Why valleys fail
- Missing ice & water membrane under the valley
- Nails in the water path
- Debris dams that hold melt water
- Cut shingles without proper metal or woven detail
Open vs woven
Open metal valleys shed water fast and are easy to inspect. Woven asphalt valleys can work when installed carefully — both need membrane underneath in NH.
We specify the valley method in writing so quotes are comparable.
Repair vs reroof
Isolated valley damage on a sound roof may be repairable. Widespread valley leaks on an aging field usually mean full replacement.
Document stains and photos before temporary patches hide the source.