Ponding water on a flat roof
Ponding is the phenomenon of water pooling on flat roofs after storms, snow melts, or heavy rains. Pools should drain away without causing any damage to the structure – but building owners should know when to take action, how to identify the cause of the ponding, and how to resolve it.
A few reasons why the water may not be draining are:
- The drains or gutters are blocked with debris
- The pitching of the roof was not done correctly (weak membranes, caulking issues, etc)
- There is too much roofing material on the edge of the roof
- The flashing was not installed correctly