How to prevent ice ponding on your building roof in St. Louis

The winter winds are howling through the Lou and we’re shivering our way through the holidays. The winter is also a high-risk time for developing ponding on your warehouse or office building roof. Water tends to collect on flatter roofs, especially when temperature is close to freezing, an effect we know as ‘ponding’.
Ponding water does not have the natural slope to run off into gutters and downspouts. It can accelerate the deterioration of your roofing material in any season. The added risk is when ponding water begins to freeze on commercial roofing systems.
Now, you may not know that ice actually weighs less than water:
- A cubic foot of water weighs approximately 62.4 lb.
- A cubic foot of ice weighs approximately 57.2 lb., over five pounds less than a cubic foot of water!
Water expands as it freezes into ice, which is why a gallon of water takes up less space than a gallon of ice. In fact, it’s because water expands into ice that pipes burst during the winter. The freezing water has nowhere to expand and the pressure eventually ruptures the piping.
Imagine your 30,000 square foot roof holding several gallons, maybe even over a hundred gallons of water. As we learned earlier, ice weighs less than water, but it also takes up more space. If you have ponding water trapped inside a more confined space, such as between exhaust pipes on your roof, the freezing water has less room to expand into ice. This places added pressure on any of your roofing structure in contact with the water. The end result may be a rupture in your roofing surface that you may not realize until the ice melts and water invades the new opening.
Of course, we don’t share these details with you to make you overly cautious about any water being on your roof. Water is supposed to be on your roof because it’s better than water being in your building.:) The important distinction is whether the water is sticking around, or ‘ponding,’ on your roof surface.
Our R&A Contracting team is trained and experienced in correcting ponding issues for commercial roofing. We provide complimentary on-site inspections to evaluate the cause of ponding on your roof. The solution is often non-invasive and affordable. We help you make minor calculated changes to your roof to avoid major repairs or even replacements in the future.