What is the standard roofing nail size?
The four parts of size
- Length: 1 1/4 inch is standard for shingles. Roofing nails are sold by length in inches, not by the penny system used for framing nails.
- Shank gauge: a smaller gauge number means a thicker nail. 12 gauge is about 0.105 inch, 11 gauge about 0.120 inch.
- Head diameter: 3/8 inch is the minimum; many nails have 7/16 inch heads for extra pull-through resistance.
- Shank type: smooth is common; ring shank grips better and resists backing out.
Material and coating
The IRC calls for galvanized steel, stainless steel, aluminum or copper roofing nails, and points to the ASTM F1667 nail standard. Electro-galvanized is typical for inland shingle work; hot dipped galvanized has a heavier zinc coating for harsher exposure.
Reading a box label
A box of coil nails typically lists length, shank diameter, head diameter, coating and collation, for example 1 1/4 inch by 0.120 inch with a 3/8 inch head, electro-galvanized, wire coil. Check that each number meets your shingle maker's spec and the code minimums before buying.
Why size matters on a Georgia roof
Most shingle blow-offs after thunderstorms trace back to fastening: nails too short, heads too small, or nails in the wrong place. Using the standard size, in the right spot and quantity, is what lets shingles reach their rated wind performance.
See roof anatomy explained and wind damage to roofs in Georgia.