Updated: October 7, 2025
Written by Laura Madrigal
Nieves is a home remodeling editor at Fixr.com with special interest in landscaping, pest control, painting, installation, and repair projects. She brings her work ethic, creativity, and love for teamwork into everything she does, including working with writers and designers at Fixr.com to develop useful and comprehensive guides for homeowners.
Learn moreReviewed by Nieves Martinez
The national average cost for professional flat roof repairs is between $300 and $1,100, with most homeowners paying around $700 for flat roof leak repair, the most common type of repair. You could pay as little as $150 for a small patch on a built-up roof or EPDM roof, while large-scale repairs can cost as much as $4,000.
Flat roofs are commonly found on both commercial buildings and contemporary-style homes. Because there is little to no pitch or slope on a flat roof, they tend to develop issues relatively quickly, requiring repairs every few years. Factors that will affect your repair or roof replacement overall cost include how large your roof is, the type of material it's made with, the complexity of the issue, and local labor prices.
The best way to find out how much your flat roof repair would cost is to request a quote from a local roofing company. You can click below to get started.
Cost of Flat Roof Repair
Flat Roof Repair Cost per Square Foot
Roof repair specialists and companies usually decide how much to charge for their services based on the problem and how long the repair will take, so flat roof repair costs per foot aren’t common. However, the size of the damaged area can be an important factor for estimating your flat roof repair costs.
Expect to pay from $2 to $10 per square foot for professional flat roof repair. The table below shows the average repair costs based on the square footage of flat roofing that needs repairs.
Size | Average Repair Costs |
25 sq.ft. | $50 – $250 |
50 sq.ft. | $100 – $500 |
75 sq.ft. | $150 – $750 |
100 sq.ft. | $200 – $1,000 |
150 sq.ft. | $300 – $1,500 |
200 sq.ft. | $400 – $2,000 |
500 sq.ft. | $1,000 – $5,000 |
Cost to Repair a Flat Roof by Type of Material
Flat roofs can be made from many different materials, and some are more expensive and time-consuming to work with, leading to higher repair costs. For example, built-up roofing is easy to patch and takes minimal time, whereas patching an EPDM roof and sealing the seams takes longer and comes with higher labor costs. The table below provides repair average repair costs for the different flat roof materials to give you an idea of what your repair will total.
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Material | Average Repair Cost per Sq.Ft. |
Built-up | $3 – $7 |
Fiberglass/GRP | $3 – $8 |
Modified bitumen | $3 – $8 |
Concrete | $4 – $15 |
EPDM | $5 – $10 |
Metal | $5 – $15 |
Built-Up
Fixing a built-up roof or built-up tar roof ranges from $3 to $7 per square foot. Built-up roofs are similar to modified bitumen roofs and have the same pros and cons. They are affordable, versatile, and easy to install, but they can be prone to impact, storm, and water damage if water pools on top for too long. Patching a BUR is a bit easier, though, and more affordable.
GRP or Fiberglass
The cost to repair a flat roof made of glass-reinforced plastic (GRP), also called fiberglass, ranges from $3 to $8 per square foot. Fiberglass is one of the most affordable materials for a flat roof, and it’s relatively easy and affordable to repair, as well. While fiberglass roofs withstand general weather conditions, wear and tear, and leaks well, they tend to crack, break, and dent from temperature swings or impact.
Modified Bitumen
Repairing a flat roof made of modified bitumen averages $3 to $8 per square foot. Modified bitumen is a popular, affordable material for flat roofs, well-known for its versatility and resistance to extreme temperatures and UV rays. However, modified bitumen roofs are at risk of damage due to debris and impacts from hail and falling tree branches. Pooling of water on a modified bitumen roof can also make it wear down quickly.
Concrete
Expect to pay between $4 and $15 per square foot for concrete roof repair. Concrete is one of the strongest materials used for a flat roof, and it stands up extremely well to impact and foot traffic. However, cracks and fissures may appear in a concrete roof over time, which need to be filled in to prevent water from penetrating or ice freezing inside the gaps. It can cost a lot to repair flat concrete roofs if old and crumbling sections of concrete need to be removed before new concrete can be poured.
