A leaking roof is a common problem for homeowners to deal with, and it can rapidly cause serious damage to the inside of your home. It’s important to find the source of the leak quickly and to take care of it properly. A flat roof is characterized by its lack of a slope, meaning that any standing water on the surface could potentially lead to serious damage if not dealt with promptly. This type of roof often has an extremely long lifespan because there are very few factors that can wear it down.

How To Find A Roof Leak On A Flat Roof?

1. Check Under the Roof

Before you go up to your roof and start inspecting, it’s a good idea to look around on the ground near where the leak is suspected. If there are any puddles of water or dark spots that weren’t there before, then there’s a high chance that you’ve found the source of your leak.

2. Identify the Type of Roofing Material

To find a roof leak on a flat roof, you’ll need to know what kind of material your roof is made out of. There are a few different types that vary in their durability and resistance to leaks:

  • Asphalt shingles
  • Modified bitumen
  • Rubber membrane
  • Built-up roofs

3. Check the Edge of Your Roof

The edge of your roof is one of the first places that you should look when trying to find a roof leak on a flat roof. This is because these types of leaks are often caused by general wear and tear on the edge, meaning that water can enter and cause problems even if it doesn’t get in through a hole.

4. Look for Damaged or Cracked Areas

Asphalt shingles are often installed on top of plywood, which will be visible from the inside of your home if you happen to have an attic. If there is any damage at the edge of your roof, then you’re likely to see water damage on those boards as well.

5. Condensation check

Condensation happens when water vapor inside the air, turns into liquid. If there is a roof leak in your home, the area below will be colder than other areas and condensate can leave watermarks on your ceilings. It is advisable to look for signs of watermarks around the roof, like peeling paint or wallpaper.

  • Is there any noticeable pooling or puddles of water on your roof?
  • Does anything collect at certain spots on your roof, like the edges or corners?
  • Do you have any mold or mildew in your attic or crawlspace?
  • Do you have any discoloration on the ceiling below, particularly near the edge of the roof?
  • Has the paint started to peel away from plywood overhangs at the roofline?

Infrared roof inspection6. Using Thermal

Using a thermal camera, you can easily detect any kind of roof leak. This is because the water in the insulation will show up at a different temperature than your ceiling or walls. It is a quite simple and affordable method to find a roof leak. However, if you’re not familiar with this technology, don’t try it yourself. It’s hard to interpret the images correctly for those who aren’t trained in this area of expertise. Many variables could make an expert’s interpretation incorrect as well, such as the type of insulation.

7. Inspect leaks from the roof gutters

Look in your gutters and downspouts to see if they’re sagging or leaking. When water gets trapped in your gutters, it can lead to trouble especially when there’s a flat roof above. Try the same thing you did with checking for discoloration or peeling paint on plywood boards.

8. Using Roof Probe

One of the best ways to find a roof leak on a flat roof is to use a probe. These look like long, thin rods with electrodes at the end that connects to wires that run back down your roof and into your home. Using these, you can pinpoint exactly where water is coming in and stop it quickly.

9. Inspect the Basement

The leaks that usually occur on flat roofs, generally leak into the basement and cause stains or other visible damages on the walls. You can also check for water spots around cracks or other openings in your walls and ceilings. This is a great way to find a roof leak on flat roofs.

10. Look for Visible Holes

If you’re looking for a roof leak on the tiled portion of your roof, start your search by examining tiling that is missing or damaged (holes) or tiles that are also discolored or curling up at the edges. Pay attention to any areas that have lost their sealant or are being affected by sunlight.

Remedies To A Leaking Flat Roof

1) Keep gutters and downspouts clear

Ensure that the gutters and downspouts are free of leaves, twigs, and other debris. This will go a long way toward preventing water from pooling on your roof and leaking into your home. You may also want to consider having a professional come out and clean if you have a large volume of debris so that the problem doesn’t resurface.

2) Make sure everything is sealed properly

You want to be certain that any flashing around vents, chimneys, and skylights are doing their job. Use roof sealant liberally on all seams, joints, and connections to fill in any gaps that could allow water to seep in.

3) Check the sealant around skylights

Although a flat roof is sturdy, skylights pose a problem because they’re just as likely to leak as any other roof material if not properly sealed. Make certain that all seams, screws, and seals are tightly fastened down and durable to prevent leaking.

4) Repair shoddy workmanship

Inspect the roof where water is entering and look for any area that may have been repaired recently or has been patched up, as this might be a sign of a leaky flat roof. Although it may seem like a small problem now, you don’t want a roofer to simply take a quick patch job over the problem and continue about his or her business. Reputable contractors will come back out and correct their mistakes, but only if you speak up.

5) Use a roof leak detector

Invest in a roof leak detector to reach those hard-to-find areas that you simply can’t see from the ground. This can be an invaluable tool for finding roof leaks, especially if you’re not sure which area is causing water damage or mold growth. You can then take steps to fix the problem, find a contractor, or make the necessary repairs on your own.


Now you have a better understanding of how to find a roof leak on a flat roof. For more information, please contact us to help to take care of your roof leaks. Remember many things can cause water damage and knowing the difference between them is something that requires attention and special skills.

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