If your roof looks like it has ponds across the surface of it after heavy rain, this is a sign of an issue with drainage. Another giveaway of ponding is the appearance circles of algae or dirt on the surface of the flat roof, indicating that ponding is occurring. Ponding can also indicate that the structure of the roof deck itself is affected, as sagging of the roof structure creates an uneven surface that allows water to pool. It may also be happening because of poor flat roof design, as the roof deck should be designed to have an accurate slope to enable water to drain away effectively. Whatever the cause, ponding issues should be addressed quickly after discovery, as ignoring such problems can lead to water ingress and subsequent leaking, which can cause expensive damage to both the remaining flat roof and the interior of the building.
