Replacing leaking chimney flashing
Q. The chimney is leaking at the flashing and, as a result, the water comes through the roof. What advice do you have regarding the replacement of the flashing? I plan to do the work myself. Amos L. Wood Mercer Island, Wash.
A. When removing the old metal flashing, pay attention to how it was originally installed. Repeat that method and use the same, or better, material
The secret lies in the leading edge of the flashing being caulked or masticed into the masonry mortar joint slit as well as carefully tucking it under the roofing material. Thoroughly caulk the laps.
Flashing and counter flashing are likely required to make the perimeter of the chimney really waterproof, especially during a driving rain.
Since you intend to do the work yourself, amble over to a sheet-metal shop to buy the materials. Talk to the manager about the finer points of chimney-flashing methods.