Flat Roof Maintenance and Repair vs Replacement


Flat Roof Repair Cost


Is your residential or commercial flat roof leaking? If so, do not panic. It is completely normal for your flat roof to require repairs at some point throughout its lifetime. When the repairs become complicated and expensive, it may be a better long-term investment to replace the entire flat roof. PVC, EPDM or TPO flat roof repairs can be very simple and usually do not cost an arm and a leg to fix.

The biggest challenge in repairing a flat roof is finding the source of the leak. Water can travel long distances under flat roof membranes before finally dripping onto the floor inside the building. A flat roofer will usually charge by the hour to find a leak. And of course they will charge to repair where the water is penetrating the flat roof membrane.


When to Replace a Flat Roof Roof vs Repair


If your flat roof is older than 15 years old it may be better to replace the roof. Especially if the repair costs are high. Most flat roofs in the DC area are done with TPO membranes these days. The life expectancy of a TPO roof is 15-25 years depending. The average cost to replace a flat roof in the DMV area is $15,000 for a 15 square roof. Just like it is not wise to do an expensive repair on an old car, the same is true of a roof. Repairs on aging flat roofs can be pricey. And maintenance costs get higher every year.


Why will flat roofs leak?


Sometimes improving drainage systems to get water off the roof faster, will solve the problem. Standing water on top of a roof is a major problem. The longer water is on your roof, the more likely it is to find somewhere to leak into your property.

What are the most common repairs for a flat roof. How much does the average repair to a flat roof cost?

How Much Are the Most Popular Flat Roof Repairs


  1. Drainage Problems– Sometimes all you need to do is unclog your drains. If water is backing up onto the roof because it cannot drain, water has more time to seep into the roofing system and cause a leak. We see this all the time where leafs, branches, cigarettes and other debris blocks water from entering into the drains.
  2. Membrane puncture leaks-  Even when taking the best precautions, your flat roof will develop punctures in the membrane which can be caused by a number of things. The flat roof repair solution for all punctures is to cover the damaged area with the preferred flat roofing repair cement. The cement should be inserted in the puncture as well as the surrounding area. These repairs usually cost between $800-$3000
  3. Leaks at Seams in the Membrane- Flat roof membrane seams contract and expand with hot and cold weather. Over time, the seams come apart and create areas where flat roofs can leak. Repairs to flat roof membranes are simple to fix. More and more seams open over time and at some point replacement will be a better option. Seam repairs are usually easy to perform. And do not cost much. $800-$2000 for seam repairs on an average sized flat roof is common for a 10 year repair.
  4. Leaks around vents and chimneys-  When you have a leak originating from around a roof penetration it can be because of one of two things. Either the roofer you hired did a poor job and installed the flat roof flashing incorrectly or stress overtime combined with outdoor conditions wore it out. Either way, new membrane reinforcement around the leaky penetration needs to be done. The costs usually range from $500 – $1500 per penetration. Often determining which penetration is leaking can be difficult and you may end up re-doing all of them which can get a bit costly.


Membrane puncture is the most common flat roof repair


The most commonly reported flat roof leak is due to membrane punctures. This will require the recommended flat roof repair material and cement to be spread in and around the punctured area to seal the leaky defect. The average cost to repair a flat roof solely depends on the severity of the damages and the amount of surface area that is affected. You could be looking at anywhere between $800-$5000 for flat roof related repairs. The average flat roof replacement cost is $15,000. As a roof ages and repairs costs increase, it may make more sense to replace the roof.


Why are Flat Roofs More Likely To Leak


Flat Roof Repair Cost


Flat roofs can be commonly found on top of commercial buildings and residential row homes in the DC Metro area. These roofs have very little grade or slope which causes water run-off to move slower compared to a standing seam metal installations. Flat roofs are more likely to leak due to the fact that they are unable to shed water as well as other roofing systems including slate tile roofing systems and shingle roof installations. Water does not drain as quickly, so there is more opportunity for water to pool and penetrate the roof membrane and seep into the roof system. Although your roofing system looks relatively flat from almost all perspectives, it is not actually entirely flat or at least shouldn’t be. All flat roofing systems should be sloped between 1-10 degrees depending on your local building code. The slight slope should move water towards the drains and away from the walls and foundation of your home or building. 

How Do Flat Roofs Drain


flat roof repair cost


It’s no secret that flat roofs are more resistant to severe weather conditions compared to other roofing systems. But when it rains or snows, where does it go once it all falls? Flat roofs are not able to use their slope or the power of gravity to remove water as efficiently compared to a shingled roof. They need a specifically designed drainage system to get the job done. Let’s take a look at the two most commonly used flat roof drainage systems:

  • Interior Drain  – An interior flat roof drainage system is commonly found on larger commercial flat roofing systems, but can be used for your residence as well. With the slight slope of a flat roof, water will flow similar to how sump pumps and drain tiles are designed. The water will flow into the drain into an internal series of pipes which are located beneath the roof. Then the water is carried out and pumped out and away from the foundation of your home or commercial building.
  • Scuppers – This flat roofing drainage design is simply just large square gaps located in the curbs or walls along the building’s roofline. Scuppers allow water to flow throughout the sides of the building. It is common to install downspouts directly below the opening to catch and divert the water away from the foundation of the building.


Walking Creates Unwanted Stress On Your Flat Roof


This is the most popular cause to membrane punctures. As commercial flat roofs hold heavy equipment like HVAC systems and exhaust fans, there isn’t any room for extra weight. Meaning, when HVAC technicians go up there and service the system, the roof membrane around that area becomes more stressed than it already is. In addition to that, equipment and tools can be easily dropped. The combined stress of the foot traffic with the impact of dropped tools can easily produce tears and/or punctures in the roof membrane.

Weather and Wildlife Can Easily Ruin Your Flat Roof


Weather plays a key role in damaging/destroying all roofing systems including cedar and asphalt shingles. When specifically discussing flat roofs. Hail can easily puncture through the membrane and strong winds will pull up the layers. Completely leaving your home or commercial building exposed. Bigger storms will also blow debris around and displace equipment, causing different things to get thrown around in ways that will harm your flat roof system. Animals like squirrels, raccoons, birds, and even in some cases cats love to explore roof tops. Unfortunately, their sharp claws or nails will easily scratch and puncture the membrane. Causing you to find and call a roofer to repair your flat roof.


Premier Roofing Solutions Flat Roof Service


If you are looking to install or are experiencing leaks from your flat roof and live in the DC metro or Maryland area, give us a call. Our specialized flat roof service team is ready for any and all flat roof related tasks you may need. Do not hire an inexperienced roof contractor to work on your flat roof project. Here at Premier we have over 25 years of experience and are ready for any project that comes our way.