We got called to a home in Coquitlam with water leaking into the garage. The drywall was soaked and damaged, and we had to cut it open to get at the source. The cause turned out to be a single slid roof tile, and the reason it was so hard to track down is worth explaining.
It started with one slid tile
A single tile had slipped out of place and left a small gap. That does not sound like much, but all the water running down that section of roof funnels into the gap and gets under the tiles.
Why a small gap turns into a big leak
Once we pulled some tiles, we could see what was happening. Under a tile roof there is usually no plywood, just underlay over the battens and trusses. Near the eave, where the gutter and its plywood start, the underlay can sag into a little channel. Instead of draining out into the gutter, water collects in that channel and sits there until it seeps through.
Lifting the underlay showed the wet truss and exactly where the plywood ends. That edge is where the pocket forms.
Why the leak was so hard to find
This is the part that makes these leaks tricky. The leak was showing up at one end, but that channel runs all the way along the eave. Water gets into the channel at the slid tile and then travels along it, so it can come through the ceiling far from where the actual problem is. If you only look directly above the stain inside, you will never find it.
What we did
We found the slid tile, corrected the underlay so water drains into the gutter the way it should instead of pooling, and re-set the tiles. Inside, the damaged drywall in the garage had to be cut out and repaired.
Seeing a stain on a tile roof? Do not ignore a slid tile
If you have a concrete tile roof, watch for tiles that have slipped out of line. One slid tile can let water travel along the underlay and cause damage well away from the tile itself, and by the time it shows up inside it has usually been getting in for a while. Catching it early is the difference between resetting a tile and cutting open drywall.
We repair concrete tile roofs across Greater Vancouver and serve Coquitlam and the Tri-Cities. Call 778-389-5564 for a free estimate.