What is the difference between a ridge cap and a ridge roll?
Ridge cap
The finishing layer along the peak. On shingle roofs, it is a row of hip and ridge shingles folded over the ridge. On metal roofs, it is a bent metal piece fastened over closures. It is the weather seal at the top of the roof.
Ridge roll, meaning one: rounded metal cover
Older homes, slate roofs and some historic styles use a rounded metal roll, often aluminum or copper, nailed along the ridge instead of cap shingles. It is durable and distinctive, but on an asphalt roof it can look out of place and must be detailed carefully to stop wind driven rain at its edges.
Ridge roll, meaning two: rolled ridge vent
Many shingle over ridge vents come in long rolls of filter type or corrugated material. Roofers roll it out over the vent slot, nail it down, and then cover it with ridge cap shingles. In that sense, the ridge roll is the vent and the ridge cap is the weather layer on top. See ridge vents vs box vents.
Which do you need?
- A vented shingle roof: rolled or rigid ridge vent plus matching ridge cap shingles.
- An unvented ridge: ridge cap shingles alone, with exhaust handled elsewhere.
- Historic or slate roofs: a metal ridge roll may be the authentic choice.
On any vented ridge, intake at the soffits must match the exhaust. Roof ventilation basics explains the balance.