What size roofing nails do you use for ridge cap?
Why ridge caps need longer nails
At the ridge, a nail goes through the thick cap shingle (many caps are double layer), the top courses of field shingles, the underlayment, and on vented roofs the ridge vent itself, which can be an inch or more tall. A 1-1/4 inch field nail cannot reach the deck through all of that, and short nails at the ridge are a common reason caps blow off in Georgia thunderstorms.
Placement
- Two nails per cap piece, one on each side, about an inch in from the edge and inside the area the next cap covers.
- Through the vent's marked nail line, so the nail holds the vent evenly without crushing it.
- Ridges capped starting from the end opposite the prevailing wind, so the laps face away from wind-driven rain.
- Hips capped from the bottom up.
Cut 3-tab vs manufactured caps
Older roofs often used 3-tab shingles cut into thirds for caps. Most architectural systems today use the maker's hip and ridge shingles, which are thicker and may need even longer nails. Using the matching caps also keeps system warranties intact.
Cold weather tip
Cap shingles bent over a ridge can crack in the cold, so crews warm them or follow the maker's cold weather guidance during a Georgia winter.
See ridge vents vs box vents and wind damage to roofs in Georgia.