How to tell if worn chimney flashing is leaking
Worn or poorly sealed chimney flashing can hide leaks that eventually cause water to drip into lower levels during heavy rainfall. Because flashing often conceals vulnerable areas—like roof transitions or covered porch ceilings—it is difficult to spot active damage without checking for hidden moisture entry points.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
- 1cleaning, removing moss, and resealing stone and mortar
- 2Applying roofing tar or caulking around the base of the chimney
- 3Installing flashing along the base
- 4Cutting out bad pieces, replacing them, caulking, and painting
In their words
Unedited, most upvoted first, each linked to the thread it came from.
“Wanting to make this chimney look better. My gut tells me water is running behind the trim because they didn’t caulk.”source ↗
“Should I just replace trim? Or does this need to be a full gut and resheath?”source ↗
“Unsure what I’m getting myself into and wondering what someone who charge to fix.”source ↗
“However with heavy rainfall we are now getting rain water dripping into our basement along the chimney vent.”source ↗
“No flashing = leak. They just caulked the fuck out of it”source ↗
“was looking at this strip of flashing and it looks pretty worn.”source ↗
“am I missing any glaring red flags here?”source ↗
“I don’t any see signs of leaking but this goes down into covered porch ceiling so hard to tell. Any maintenance or touch ups I should be doing?”source ↗