Last Updated on March, 2025
A flat roof deck allows you to use the extra space. Flat rooftops can be used for a sunset barbeque or a get-together. A flat roof is also less costly and will let you get away with saving a lot of money and time.
Despite these benefits, flat roofs have some issues. They don’t require much maintenance. However, if you don’t monitor your house’s drain system regularly, you will start seeing signs of problems with your flat roof.
Nevertheless, it is best to look for these signs and tend to them as soon as possible before your flat roof starts leaking.
Quick Summary
- To prevent flat roof leaks, it is important to choose a reliable flat roofing contractor, conduct regular inspections, address drainage issues, properly install features like skylights, and handle structural issues promptly. Temporary fixes can also be used until repairs can be made. Regular maintenance is crucial to prolonging the life of a flat roof.
- Flat roofs offer extra space and cost and time savings, but require regular maintenance to avoid issues.
- Common causes of flat roof leaks include deterioration of roofing materials, thermal movement, installation faults, pooling water, issues with seams, blisters, lack of maintenance, and natural damage.
Why is My Flat Roof Leaking?
If your flat roofing also has HVAC units or vulnerable spots for plumbing leaks, they increase the chances of leaks from roofs. However, a flat roof leak can also be caused by several other reasons.
Unlike a shingled roof with at least a slight slope, a flat roof has space to collect water and harbour further issues, so if you are questioning why your flat roof leaks, we’ll tell you all the most common reasons behind it.
Deterioration
Choosing the best flat roofing materials and the roofing contractor is essential. We also can’t deny that all roofing materials deteriorate with time. The flat roofing system is for homeowners who can invest in a roofing structure every few years if they see any signs.
If you don’t do regular roof inspections after some days of harsh weather conditions or sudden impacts such as falling trees, it will put enough stress to kickstart the deterioration. The bottom line is that if your flat roof leaks, it is very likely near the end of its life.
Thermal Movement
It’s been a practice to use oxidized bitumen as an adhesive to add a rubber roofing membrane. This flat membrane serves as a protective layer to the flat roof. However, it also causes cracks and splits on the roof’s surface.
The stiffness of the oxidized bitumen causes wear and tear. The unexpandable roofing material prevents thermal movement in the flat roofing membrane.
To avoid this, some professional roofers have started using expansion joints. The joints allow movement to prevent membrane wear and tear.
Installation Faults
Considering all the factors, you must choose a professional roofer who ensures it is properly installed. An improperly installed flat roof can’t be properly maintained, and it must be properly sealed to prevent flat roof leaks.
Hiring a professional roofer with the best experience may be more expensive, but it will be worth it because flat roofs require detailings around the drain systems and roof vents. The details prevent leaks.
Another fault from improper installation is delamination. It happens when the layers of flat roofing material are not sealed properly. The layers separate, causing splits and cracks, eventually leading to a leaky roof.
Pooling Water
A pitched roof prevents pooling water. A functional roof needs a pitch of at least 1:40 to prevent proper drainage issues after rainfall. If water stays on a leaking roof for more than 48 hours, it seeps into the ceiling.
Even if it has a very slight slope, you need an occasional thorough inspection. The water can pool along the roof’s edge, causing the same issues.
Issues With the Seams
An overlapping or uneven seam causes a leaking flat roof. This problem is usually avoided if you hire an experienced roofer. An EPDM membrane on the whole roof prevents water from getting in between the uneven seams.
Having that to seal the weak points saves you for some time, at least, despite the poor workmanship.
Disturbance in the membrane due to joint expansion for too long can shrink the membrane. This becomes an issue when the stress becomes too great for the seam, and you need to replace it.
Blisters
Blisters happen when water seeps into the roof, and you can see a bubble-like texture. The bubble or a blister is a sign that your roof’s membrane is nearing the end of its life. Be cautious of blisters, and get your routine roof inspections.
Use high-quality materials for your new roof to avoid blistering. Blisters are raised because water vapors evaporate and have nowhere to escape. Damp timbers can also cause blisters. Whatever the reason, it’s time to start the flat roof repair.
Lacking Maintenance
Whether it is a commercial or residential roof, if it is installed correctly, lack of maintenance is the most common reason behind a leaky flat roof.
It is expected to have a cleaning staff for commercial roofing, which helps. However, roof maintenance is essential to all kinds of buildings. Maintenance staff should check the roof regularly when there are flat roofing features like a skylight.
Skylights and Debris
Skylights are a major reason behind flat roof leaks. They need to be fixed properly. The skylights need to be installed with saddles up-slope from the curb so there is no space for water.
