What are the causes of commercial roof leaks?

What are the causes of commercial roof leaks?

All roofing has weaknesses, whether it is residential or commercial in makeup. The moment moisture seeps beneath the protective barrier, it is game over.

Even if there are no signs of leaking right now, your commercial roof could be starting to fail. Although no one wants to see a commercial roof leak, you cannot overlook the possible damages either.

One way to arm yourself is to know the answer to the question “What are the causes of commercial roof leaks?” If you don’t know, then keep reading to learn more.

Signs of Commercial Roof Leaks

Before getting into the causes of leaks, knowing the signs of a leak is important. This will help you identify that something is wrong before the problem spreads and becomes catastrophic.

The signs include:

  • Mold and Odor: A strange odor that cannot be covered up with scented air fresheners points to mold growth in the walls or ceiling. Mold grows where there is moisture and rot.
  • Dripping Water: The most obvious sign that your commercial roof has a leak is the sight of water rivulets and droplets overhead or puddles on the floor. This also means the leak is rather large, so do not wait to get it repaired.
  • Staining: When you see discolored walls and ceilings in your building, the reason is apparent: You have a roof leak. Since this can mean extensive water damage, you need to find the root of the cause as soon as possible.

Common Causes of a Commercial Roof Leak

Now that you know what to look for, here are some reasons your walls are stained yellow or brown and there is an odor in the air:

Penetrations, Punctures and Other Damages

There are some penetrations that you cannot avoid, like vents, HVAC units, drainage and pipes on the roof. These pieces need to penetrate the roofing system to function properly, but in doing so, they create another chink in the armor, so to speak. These places need to be given special attention during installation to ensure that there will be no gaps or unfinished seals.

Secondly, even if the membrane is installed perfectly, commercial roofing is more susceptible to damage than steeper roofs because of foot traffic, dropped equipment, and debris. You need to make sure that the surface of the roof is being maintained and repaired whenever it is ripped or broken. If you don’t find the punctures quickly, the insulation beneath the membrane could get damaged. That leads to extensive and expensive repairs.

Aged Materials

A roof is not meant to last forever, especially commercial roofing. Keep in mind that flat roofs often have a lifespan of up to 20 years, even with routine maintenance. If you have roof with a decent pitch and are not using flat roof materials, then the lifespan may be around 30 years. That said, constant exposure to sunlight and heat, as well as storm-related damage, can prematurely age your roof.

Dismal Drainage

Ideally, a roof should be able to tackle water with things like scuppers, gutters, and internal drainage pipes (or a combination of all three) to keep it from getting too waterlogged. However, it’s also possible that your commercial roof drainage has an issue that prevents it from working adequately. When that happens, water will begin to collect on the roof or cause leaks elsewhere in the building. If you notice that water is not draining properly from the roof, be sure to inspect the drainage for damage or blockages.

Routine inspections are the best way to prevent such things from happening, so be sure to schedule an appointment with a trusted commercial roofer.

Failed Flashings

A flashing is a section of metal specially designed to fit in corners or around objects set within the roof, like chimneys and skylights, to help make these areas more watertight. Other common places include roof edges and dormers. When flashing is not installed properly or is damaged or aged, it will start to lift off the roof, providing space for moisture to seep in.

Improper Seals

You want your commercial roof to be as waterproof as possible. The biggest component of its ability to resist water is the seals. If seals are not applied or if the roof is not installed correctly, the membrane may have gaps and air bubbles where moisture can collect. In other words, if seals are not done correctly, your waterproof roof is going to be more like Swiss cheese.


Hopefully, you now know the answer to the question at the beginning of this article. Commercial roof leaks are commonly caused by failed seals and flashing, damages to the membrane, penetrations, pooling water, and poor drainage. Be sure to do routine maintenance to keep these problems from occurring and to extend the lifespan of your commercial roof.

Is your commercial roof leaking? Don’t panic! We can help. Get in touch with us by calling or filling out the contact form to set up an appointment to get your commercial roof inspected or repaired or if you have any other questions.

Reference: https://rgbconstructionservices.com/what-are-the-causes-of-commercial-roof-leaks/