Ponding is a common problem on flat commercial roofs. Ponding should be addressed as soon as possible because it can lead to roof failure and building leaks. Your maintenance crew should check for ponding regularly so you can call a commercial roofer if the problem arises. Here's why ponding is such a problem, why it develops, and what a roofer might do to fix the situation.
Why Ponding Is A Serious Issue
While flat roofing is made to be as waterproof as possible, if water sits on the roof without evaporating, the roofing material may start to degrade. If ponding occurs over a seam, the adhesive may start to degrade and lead to a roof leak. Even if the water doesn't cause roof damage, the water will attract bugs and birds to your roof. Plants can even start to grow in the water and their roots might cause roof damage.
Even worse, if your roof has drainage problems, the ponding water might void your roof warranty. For these reasons, finding a fix for the roof drainage problem is important. The approach your roofer takes depends on the type of roofing your building has, the number of drains, and the reason for the improper drainage.
Why Roof Ponding Happens
Puddles form on a flat roof when there is a drainage problem. A flat roof has a slight slope so rain drains toward gutters. If the gutters or roof drains clog up with leaves, twigs, or bird nests, then the rain won't be able to drain. In that case, the ponding usually occurs around the drains. If ponding occurs in the middle of the roof away from drains, the problem might be due to improper roof installation or settling of the building that changes the slight slope of the roof.
How A Commercial Roofer Can Help
Your roofer might be able to make repairs to the ponding areas. One approach is to clear out clogged drains so water can flow off the roof freely. The roofer might even try putting in additional drains to increase drainage capacity. The roofer may decide to build up the roof to restore the slope or install crickets to route the water toward a drain.
If damage has been done to your roof, or if your roof is old anyway, your roofer might suggest a new roof which can be installed with the proper slope. Commercial roofing membranes or spray foam roofing can be installed with slope creation in mind so rain rolls toward the gutters as intended and the ponding on your roof is eliminated.