Debris can cause issues with skylights. If they crack at any moment, call for flat roof repairs. Often, if a tree looks over your flat roof and you find fallen branches, check the roof’s membrane for even a tiny hole. Even a tiny piece of debris can penetrate and cause issues later.
Natural Damage
Natural damage can happen to your flat roof. If you live around trees or in extreme weather conditions, hailstorms or too much heat can cause the membrane to tear and allow leaking flat roofs.
Structural Issues
If your flat roof doesn’t have a pitch, that is a structural issue. If debris blocks gutters, poor flat roof installation prevents water from flowing out.
Sometimes, a roof deck is overspanned because you have skylights and other roofing features. Structural issues can’t be solved with temporary fixes. If a professional tells you there are structural issues, you must redesign your flat roofing system.
Useful guides:
Warning Signs of Flate Roofs Leaking to Lookout for
You must pay attention to the details to catch these signs. Some are more obvious than others. If you suspect something and get it repaired as soon as possible, you won’t need a flat roof replacement.
- Dark Brown Patches: If you encounter a dark brown stain-like botch on the ceiling, pooling water seeps into your ceiling. You don’t need to panic, but if you don’t fix it, it may bleed into the rest of the ceiling and make matters worse.
- Roof Sagging: You may notice your ceiling dipping from one corner. It won’t need replacing immediately, but it is a sign that the timber is starting to rot, and eventually, it can give out.
- Low Spots: A low spot occurs in wet weather. When there is a greater chance of water puddles on your flat rooftop, you must pay attention to proper drainage. The stress on the structural integrity of your building may cause costly repairs.
Find Where the Leak is
The first step is to find where the roof leak is. This can be tricky because a blister or discoloration on the ceiling doesn’t mean the leak is in the same spot. Unlike sloped roofs, the water can spread and seep into different layers when flat roofs leak.
Even if water is dripping from the ceiling, it doesn’t indicate the leak is directly above the spot. You can find the spot only with a thorough inspection of the roof. If you find any cracks in the rubber membrane or splits in the roof, that is an easy find.
But it is not; it could be your waterworks. Check it before it disturbs any of the gas lines in your house’s structure. You can also look for low spots with a ring of dirt around them. Once you find the area, spray it with a hosepipe and let the water seep into the flat roof layer.
Wait some time and check if the water is leaking from that area. If so, then that’s the point at which you should start your flat roof repair.
Can You Temporarily Fix the Flat Roof Leak?
Flat roof leakage is a big problem, but if you are in charge of a commercial roof at a workplace or something similar, you must find a temporary fix ASAP. The same goes for residential roofing.
You can put a bucket under the dripping water if that’s the issue. But you can do that for only so long. At some point, if you can’t immediately start the flat roof leak repair, you can use these three fast temporary fixes.
- Flat Roof Sealant: Get a contractor to apply flat roof sealant on your roof. There are many versions of flat roof sealants. Ultimately, you need an experienced roofer to do this job for the best results.
- Polyurethane Material: Polyurethane is a plastic that can be used as a sealant to temporarily fix a leaking flat roof. It is becoming popular due to its composition and its shorter drying time.
- Self-Adhesive Rubber Tape: If you find the exact spot of the leak, you can use a self-adhesive rubber tape. This should give you enough time until you replace the flat roofing.
Contact Bristol Roofers for Leaking Flat Roofs
Bristol Roofers is your best choice for local roof repair and replacement. We offer our services the same day you contact us. Our prices are upfront and discussed before considering all the possible solutions.
All our technicians have years of experience. So, they can recognize the issue and give you a solution.
How to Avoid Flat Roof Leaking?
You can avoid this painful situation by taking some steps. We give our customers maintenance suggestions to ensure their flat roofing systems last a long time without any issues.
- Do the most research before hiring a roofer. Poor installation sets you up for the ultimate failure in much less time than a properly installed roof.
- Inspect regularly. Look for any stress on the roof’s membrane and flashings. Even a tiny crack can make things worse.
- Look out for blocked gutters. A blocked gutter is a recipe for disaster. As soon as the water leaks into the layers of your roof, it starts deteriorating.
There are many reasons for a leaking roof, most of which can be avoided with simple maintenance. If you live in an area with extreme weather, snow, freezing, and thawing winds, then your roof will be stressed.
If the sun is extra strong where you live, the heat will cause tears if there are no joint expansions to help the roof.
The bottom line is that at some point, your roof will start to leak. This could be caused by natural conditions, or it could wear out over time and reach the end of its life. You can only prolong its life by taking care of it.
The best option is to get professional maintenance help. At Bristols Roofers, we provide regular maintenance to help you get the most out of your roofing system.
