Flat roofs have a very slight inclination, invisible to the eye, that’s why heavy rains can form ponds on their surface. This is not a reason of concern unless water remains on the roof for more than 48 hours.
The flat roofs are designed to resist water ponding, being covered with sealing membranes and provided with water drainage systems. However, ponding water is always a risk and must be avoided to protect the roof. Flat roof commercial roofers in Denver are experts in this area, and can be called upon for inspections, repairs, and all other roofing services.
First, standing water adds weight on the roof and increases the pressure on its structure. It weighs about 5 lbs. per inch, so a large ponding area can stress the roof more than you may realize. Also, as water accumulates, it tends to cause deck deflections (sags), which will gradually increase the ponding water problem, compromising the structural integrity of the decking.
Ponding water also cause premature wear because it attracts algae formation and dirt, so the roof`s membrane is more prone to rot.
The building owner must address this problem promptly, not just because of the risks, but also because most roof warranties are voided if the water ponds for more than 48 hours. A flat roof must be carefully inspected after each rain storm.