Step flashing on roofs is intended to prevent the intrusion of water between a wall and shingles where the step flashing on the side of the shingle meets a vertical wall termination. To repair these flashings there are certain facts you should be aware of to prevent unwanted water leakage.
Preventing Shingle Buckling
Water is less likely to flow freely down your roof and is more likely to leak if a shingle is buckled and creating space between the shingle end and the wall. To prevent this, bend the flashing 90 degrees. This will redirect the water over the surface of the shingle and most likely correct the problem.
Finding the Cause of a Leaky Step Flashing
To find the probable cause of leaky step flashing, inspect the flashing for gaps that allow water and moisture intrusion. This leaking can be caused by failure to securely fasten the step flashing or from installing it improperly.
Finding Leaks at a Wall
Water leaking at a step flashing is sometimes caused by a poorly installed channel on a stucco wall. To repair this you can cut the lip from the channel and install new step flashing and counter flashing.