EPDM
Homeowners spend between $5 and $10 per square foot on EPDM flat roof repairs. EPDM stands for ethylene propylene diene monomer. This strong and tough material can either be secured with fasteners or fully adhered, and a ballasted EPDM roof is possible, too. It stands up well to sun and water but may shrink with exposure to UV light or extreme temperature fluctuations, leading to surface tears and cracks that need patching and treatment with adhesive.
Metal
Metal roof repairs average $5 to $15 per square foot. Various materials are used in metal flat roofs, including aluminum and steel, and metal roofs are known for their strength and solidity, lasting decades with minimal maintenance. However, changing temperatures can cause the fasteners and parts of a metal roof to expand and contract, potentially leading to pieces falling out of place or suffering damage that requires repairs.
Flat Roof Repair Price by Area of Repair
Many different issues may arise with a flat roof, and the total costs of flat roof repair are highly dependent on where you’re experiencing an issue. Some repair jobs are quick and simple, requiring minimal work, while others are more extensive and difficult, which drives up labor costs. Below are some of the common types of repairs you may run into with a flat roof.
Type of Repair | Average Repair Costs |
Drain | $70 – $500 |
Drip edge | $150 – $600 |
Flashing | $200 – $750 |
Seam | $200 – $1,000 |
Membrane | $250 – $1,750 |
Drain
Flat roof drain repair costs between $70 and $500 and is a common repair needed for this roof design. As the name implies, flat roofs are mostly flat and can easily accumulate water if they don’t have a properly functioning drainage system installed.
Drip Edge
Expect to pay from $150 to $600 to repair a flat roof's drip edge. These L-shaped metal pieces divert water away from the roof's edge. While they are usually strong, they can be dented or punctured, requiring repair or replacement.
Flashing
The cost to repair flashing ranges from $200 to $750. Flashing is found around roof penetrations and parapet walls. It can wear down or get damaged during storms, potentially causing leaks.
Seam
Expect to pay from $200 to $1,000 for professional seam repair on a flat roof. It is common for water to penetrate seams, which are the weakest part of certain flat roof types, especially single-ply roof membranes like TPO and EPDM. Repairs often involve treating the seams with an adhesive or sealant.
Membrane
Professional repairs for flat roof membranes cost between $250 and $1,750. Membrane punctures are one of the most common flat roof issues that lead to leaks, especially after severe weather. Cement is spread around the damaged area to seal it, and new roofing materials are placed over the top to fix a punctured membrane. Membranes also suffer from cracks and blistering and may need patching or resurfacing.
Average Cost of Flat Roof Repair by Type of Problem
Many different problems affect flat roofs, and most are caused by weather and extreme or fluctuating temperatures. Others can be caused by accidents, impacts, exposure to UV radiation, or general wear and tear. The most common issue with a flat roof is leaking, which may require a patch to correct the issue. Flat roofs can develop other issues, including alligatoring, blistering, bubbling, and sagging.
The repair method depends on the problem. Fixing a leak is very different from dealing with a sagging roof, and the costs vary accordingly. The table below shows common flat roof issues and average repair costs for each. Some of these ranges are wide because costs vary based on the specific roofing material you’re repairing.
Type of Problem | Average Repair Costs |
Water Pooling | $70 – $750 |
Hole | $150 – $1,200 |
Crack | $200 – $1,500 |
Blistering | $250 – $1,500 |
Alligatoring | $250 – $1,250 |
$150 – $4,000 | |
Sagging | $800 – $2,500 |
Cost to Repair Flat Roof Ponding
If you have water pooling or "ponding" on your flat roof, expect to pay on average between $70 and $750 to fix it. This price range depends entirely on the root cause. For many homeowners, a simple fix is all that's needed, such as clearing a clogged drain or repairing a minor broken seal. However, in some cases, ponding can be a sign of a much more serious underlying problem, like a sagging roof. This is a structural issue that requires more extensive repair.
Repair a Hole in a Flat Roof
Fixing a hole in a flat roof can cost anywhere from $150 to $1,200, depending on the hole size and how easy it is to patch your roofing material. Patching a built-up roof is typically more affordable than patching a material like EPDM. Holes can be caused by weathering, storm damage, or foot traffic.
