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What Should You Do If Your Commercial Roof Leaks?
WSI Comandix • March 5, 2021

One of the common problems a commercial building with a large roof surface may face is a leak. Even with a high-quality roofing system, general wear and tear and severe weather can damage a flat roof, increasing the chances of leakage. As a local roofing company, we understand that flat roof leaks can be hard to identify and repair. The best way to manage them is to understand the causes of leaks on flat roof surfaces, so you know what to do if you come across one. If you are prepared to control the leak, you can avoid further damage to your facility and ensure its longevity.


Being a top-rated roofing contractor in Toronto, we have the skills to manage leaks. Our experts have put together this guide to help you become aware of the essentials of commercial roof leaks.

Reasons for Commercial Roof Leaks

Membrane Seams

Over time, membrane roof seams can fail. Even small seam failures can lead to a major roof leak. This is why it is best to hire experts for periodic checks to examine the sheets of material that are seamed together.

Ponding Water Areas

Most commercial owners do not realize that ponding water on roofs leads to roofing problems. However, standing water will eventually damage the roofing system by causing a leak. This is why it is essential to examine ponding areas and ensure the water runs off as quickly as possible.

Damaged Flashing

A commercial flat roof has pieces of metal called flashing around vents and other accessories. Flashing helps seal the objects that protrude through the roof. It may corrode or puncture over time, resulting in a leak.

Discoloured Areas

Using low-quality roofing materials, continuous exposure to sunlight and wear tear are the reasons for large, discoloured areas on roofing systems. They are often the weak spots where leaks can form. Roof discolouration is also a sign that the roof is getting old, and you may need a new commercial roof coating.

Poor or No Drainage

Commercial roofing contractors know that drainage is an essential aspect when installing a roofing system. It is best to clean gutters, downspouts, drains, and scuppers regularly and ensure they are not clogged. Otherwise, you may have standing water on your roof that increases the chances of a leak.

Open Penetrations

Roof penetrations such as vents, HVAC units, pipes, drains, gas lines and more come through the roof membrane. These vulnerable spots are more prone to leaks. Sealing them properly during the installation phase can help enhance the structural integrity of your roof.

Aged Roof

Most commercial roofing systems typically last around 15 to 20 years, depending on the type of roof. Having a comprehensive maintenance plan can extend its lifespan. However, old roofs are prone to leaks, which is why you may have to replace them over time.

3 Common Signs of Commercial Roof Leaks

Stained Ceiling or Walls

Whether you have ceiling tiles on your roof or any other type of ceiling system, constant exposure to water tends to discolour your ceiling and walls. This is an easily recognized sign of leakage.

Odour or Mould Growth

An unpleasant smell in your facility could be a sign of mildew or mould growth, indicating a leak. Mould thrives in moist environments, where it can grow and spread.

Dripping Water and Puddles Inside

A sure sign of a commercial roof leak is when you can see water entering the building. It can be a drip above your head or a puddle on the floor.

Problems Caused by Leaks on Commercial Roofing System

Interior Damage

A leaking roof can damage not only the roofing system but also the interior structure of your building. If you fail to spot the initial signs, your ceiling tiles may start to stain, and it may be too late to preserve the structural integrity. It is beneficial to have a professional roofing contractor conduct regular inspections to avoid damage due to roof leaks.

Increased Utility Costs

When a commercial roof begins to leak, water may enter the building and damage your insulation. This will let the air inside your building escape easily and allow air from outside to enter. This will force your cooling and heating systems to overcompensate and increase your utility bill over time. If you suspect a leak, it is best to contact a top-rated roofing contractor near you for reliable solutions.

Premature Roof Aging

If you notice structural issues on your newer commercial roof, you may have severe water damage. It is best to seek professional roofing services for immediate assistance. They will assess the condition of your roofing system and help determine whether you need flat roof repairs or a complete roof replacement.

Health Problems

Leaking water leads to the growth of mildew and mould. It can damage your interiors and cause health issues to the staff inside the facility. This includes allergic reactions and breathing troubles. Regular maintenance and repairs by a roofing professional are the best way to keep your roof and staff healthy.

What to Do If Your Commercial Roof Leaks?

Here are a few things to keep in mind if your commercial roofing system leaks:

  • If you find water dripping or flowing into your facility, clear the area of people, inventory, tools and equipment, and supplies to reduce damage to the interiors.
  • Be sure to mark the location of the leak to discuss it with your roofing contractor and insurance agents.
  • Look for any problem areas in your facility to check if there is more water damage.
  • Reach out to a reliable local roofing company to have them assess your roof and fix it.

Choose Us for All Your Commercial Roofing Problems

At Global One Roofing, we are committed to protecting your investment with timely roofing services. As a top roofing contractor in Toronto and the GTA, we offer comprehensive services, including repairs, maintenance programs, roof replacement, and more.

Commercial Roofing Problems

If you are looking for a local roofing company near you to assist you with a roof leak or any other roofing problems, call us at 647-704-3084. We provide our services in North York, Mississauga, and Burlington. You may fill out our online form to request a free estimate. You can also check out our ratings and customer reviews on our HomeStars page.

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