Guide To Roof Valley Leaks
Roof valleys are the lowest spots on certain roof designs. For this reason, they can be more prone to leaks compared to the higher flat planes of the roof.
Pooling Water
Roof valleys can be prone to pooling water. Sometimes the problem is with the design of the roof itself. If the pitch of the valley is insufficient for good water flow, stagnant water may collect. Too many sloped planes leading into a single valley can also cause pooling, as can a valley that doesn't have a sufficient opening at the bottom for drainage of the collected water.