Flashing is the membrane or metal that seals the roof where it meets a wall, parapet, chimney, vent, drain or skylight. These spots move and change direction, so they leak far more often than the membrane itself. A flashing redone by a roofer usually costs much less than a replacement and often stops the leak.
Where flashing is found
- Along parapets and walls
- Around brick chimneys
- Around plumbing vents and exhausts
- Around drains and strainers
- Around skylights and roof hatches
- Under HVAC equipment and supports
Why it leaks
- Movement from seasonal expansion and contraction
- Too-low upstands that let meltwater in
- Aging sealant and metal collars
- Sloppy work during a reroof or equipment install
What to require from the roofer
- Removal of the old flashing, not just sealant on top
- A membrane upstand of sufficient height
- Well-fastened, sealed counter-flashing
- Before-and-after photos and a written warranty
Read next
Service: roofing quotes · Version française
General information. Have your flashing inspected by an RBQ-licensed roofer.