Ridge cap guides
Updated October 11, 2026.
Nine short pages for the questions that show up next to a cap order. The numbers match the estimator.
On the roof
How to measure a ridge and the hips
Tape the peak, then each hip on the slope.
The order
How many ridge cap bundles you need
A 40 by 30 hip and a 50 foot gable, worked out.
Air and water
Ridge vent versus hip caps
Vent the ridge. Cap the hips. Order vent in 20 ft rolls.
The wrapper
20, 25, or 31 feet per bundle
The default is 25. The bag can say something else.
Fasteners
Where the cap nails go
In the overlap, about every 6 inches. Not through the face.
Slope
Pitch in degrees and in rise
6:12 is about 27°. Steeper hips get longer.
Metal
Ridge pieces of 10 feet
Waste first, then round up to a whole piece.
The ends
Hip starters and end caps
Two on a gable. Four starters on a hip.
Cuts
Why a hip wastes more
10% on a gable. 15% on a hip. 12% on an L.