A homeowner in Port Moody called us about a leaking skylight on their concrete tile roof. The skylight itself turned out to be fine. The real problem was hidden in the pan flashing right beside it. Here is what we found and how we fixed it.
The problem: a skylight that kept leaking
When water shows up around a skylight, the glass and seals usually get the blame. On this Port Moody tile roof, though, the leak was coming from the pan flashing, the metal channel that runs alongside the skylight and carries water down the roof.
What we found: debris damming the pan flashing
We removed a few tiles next to the skylight to see the pan flashing underneath, and the channel was packed with debris.
Here is the part most homeowners do not realize. That debris acts like a dam. Water running down the roof hits the buildup, backs up, and jumps over the containment lip on the pan flashing, the lip that is meant to keep water out. Once it is over the lip, it runs under the tiles and into the roof.
This roof had trees nearby and moss on the tiles, which is exactly the recipe for it. Organic debris washes down the slope and settles in the flashing, year after year.
The repair: clear, strain, and re-seal
Once you know what you are looking at, the fix is straightforward:
- Lift the tiles around the skylight.
- Clear the channel and strain out the containment lip so water drains the way it should.
- Re-seal the corners of the pan flashing with caulking, since the corners are the most common spot for water to sneak through.
- Reset the tiles, leaving the skylight watertight again.
How to keep it from happening to you
Pan flashing leaks are almost always a maintenance issue, not a defect. If you have a skylight, chimney, or wall meeting a tile roof, the pan flashing beside it needs to stay clear:
- Have your pan flashings cleaned regularly, especially with trees overhanging the roof or moss on the tiles.
- Do not wait for a ceiling stain. By the time you see it inside, water has been getting in for a while.
- Pair flashing cleaning with a moss treatment if your roof is shaded or damp.
Skylight or roof leak in Port Moody?
If you are seeing water around a skylight, chimney, or roof wall, we can help. We repair concrete tile roofs across Greater Vancouver and serve Port Moody and the surrounding Tri-Cities. Call 778-389-5564 for a free estimate.