Water On Roof, Or Roof Ponding In Phx

City officials across the nation are advising business owners to inspect their flat roofs following rain to see if they might be at risk of a roof collapse because of poor drainage issues. Every year in the United States commercial buildings are extensively damaged or destroyed by the affects of rooftop ponding water. One large ponding area on a commercial roof can easily weigh more than an F-250 pickup.

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 (commercial roofs and residential roofs alike). 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.

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. Commercial buildings with massive square footage are at increased risk.

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! Protect your Phx roofing system now.

Ponding Water Can Become a Serious Health Issue On Phoenix Area Commercial Roofs:

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 Phoenix area roof inspected frequently, especially after a good rain to avoid future problems or at worst premature roof replacement.