingles commonly use 5 in.; laminated shingles often use 5 5/8 in. Follow the bundle.
- Use roofing nails of 11 or 12 gauge with 3/8-in. heads, long enough to penetrate 3/4 in. through the deck. Standard is four nails per shingle; high-wind areas require six, placed on the nail line about 1 in. above the exposure line, with heads flush.
- High or overdriven nails reduce wind resistance and can tear shingles.
Worked example
A 3-tab shingle is 12 by 36 in. at 5-in. exposure. Coverage per shingle is 5 × 36 = 180 sq in.; 14,400 sq in. per square ÷ 180 = 80 shingles per square. At four nails each, that is 320 nails per square; at six nails, 480. This is why nail-count checks matter in wind zones.
Traps
High nailing, overdriving, using four nails where the wind rating calls for six, skipping starter, and changing exposure mid-roof are common failures.