How To Find Roof Leak On A Flat Roof

rolled flat roof with pooling water that could cause a leak

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

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

Finding a Flat Roof Leak

Finding leaks on flat roofing systems can be more challenging than it seems.  Flowing water tends to find the best path with the least resistance.  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 a flat roof is clearing any form of debris on the roof. If there are trees surrounding the roof, then it’s best to trim these trees so that leaves, branches, and fruits won’t fall on the roofing system.

Examine Collars and Flashings

Now that debris is cleared off the roof, it’s time to start looking for the leaks.  The first thing to look at would be the 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 it can cause gaps and leaks to form.

Examine Your Gutters

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

If homeowners are in need and cannot located the leak then it would be best to contact a professional.

Long-term Damage


Flat rooftops are not truly ‘flat’ and most will have a pitch of at least 0.5/12 or 1/12. Having a pitch is paramount in redirecting water towards the right gutter systems so that it’s disposed of.  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 a roof which is usually contributed by a roof without a pitch.  If there are too many materials and equipment on the edge of a roof, this can also lead to water being trapped.  The accumulated weight of water on a roof can increase the chances of more leaks forming.


Heavy rain and snow can lead to water and moisture seeping towards the leaks on a roof.  If the supporting structure of your roof is comprised of wooden beams, rotting can easily occur on these beams.  The accelerated rotting of wooden materials can cause sagging and compromise the integrity of the 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.  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 a home. It’s best to find the root cause of your leaks first before incorporating the possible solutions to leaks.  It’s paramount that home owners find the early warning signs of a leaking roof, like bulging and sometimes even rotting.  Again, if home owners are not sure about what can be done about the leaks 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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Matt Kowalis

Marketing Manager for Central Roofing LLC

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About Central Roofing

Central Roofing is a top quality roofing company in Sullivan, IL that likewise operates in Mattoon and Champaign, and the rest of Illinois. We offer a wide array of roofing services to property owners like you. We have been the leading go-to roofing company of homeowners, business owners, and property managers for almost a decade now here in Illinois.

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