Flat commercial roof with a large puddle of ponding water around rooftop HVAC units.

Whether you’re manufacturing or have a retail space where clients are visiting your business, an intact, functional roof is a must. Too many people take a proper drainage system on their low-slope or flat roof for granted and don’t consider the serious risk of standing water. After all, what harm can a simple puddle do?

Don’t Underestimate Roof Ponding on Your Flat Roof

A small amount of pooling water on your commercial roofing system might not seem like a big deal at first, but ponding can lead to major costly damage to your roofing materials. Educating yourself on those issues is the best way to avoid them. Check out this list of what can go wrong when water pools on a roof surface.

1. Breeding Mosquitoes and Other Insects 

Nobody wants swarms of blood-sucking pests hovering around their building. Allowing water to pool on low points of your roof surface invites mosquitoes and similar insects (that are both a nuisance and a danger, as they can carry pathogens that cause serious illness).

Ponding water also leads to roof leaks or moisture seeping through the roof membrane. This can attract other bugs, such as termites, cockroaches, and beetles that can cause damage to your roof and could even gnaw their way into other parts of your building.

Even more, bugs around your commercial building can result in health-code violations, disgusted clients, and expensive repairs. A roof system that drains correctly is a safeguard against these potential infestations.

2. Animals Coming for a Drink

Critters other than insects aren’t as keen on breeding in standing water, but they do come to get a drink. Raccoons and rodents like squirrels, mice, and rats are the most common mammals attracted by pools of water on commercial roofs.

Birds like geese, ducks, seagulls and pigeons may splash around in the water, as well, and could be tempted to nest on your building.

Rather than facing this nightmare scenario and calling pest control after it happens, make sure that any flat roofing is in good shape and drains well.

3. Physical Damage From Freezing Water

During cold winters, ponding water can be especially problematic when temperatures drop below freezing. Ice damage is a consequence of ponding water during cold winter months, and there are a couple of ways it can occur.

The first mistake commercial building owners make is not keeping up with maintenance throughout the fall (which can also affect the roof warranty). Pools of rainwater from storms can begin to form, and falling leaves can cover the roof and prevent roof drains from working properly. Either way, water left to sit on the roof through fall and into winter is prone to freezing.

Additionally, snow buildup that melts needs somewhere to run to, and an improper or compromised drainage system will lead to ponding. When temperatures drop again, the ponds re-freeze and can lead to issues requiring major repairs or even roof replacement.

Water freezing and melting on your roof over extended periods of time causes problems in the same way ice deteriorates pavement and potholes. Gaps and cracks open because water expands when it freezes. The problem gets worse when those widened gaps fill with water and freeze again.

Remember to get an inspection to make sure your roof is sound before winter arrives. If you have ponds of water on your roof from fall storms, contact a reliable commercial roofer who knows how to drain water from your roof to evaluate the structure for necessary roof repair to ensure the problem won’t get worse.

4. Unwanted Vegetation Growth

Rooftop gardens are lovely, but unintended vegetation is quite the opposite. Chances are, you don’t want a “garden” made of weeds, moss, and algae. Your clients don’t want that, either, and a dingy roof covered in vegetation could turn them away.

But, vegetation on the roof is more than unsightly. Roots can make their way into crevices and tear your roofing membrane apart. Vegetation (and the debris it creates) clogs gutters and drains designed to prevent ponding, complicating the issue. It can also attract insects and other animals, making more debris and causing more damage. 

When that happens, animal droppings serve as fertilizer and create a positive feedback loop. Unless the damage is somehow contained to a small area, starting over with a new roof is the only thing you can do at that point. Make sure water doesn’t pool on your roof to avoid the expense of roof replacement.

5. Roofing Membrane Discoloration and Staining

Considering disasters like the above scenarios, discoloration and stains are relatively minor concerns. However, there’s still reason to worry about a discolored or stained roof.

Roof discoloration and staining can harm your business’s reputation. If your commercial building is open to clients, that ugliness is liable to make you lose business.

If you think you’re in the clear because you have a metal or dark-colored roof, you’re mistaken. This is an issue for all kinds of roofs. You could end up with gray patches on a black roof and water stains from all-too-prevalent acid rain on metal—even more, when the rainwater ponds.

Without ensuring your roof has enough slope and drainage, there’s no way to avoid these problems. There are some coatings you can apply to help prevent damage like this, but you shouldn’t test them by letting water pool on the roof. It’s best to talk to a roofing professional about coatings and to make sure your commercial building‘s drainage is appropriate for its roof slope.

Commercial Roofing Services Dedicated to Protecting Your Assets

The effects of ponding water on your business’s roof should be enough to convince you it’s time to make sure your commercial roof design isn’t compromised. If you’ve had ponding water issues before, get your roof checked for damage.

Whether you need those services or other roof care and repair, we have your back. TEMA Roofing Services is an industry-leading, family-owned business, and your satisfaction is our first priority. Get in touch with us today to put all your commercial roofing needs in good hands.