What is the nailing pattern for architectural shingles?
Short answer. Architectural shingles are normally fastened with four nails per shingle, placed in the manufacturer's marked nailing zone so each nail goes through both laminated layers and the shingle below. Some manufacturers call for six nails on very steep slopes or for certain wind ratings, and the bundle wrapper shows the exact positions.
The basics
- Count: the residential code requires at least four fasteners per strip shingle, or more if the manufacturer says so. A standard square of a common architectural shingle uses 64 pieces and 256 nails.
- Location: in the nailing zone, a band printed or textured across the shingle. On laminated shingles, nails must catch both layers where they overlap.
- Spacing: one near each end and the others spread across the middle, matching the diagram on the wrapper.
Nail specifications
The code calls for galvanized steel, stainless steel, aluminum or copper roofing nails with at least a 12 gauge shank and a 3/8 inch head, long enough to go 3/4 inch into the deck or all the way through thinner decking.
Placement mistakes that cause blow offs
- High nailing: above the zone, the nail misses the shingle underneath, so each shingle is held by fewer nails than intended.
- Low nailing: below the zone, the nail can show or sit in the path of water.
- Overdriven nails: the head cuts into the mat. Common when nail gun pressure is set too high.
- Underdriven or crooked nails: raised heads keep the shingle above from sealing.
Six nail situations
Very steep roofs, above roughly 20/12, require special fastening, typically six nails plus hand sealing per the manufacturer. Some enhanced wind ratings also specify extra fasteners or particular accessories.
Why it matters to you
Nailing is hidden once the next course goes on, and manufacturer warranties exclude installation errors unless an enhanced warranty covers workmanship. Ask how the crew checks nailing. See roofing warranties explained and wind damage to roofs in Georgia.