Flat roofs are easy to install, offer direct access for repairs, and provide usable spaces where companies can place equipment. When built with high-quality materials and installed properly by an experienced roofer, a flat roof can last from 20 to 30 years.
But as with all roofing systems, there are a few issues that can happen eventually due to wear and tear and the natural elements. Due to their structure, they can be prone to water buildup and leaks. In contrast to a pitched roof that allows for excellent water runoff, a flat roof requires a well-maintained drainage system to allow rainwater and fallen debris to run off and to reduce the chance of mildew and rot.
The protective membrane that seals the roof can often be damaged by excess built-up moisture, punctures, and heavy impacts. Once you understand why flat roofs leak, you can take preventive measures and prolong the life of your roof.
7 Reasons Your Flat Roof Is Leaking
1. Materials & Craftsmanship
The type and quality of materials used to construct your flat roof contribute to its performance. Good workmanship during installation can also help prevent leaks.
Roofing materials and building techniques have improved over the last 20 years, so the more recently your roof was installed, the longer it’s likely to last.
To save time and expense, it is important to hire a roofing professional you can trust to install your roof or fix any existing leaks. Choose a reputable construction company that doesn't cut corners on design and installation, and that is known for using superior materials. That’s why here at EG Flat Roof Leak Specialist, we use high-quality materials to install and repair leaks on flat roofs.
2. Age & Usage
Even the best materials have a limited lifespan, so age is another reason why your roof might eventually start to fail. Wear and tear from UV exposure, falling or scratching tree branches, temperature fluctuations, and moisture buildup all play a part in your roof’s aging process, leaving it vulnerable to leaks.
Flat roofs are useful since they provide additional storage space, but the more your technicians and employees walk on the roof, the quicker it can wear out.
3. Roofing Membrane Damage
A flat roof depends on a thick, durable membrane to protect it from the weather. While these waterproof coatings are made from strong materials such as thermoplastic, bitumen, rubber, and PVC, they can naturally become damaged over time. This is unavoidable, as normal exposure, wear and tear from foot traffic, and repeated damage from heavy rains and snow are the common culprits.
Your roofing membrane can suffer punctures, blisters, tears, and delamination of the membrane layers. If not noticed or addressed quickly, damage to the roof surface can result in leaks and further water damage in your home or building.
If your roof is leaking at the edge, then the most common culprit is your roof flashing. Since flashing is installed along the edges of the roof to prevent water infiltration into the decking and fascia boards. So when flashing is cracked or deteriorated, you might see leaks coming in through the edge or ceiling.
4. Poor Water Drainage
A flat roof has a very low slope, so the water that lands on it sometimes gets stuck on top if you don’t have a proper drainage system set up.
Proper drainage is essential to keep your roof in good condition. A poorly designed roof without correct drainage is likely to experience water pooling on the surface. This standing water weakens the roof’s protective membrane, increasing the potential for leaks.
If ponding water goes unnoticed, your flat roof can start leaking through the ceiling as it passes the other roofing materials. Even as water damage spreads across the building walls and ceiling, it’s not always clear which area on the roof is responsible for the water infiltration. You’ll need a professional to get on the roof for an accurate assessment.
5. Temperature Changes
Every area has its share of weather conditions that lead to roof damage. The most common problems occur when your roof’s protective membrane faces extreme weather fluctuations, extreme heat or freezing cold temperatures, and sustained rainfall.
Heavy snowfall and hail that come with lengthy freeze-thaw cycles can also add to your roof’s wear and tear.
If you stay on top of your roof’s maintenance and have your roof regularly examined by a professional roofer, you may be able to catch leaks before they become serious.
6. Blistering & Cracks
Flat roofs are open to the elements and experience more stress than sloping roofs. This leads to blistering and cracking of the roof surface. Blisters on your roof don’t always result in tears, but these thinned areas are weaker, so you should keep an eye on any blisters or bubbles that form.
Ground instability and shifting can also contribute to cracks in your flat roof, and a good roof design should allow for movement and flexibility. A roof installed without this structural consideration is more prone to cracking.
7. Improper Ventilation
An effective roof design features roof vents that regulate air pressure and temperature, increasing the energy efficiency of your building and preventing moisture build-up.
Without a proper ventilation system, your otherwise durable flat roof will suffer, and leaking is more likely to occur. A professional roofing company should design your roof with ventilation in mind to make sure it’s durable and long-lasting.
How to Prevent a Flat Roof from Leaking
1. Proper Design and Construction
While a flat roof is an economical choice, it’s always a good idea to have your flat roof installed by a company with a good reputation. With a proper flat roof design and the use of quality materials, the problem of leaks will be less likely, and the roof will last longer and perform better.
2. Regular Maintenance
To keep your roof in good condition and avoid future leaks, create a maintenance schedule. Flat roofs are easier to climb onto and walk across, so you can monitor the roof’s condition often and have a contractor perform regular cleaning and maintenance. Be sure to consult with a roofing specialist as soon as you see a major problem.
3. Keep Your Roof Clean
Habitually cleaning debris off the roof and clearing blocked gutters can go a long way toward preserving its condition. Clearing away dirt and moist leaves that build up can also prevent moss and mildew growth and spreading. When small imperfections of the roof surface occur, repair through resealing and patching to avoid a significant issue down the line.
4. Minimize Roof Traffic and Activity
Encourage your employees or technicians to lower the levels of foot traffic on the roof. This can go a long way in preventing damage to the sealing membrane that’s often caused by sharp objects or consistent activity.
Flat roofs are handy for mounting equipment such as HVAC systems and solar panels, so consult with your roofing contractor to determine the weight level the surface can bear. Installing too much equipment on the roof can add pressure to the total structural load.
5. Upgrade Systems as Needed
Once you have invested in a flat roof, it's a good idea to upgrade your system as needed. Your roof membrane will need resealing from time to time using the latest, most effective sealing materials available.
Make sure the ventilation system is adequate and upgrade it when necessary. Changing weather or seasonal trends in your area can also give rise to the need for more roof ventilation to prevent future damage.