We got called to a home in Vancouver with leaking roof vents on a concrete tile roof. The tiles were the S-shaped, wavy profile, and that shape is exactly why the original plastic vents were leaking.
Why plastic vents leak on S-shaped tiles
On a wavy S-tile, a plastic vent does not sit flat. To make it fit, the flange has to be bent downward to follow the curve of the tile. The way these usually go in, the vent is set down, roof mastic is smeared on the flange, and the tiles are laid over top.
The problem is the mastic. With our hot summers and cold winters, the sealant dries out and cracks. And because the flange is already angled downward, the moment any water gets past the mastic it is pointed straight under the tiles and into the roof.
The fix: lead-based gooseneck vents
Instead of fighting the tile shape with plastic and mastic, we replace these with metal gooseneck vents that have a lead flange. Lead is soft, so we can glue it down and dress it so it conforms to the exact shape of the S-tile. It molds to the tile profile and seals without relying on mastic, so water cannot get under it.
S-tile vs flat tile
One detail worth knowing: we only need the lead-based vents on the S-shaped, wavy tiles. On flat tiles, a normal gooseneck vent sits fine. The lead version is specifically for the wavy profile, where a flat flange will never seal properly.
Leaking vents on a tile roof?
If you have a tile roof and a leak near a vent, the vent flashing is the first place to look, especially on S-shaped tiles where plastic vents and mastic just do not hold up. We replaced the leaking vents on this Vancouver home with proper lead gooseneck vents and stopped the leaks for good. You can also read more about replacing brittle plastic roof vents.
We repair concrete tile roofs across Greater Vancouver and serve Vancouver and the surrounding area. Call 778-389-5564 for a free estimate.