The Importance Of Drainage For Commercial Flat Roofs


Any type of commercial flat roof runs the risk of leaks. That’s why drainage for your flat roof is vital for the health of your roof and the entire building. If you are having drainage problems, this can be very problematic.

Even if you don’t see any signs of leaks or moisture damage doesn’t mean there aren’t any. A roof inspection from your professional roofing contractor can spot problems and potential problems.

Drainage Issues

Pooling water will always be a problem and can be a challenge to control. If standing water is left unchecked, there are multiple problems that can occur.

Mold and Mildew

One of the first issues to arise from pooling water on your flat roof is the growth of mold and mildew. It doesn’t take very long for mold to start growing and spread through your roof and into the building.

It can cause a bad musty odor, complicate respiratory issues, it looks terrible, and it can damage insulation, wood, and the roof system. If left too long, you may need to replace your roof.

Extra Weight

Water is heavy and if left to pool on your flat roof, it can start to cause a lot more damage than just moisture issues. These pools of water can cause sections of your roof to break and cave in.

Once this happens, the water is released inside and underneath the roof. This will cause damage to roofing materials and seep into walls. This leads to water damage, damp spots and can even mess with your electrical system.

The repair costs will be much more if your roof has rot and starts to erode from underneath. The damage can become rather extensive quite quickly and before you know it, your roof is starting to collapse.


Animals and insects will be drawn to the pools of water. Birds, mice and other rodents, and insects all gather at pooling water. Bird droppings come with their own health issues, mosquitoes lay eggs in sitting water, and bugs can get inside the building.

Birds can also start to nest around the water, leaving their mess of fecal matter, dropped bits of food, and a foul odor. Pigeons in particular can carry diseases in their droppings that can make people in the building sick.

Signs You Have Drainage Problems

Unfortunately, very often by the time you are seeing signs that you may have a drainage problem, there is already extensive damage.

Damp Spots

If you notice damp spots on your walls or ceilings. This means there is a moisture problem. It can also be from a leaky pipe, but as soon as you notice it, call your roofing contractor.

Musty Smells

Moisture causes mold and mold has a very distinctive odor. Even if you don’t see any other signs, it means you need to have an inspection of your roof and or plumbing.

Excessive Humidity

You may feel like the building is more humid than usual. Extra moisture that is seeping into your roof, walls, and ceiling will cause the humidity to rise. It can also cause doors, windows, and cupboard doors to swell and stick.

Changes in Your Energy Bill

If your energy bills are higher or your heating or air conditioner is working harder, then you need to have these issues checked out. It’s a sign your roof is not doing what it is supposed to do.

Drainage for Commercial Flat Roofs

Problems with your commercial building can mean a loss of money. People need to be able to do their work in a safe, comfortable space. Book your roof inspection today.

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