The Importance of Drainage for Commercial Flat Roofs

If you have commercial flat roofs, you know that proper drainage is essential to keeping your roof in good condition. After all, a flat roof is only as strong as its weakest point—and that weak point is often the drainage system.

Commercial flat roofs are different from residential ones in a few key ways. First, they’re much larger, which means they’re subject to more wear and tear. Second of all, they’re often used for storage, which can put even more strain on the roof. And finally, commercial flat roofs are also more likely to have HVAC units, which means that there’s a greater risk of leaks if the drainage system isn’t up to par.

All of this is to say that proper drainage is essential for commercial flat roofs. In this blog post, we’ll take a closer look at some of the ways that poor drainage can impact your commercial flat roof—and what you can do to prevent problems down the line.

The Risks of Poor Drainage

The Importance of Drainage for Commercial Flat Roofs

A few key risks are associated with poor drainage on commercial flat roofs.

1. Risk of Leaks:

First and foremost, there’s the risk of leaks. If water is allowed to pool on your roof, it puts extra pressure on the seams and membrane—increasing the likelihood of leaks.

2. Pooled Water Can Lead To Mildew:

In addition, pooled water can also lead to the growth of mold and mildew, which can weaken the structure of your roof and cause serious health problems for anyone inside the building.

3. Deck Rot:

Another risk associated with poor drainage is deck rot. When water seeps into cracks in the roof decking, it can cause the wood to rot—which weakens the roof’s overall structure. Finally, poor drainage can also lead to ice dams—a serious problem here in Massachusetts. Ice dams occur when the snow melts and then re-freezes at the edge of your roof, forming a dam that prevents water from draining properly. This can cause even more leaks and damage to your roof.

What Can You Do?

Fortunately, there are a few things you can do to prevent poor drainage on your commercial flat roof.

1. Make Sure Gutters Are Clean:

First and foremost, you should make sure that your gutters are clean and free of debris. This will help ensure that water flows freely through them and doesn’t back up onto your roof.

2. Inspect Your Drains Regularly:

You should also inspect your drains regularly to make sure that they’re clear of leaves and other debris—and if you do notice any clogs forming, be sure to take care of them right away before they have a chance to cause any serious damage.


Proper drainage is essential for commercial flat roofs—but it’s not always easy to achieve. By taking some preventative measures and being vigilant about maintaining your gutters and drains, you can help ensure that your commercial flat roof stays in good condition for years to come.

Contact us today at if you need help with any aspect of commercial flat roof maintenance or repair!

Originally posted 2022-11-15 15:37:52.