We inspect a lot of torch-on (SBS) flat roofs, and the same handful of problems come up again and again. Here are the ones we found on a commercial roof in Aldergrove, and why each one leads to leaks if it is left alone.
Flashing coming apart, patched with mastic
The flashing was bad and coming apart in places. On top of that, it had been sealed with black roof mastic. Mastic is a temporary patch. It dries out, cracks, and fails, and it is usually a sign that someone band-aided a problem instead of fixing it properly.
B-vent storm collars not caulked
The storm collar at the top of the B-vent needs caulking. Without it, water runs straight down the pipe and gets into the roof.
Drain strainers getting plugged
The drain strainers were getting plugged with debris. A plugged drain means water ponds on the roof, and standing water is hard on a torch-on membrane. It sits there and finds every weak spot.
Metal coping not fastened to the wall
The metal coping along the parapet was not fastened to the wall. Loose coping lets wind drive water behind it and into the wall and the roof below.
Why this matters
None of these are dramatic on their own, but together they are exactly how a flat roof starts to leak. Caught early on an inspection, they are cheap maintenance. Left alone, they turn into interior damage and, eventually, a full membrane replacement.
If you own or manage a flat or torch-on roof, get it inspected before the rainy season. We repair and maintain torch-on SBS roofs across Greater Vancouver and serve Aldergrove and the surrounding area. Call 778-389-5564 for a free estimate.