Typical Causes of Roofing Leaks Cont d.5. Valleys or low slopeOne problem that periodically takes place in domestic roofing is a valley between two peaks of a roofing system. Water has the tendency to run here and become trapped, and trapped water is more most likely to leak. Low slopes are at high risk for a comparable factor: water doesnt stream off them as quickly as it does from a steeper slope.We also provide expert roofing services in: roofing consulting