Issues caused by 'ponding water' on commercial flat roofs

The long-range forecast for Southern British Columbia including Vancouver predicts above-normal precipitation this winter. So far we’re on track with 209.9mm of rain falling in December, which is over 40% higher than the average of 148.3mm. 

All that precipitation is bad news for a flat roof. If it’s not draining properly water will begin to pond. Ponding water is water that hasn't dissipated after 48 hours. It causes all sorts of problems and is a good reason for calling a commercial flat roof contractor in Vancouver.

Commercial flat roofs are not designed to take sustained extra weight of water remaining on the roof and may start to sag. Water also magnifies the sun’s UV rays, causing premature aging of the roof’s surface. And, over time, all that extra moisture encourages the growth of algae and moss which can damage roofing membranes. Ponding water that freezes can expand and cause further damage.

There are a number of reasons why water will pond. There could be structural issues. The roof may have been poorly designed right from the start. Dents or damage to the surface can cause puddles to form. Debris can block drains. HVACs or other rooftop equipment can block the flow of water. Whatever the reason the only way to know for sure is to have a professional commercial flat roof maintenance contractor inspect the area.

Ponding water doesn’t require immediate attention but it will cause problems in the long-term and will shorten the lifespan of your roof. A commercial flat roof contractor will be able to determine the issues specific to your roof and make the repairs to fix them.