How To Find Roof Leak On A Flat Roof

Flat roofs are increasingly becoming more prevalent in the United States, especially on commercial and industrial buildings. Aside from giving a multitude of different advantages, this can also leave more room for different materials or equipment on your rooftop.

how to find roof leak on a flat roof

However, there’s really no such thing as a single roof design that can be the be-all-end-all to all your problems. Just like pitched roofs, flat rooftops are also susceptible to different forms of water damage.

But before we do discuss on how we can counter roof leaks on flat roofs, we have to first look at what makes flat roofs different from pitched roofs.

Finding a Flat Roof Leak

Finding leaks on flat roofs can be a bit more challenging than it seems. Flowing water tends to find the best path with the least resistance. If you’re on a flat roof, it’s harder to find where flowing water might flow towards, especially if the roof does not have a pitch and pooling can easily take place.

Clear Debris First

The first step in finding a leak on your flat roof is clearing any form of debris on your roof. If there are trees surrounding your roof, then it’s best to trim these trees so that leaves, branches, and fruits won’t fall to on your tree.

Examine Collars and Flashings

Now that debris is cleared on your roof, it’s time to start looking for the leaks. The first thing to look for your leaks is on your metal flashing and collars. There are usually two layers of flashing with the first being the step flashing and then the counter layer. These types of flashings need to be able to expand and contract together with the roof when it’s exposed to fluctuating temperatures. If there’s too much pressure on these flashings, this can cause gaps and leaks to form.

Examine Your Gutters

Another part of the roof that you have to keep an eye out for are the gutters. In some cases, clogged gutters can cause water to accumulate on your roof or leak out towards your eaves. Additionally, if you see mineral granules on your gutters, this is a sign that there’s an erosion problem on your roofing materials.

If you’re not sure on what are some of the different ways of identifying leaks on your roof, you can always have a professional roofing specialist inspect your roof for you.

Long-term Damage


In most cases, flat rooftops are not truly ‘flat’  and most will have a pitch of at least 0.5/12 or 1/12. Have a pitch is paramount in redirecting water towards the right gutter systems so that it’s disposed of. But in some cases, there are contractors or homeowners who don’t take into account the pitch of their roof.

Pooling can occur when water is trapped on your roof which is usually contributed by a roof without a pitch. If there are too many materials and equipment on the edge of your roof, this can also lead to water being trapped. The accumulated weight of water on your roof can increase the chances of more leaks forming.


Heavy rain and snow can lead to water and moisture seeping towards your leaks. If ever the supporting structure of your roof is comprised of wooden beams, then rotting can easily occur on these beams. The accelerated rotting of your wooden materials can cause sagging and compromise the integrity of your roof.

Fungal Growth

Another form of damage that’s quite prevalent among flat roofs is the formation of mold, mildew, moss or other types of growths. These organic growths tend to leech away at the mineral granules of slate tiles. Moreover, mildew can also accelerate the process of rotting on wooden beams and encourage rusting as it absorbs moisture.

Ultimately, roof leaks can cause several different problems for your home. It’s best to find the root cause of your leaks first before incorporating the possible solutions to leaks. Moreover, it’s paramount that you find the early warning signs of leaking to your roof like bulging and sometimes even rotting. Again, if you’re not sure about what you can do with leaks, then you can always contact your local roofing contractor.

An important thing to keep in mind is the fact that while flat roofs can be designed in a way that it can lessen the likelihood of damage and leaking, the key to keeping it that way is to regularly maintain your home roofing Champaign.

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