How To Stop Water Ponding On A Commercial Flat Roof

stop water ponding on a flat roofOver time standing water on a flat roof, also known as ponding, will deteriorate your commercial roof, and eventually cause leaks, damage the roof deck, its underlying insulation, and eventually leak into rooms below.

If your building’s flat roof has a commercial coating, like a white elastomeric coating, water ponding left unchecked will reduce the coating’s service life by slowly degrading its material and adhesion properties.

You should periodically inspect your building’s roof for ponding water areas. Building owners or property management companies will typically want to inspect a roof after prolonged heavy rainstorms, or at the same time they complete maintenance inspections of water sources located on the roof, such as air conditioning units or water cooler tanks. Water overflow from pans or liners can be the source of a water ponding. In addition, a damaged, clogged or obstructed gutter drain line can cause water to backup and pond on the roof.

Upon your roof inspection, if you see water has accumulated in roof indentations and formed pond areas, and they have not dissipated or drained after 48 hours, then it’s recommended you call a commercial roof company to explore preventative options how to stop water ponding. Manually sweeping standing water off the roof’s surface is not a long term solution to cause it to evaporate faster or move properly to drains.

Pitching Issues

Generally speaking, if your commercial flat roof system lacks sufficient pitch or slope, water ponding will occur. It’s important to not overlook other reasons, including but not limited to your building frame or displacement of tapered insulation. While every circumstance is different, an insufficient roof pitch or slope is usually the source of water ponding.

Divert Water Flow

There are a variety of methods we can use to stop water ponding on a commercial flat roof without having to do a full roof replacement. Whichever solution you choose, the goal is the same: to divert water away from the indentations that are causing ponding in the first place.

  • We can install roof crickets (aka “saddles”).
  • We can add additional drains or widen your existing drains.
  • We can reduce the depth of the ponding area.

All these flat roofing solutions will not affect the integrity of your existing roof structure or void a warranty.


If your building in Ventura County, Los Angeles County or Santa Barbara County has a ponding water area that needs to be corrected, or for emergency commercial roof leak repairs, request an inspection and proposal from JH3 Company.

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