What problems do flat roofs have in this climate?
Flat roofs do not shed water by gravity as well as sloped roofs, so drainage matters. Heavy summer rain can sit on a roof that has low spots, clogged drains or blocked scuppers, and standing water speeds up wear on the membrane.
The other common problems include:
- Seams that open as the membrane flexes in the heat.
- Punctures from foot traffic and equipment service visits.
- Failed flashing at parapet walls and air conditioning curbs.
- Blisters and cracks in older built-up and modified roofs.
- Wind lifting edges and corners, especially in storms.
Many leaks on commercial roofs start around rooftop air conditioning units, drains and pipe penetrations, so those are the first places we look.

