What are ridge cap shingles, and how do you replace them?
Short answer. Ridge cap shingles are thicker, pre-bent or pre-cut shingles that fold over the peak of a roof and over hips to seal the joint where two slopes meet, often covering a ridge vent. Replacing damaged caps means breaking the seal on the overlapping pieces, removing the nails, sliding in matching caps, and nailing them where the next piece covers the fasteners.
Why caps fail before the rest of the roof
- Wind: the ridge is the highest, most exposed line on the house, so caps take the strongest gusts.
- Hail: caps sit on top of everything and take direct hits. Adjusters routinely check caps for bruises and cracks.
- Age: as asphalt stiffens, caps crack along the fold first.
- Installation: short nails or stretched exposure leave caps loosely held.
Replacing a damaged cap
- On a cool morning, gently break the seal of the cap above the damaged one with a flat bar.
- Remove the nails holding the damaged cap and the nails of the next cap that pass through it.
- Slide the new cap into place at the same exposure.
- Nail it with nails long enough to reach the deck through any ridge vent, then renail the cap above.
- Press the lifted caps back down, adding a small dab of sealant where they will not reseal on their own.
Ridge vent caps
On a ridge vent, the caps nail through the vent into the deck, so longer nails are needed, and the vent itself should be checked for crushing or cracks while the caps are off.
Cost and matching
Cap shingles cost more per foot than field shingles, and estimates list them as a separate line by linear foot. Matching color on an older roof is often difficult, and a mismatched ridge is very visible.
See ridge vent vs box vents and wind damage to roofs in Georgia.