What size nails are used for roofing?
Short answer. Roofing nails for asphalt shingles are sized by length, gauge and head: typically 1-1/4 to 2 inches long, 11 or 12 gauge, with a head at least 3/8 inch across. Code sets the minimum at a 12 gauge (0.105 inch) shank and 3/8 inch head, and length is chosen so the nail goes 3/4 inch into the deck or all the way through it.
The three numbers on the box
- Length. Measured from under the head to the tip: 1, 1-1/4, 1-1/2, 1-3/4 and 2 inches are standard. 1-1/4 inch is the workhorse for new shingle roofs.
- Gauge. The shank diameter, where a lower number means thicker: 11 gauge is about 0.120 inch and 12 gauge about 0.105 inch. Many coil roofing nails are around 0.120 inch.
- Head diameter. 3/8 inch minimum for shingles; some nails have 7/16 inch heads.
Other details that matter
- Coating. Galvanized for shingles; stainless or copper to match certain flashing metals.
- Shank. Smooth, barbed or ring shank. Ring shank grips better in wood.
- Format. Hand drive nails in boxes, or wire-welded coils for nail guns, usually 15 degree coils.
Why penny sizes do not apply
Framers size nails by pennyweight, such as 8d or 16d. Roofing nails are sold by actual length, so a 1-1/4 inch roofing nail is what you ask for at the supply house.
Which size for which job
Field shingles over 7/16 or 1/2 inch decking: 1-1/4 inch. Thicker shingles: 1-1/2 inch. Ridge caps and ridge vents: 1-3/4 to 2 inch, or whatever the vent maker specifies. Metal panels use screws with sealing washers rather than roofing nails. See roof anatomy explained and ridge vents vs box vents.