How long should roofing nails be for shingles?
By shingle type
- 3-tab: thin single layer, so 1 1/4 inch is plenty on standard decking.
- Architectural (laminated): two bonded layers at the nailing area. 1 1/4 inch still works on 7/16 or 1/2 inch decking.
- Designer and luxury shingles: thicker multi-layer pieces. Many manufacturers call for 1 1/2 inch or longer.
- Impact resistant shingles: often thicker and heavier, so follow the length printed on the wrapper.
- Hip and ridge caps: the cap wraps over the peak and covers field shingles, so 1 3/4 to 2 inch nails are typical.
Placement matters as much as length
Architectural shingles have a marked nailing strip, usually a painted line or a textured band. Nails must go through that strip so they catch both layers of the shingle and the top edge of the course below. Nails placed too high miss the lower course and let shingles slide or blow off. Nails placed too low show in the exposed area and leak. Each nail should be driven straight and flush, not sunk into the mat and not left raised.
How many per shingle
Four nails per shingle is the code minimum for strip shingles. Many manufacturers require six in high wind areas, on very steep slopes, or for their stronger wind warranties.
Material
Use galvanized, stainless, aluminum or copper roofing nails with at least a 3/8 inch head. Bright framing nails rust and stain the roof.
Compare shingle styles in architectural vs 3-tab shingles and impact resistant shingles in Georgia.