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Roof Ponding. The Dangers Of Standing Water On A Flat Roof.

Ponding water on a roof is a calamity waiting to happen.

Whatever the cause of the standing water, the problem will worsen with time. Without a roof water diverter, the weight of the water will erode the roof system and possibly collapse the roof. The weight of water pooling on a flat roof will easily exceed the designed weight threshold of the roof.

Flat Roof Ponding Is Destructive.

What is Ponding Water: Ponding water is defined as the water which remains on a roof 48 hours or more.

Most flat roofs require some sort of pitch or slope to avoid ponding water. But unfortunately, ponding water occurs on most flat roofs. Ponding water can seriously increase the load on a roof assembly. As water accumulates, deck deflections (sags) can increase, resulting in more ponding water which could compromise the structural integrity of the deck.

Solar Powered Roof Pumps for Ponding Water

Ponding water creates hydrostatic pressure that forces water into even the tiniest pinhole imperfections. This is why most roof warranties are voided in areas that pond water for more than 48 hours. Additionally, ponding areas rot roofing membranes, attract dirt/mud and algae, and quickly destroy any reflectivity of reflective coatings.

By far the biggest risk associated with ponding water is weight and the potential for damage to the roof deck or collapse of the decking system.

Ponding water weighs approximately 5 lbs. per inch, per each square foot of roof surface. A ponding area 20'x20' at 1" deep would equal 400 total square feet at 5 lbs per foot or a roof live weight of 2,000 pounds!

That can be an additional ONE TON of live roof load of stress on your building's roof!

Drain Roof For Safety

Ponding Water Can Become a Serious Health Issue: If water stays on your roof several health issues can arise. Warming water facilitates the growth of algae, mixed with pigeon feces can create harmful fungal material that could effect the air quality in your building.

Have your roof inspected frequently, especially after a good rain to avoid future problems or worst premature roof replacement.

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