As a commercial property owner or manager, you understand the importance of maintaining a leak-free roof. Unfortunately, flat roofs, though not entirely flat, can pose challenges regarding water drainage, making them more prone to leaks if not properly maintained. With 50+ years of industry experience, we have accumulated the top 5 reasons why your flat roof is leaking, from blisters in your roof membrane, damaged flashing, installation problems to water pooling and lack of maintenance.

1. Blisters in the Roof Membrane

One common cause of flat roof leaks is the formation of blisters in the roof membrane. These blisters occur when small air pockets develop and become trapped under the membrane or between its layers. When heated by the sun, these blisters expand, stretching the membrane and potentially leading to cracking and leaks.


Blisters typically result from moisture and air becoming trapped during installation or from ongoing exposure to moisture and temperature fluctuations.


To address blisters, it’s essential to inspect the roof regularly and quickly repair your flat roof to address any air pockets that develop under the membrane. This involves cutting out the blistered material and replacing it with a new membrane, extending at least five inches above the blister’s edge.

blisters in roof membrane leads to cracks in membrane

2. Loose Collars or Damaged Flashing

Structural components routed through the roof membrane, such as drains, HVAC units, or vent pipes, can be vulnerable points for leaks if collars or flashing are loose or damaged. Properly sealed flashing directs water away from these areas and towards proper drainage systems.


Improper installation, such as inadequate sealing or fastening is one major causing flashing failure and subsequent leaks. Over time, flashing can degrade due to exposure to UV rays, expansion and contraction caused by temperature fluctuations, or corrosion from exposure to moisture and debris.


Regular inspections are crucial for identifying and addressing loose collars or damaged flashing promptly. Ensuring proper installation by experienced commercial roofers, such as Industrial Roofing, and using compatible roofing products can help prevent future leaks.

damaged flashing can allow water into roof membrane

3. Installation Problems

Improper installation of roofing materials can lead to various issues, including leaks. Whether it’s EPDM roofing installation, TPO roofing replacement, or any other type of flat roofing system, precise installation procedures are crucial for long-term performance and durability. Different roofing materials require specific installation techniques, and any errors during installation can compromise the roof’s integrity, leaving it vulnerable to leaks and other problems.


Inexperienced installers may overlook critical steps or fail to follow manufacturer guidelines, leading to subpar workmanship and increased susceptibility to leaks. Additionally, using materials that are not designed for the specific roofing system or incompatible with other components can result in premature failure and water infiltration.


Hiring skilled professionals for flat roof installation and repair is essential to avoid installation-related issues. Proper training, adherence to manufacturer guidelines, and quality control measures can help ensure a successful installation that minimizes the risk of leaks.

professional flat roof replacement prevent leaks

4. Poor Drainage and Water Pooling

Flat roofs are not efficient at draining water compared to sloped roofs, making them susceptible to water pooling. If water remains on the roof for extended periods, it can seep into the membrane, causing damage and eventual leaks.


Poor drainage and water pooling can result from an inadequate slope, clogged drains or gutters, or structural issues.


Regular flat roof maintenance, including cleaning gutters and drains and ensuring proper slope, is crucial for preventing water pooling. Installing tapered insulation and maintaining drainage systems can help improve water flow and minimize the risk of leaks.

water pooling on flat roof

5. Lack of Maintenance

Neglecting regular maintenance is a common reason why flat roofs develop leaks over time. Without proper inspection and upkeep, minor issues can escalate into significant problems, compromising the roof’s performance and longevity.


Ignoring flat roof maintenance can lead to the degradation of critical components in a flat roof, which causes the roof to become vulnerable to water intrusion. Over time, exposure to environmental elements and wear can compromise the integrity of these seals, allowing moisture to penetrate the roof membrane.


To prevent the deterioration of flat roof components, it’s essential to conduct bi-annual or annual maintenance, including regular inspections to identify signs of wear and damage. Adhering to the maintenance requirements outlined by major roof manufacturers is crucial for preserving the warranty coverage of the roof system.

annual maintenance is essential to preserve flat roof

Emergency Roof Repair Service

Unexpected roof leaks can cause significant damage to your property if not addressed quickly. That’s why Industrial Roofing offers emergency flat roof repair services with a 2-hour response time. Our repair crews are dispatched immediately to stop the leak and implement permanent repairs whenever possible. If temporary measures are needed, we’ll ensure to cease water infiltration and provide recommendations for permanent repair solutions.

Don’t let a leaking flat roof compromise your property’s integrity. Contact Industrial Roofing for reliable flat roof repair services and proactive maintenance to keep your roof leak-free and your business protected.

Whether you need a flat roof inspection, repair, or replacement, our team of experienced professionals is here to assist you!

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