Crack Repair
Fixing a crack in the roof ranges from $200 to $1,500, depending on the crack size and your roofing material. Cracks can appear in many materials, including concrete and single-ply membranes, often due to temperature changes.. Flat roof specialists can usually fill in cracks or patch over them, but you may face more expensive repairs if you have resulting water damage.
Blistering
Expect to pay between $250 and $1,500 to repair blisters or bubbles on your flat roof. Blisters are pockets of air or moisture trapped between the roof's layers. If left untreated, they can burst, leading to more significant water damage. The repair involves resealing or covering the area with a new membrane.
Alligatoring
Repairing alligatoring on a flat roof costs between $250 and $1,250. Alligatoring refers to the cracking and creasing of a roof's material as it ages and shrinks, resembling alligator skin. Roof materials that show signs of alligatoring are more likely to rip, tear, and leak. The solution is usually to patch the area with a new piece of membrane or material, but sometimes, you can cover the affected area with a sealant. If this is affecting a large portion of your roof, it might be time for a full replacement instead.
Leaking Flat Roof Repair Cost
Flat roof leak repair costs between $150 and $4,000+. Leaks are a major concern for homeowners because a flat surface prevents water from draining, potentially causing significant damage to your home. Leaks can be caused by problems with seams, rips, or holes. Professionals typically fix them by patching or sealing the affected area.
Sagging
A sagging flat roof costs between $800 and $2,500 to repair. Sagging is a worrying sign in a roof because it shows that the actual framework or structure of the roof is compromised. This may happen for various reasons, such as water damage to the deck or buildups of ice and snow putting too much weight on the roof. If only small sections are affected, they may be repaired with simple reinforcement, but if large parts of the roof are affected, repair costs can be very high because you’ll need new structural beams.
Flat Roof Repair Cost by Method
A range of different methods may be used to repair your roof, depending on the issue. When holes and cracks appear, patching and resealing may be necessary. Resurfacing might be required for situations involving alligatoring and blistering, and resealing can serve as a more proactive approach to damage. Each method involves a different amount of labor and comes with a unique cost.
Patching: Patching is one of the most common forms of roof repair and is used to deal with issues like small cracks and holes in the roof. It can cost anywhere from $150 to $1,500 or more, depending on the number of patches you need.
Resurfacing: Professional flat roof resurfacing or refurbishment ranges from $250 to $1,500, although the costs could climb to $5,000 or more if you need to resurface the entirety of your roof. Resurfacing is the go-to repair method when roofs are old and suffering from issues like blistering and alligatoring. This method helps cover damaged areas with fresh materials, giving new life to older roofs.
Resealing: Expect to pay between $400 and $1,250 for resealing a flat roof. Resealing is vital to prevent water from penetrating the roofing materials and getting down to the deck or into the home or building, so it’s a good idea to budget for this service every two to four years.
Method | Average Costs |
Patch | $150 – $1,500 |
Resurfacing | $250 – $1,500 |
Reseal | $400 – $1,250 |
Labor Cost to Repair a Flat Roof
Hourly rates for flat roof repairs range from $45 to $80 per hour. Labor makes up around 70% of your total flat roof repair cost, putting the average cost of labor at $490. Labor costs can vary based on the complexity and layout of your roof, the number of stories your building has, the roof material you have installed, and the scope of the work.
Emergency Flat Roof Repair Cost
If you suddenly spot your roof sagging or have water coming down into the home through a hole or crack in the roof, it is vital to get emergency roof repairs as soon as possible. Many roofing companies charge extra for emergency same-day service or urgent repairs on holidays and weekends. Expect to pay between $200 and $350 more than usual for this repair.
While this is a higher cost, it's a necessary expense if your roof is in danger of collapsing or a leak is causing significant damage to your home.
Maintenance Costs
Proper maintenance is the best way to prevent the need for flat roof repair and reduce the repair costs when you do need repairs. Maintenance comes with its own pricing, but finding issues early and preventing others can ultimately save you money over time.
One of the best things you can do for your flat roof is to schedule an annual roof inspection to identify problems and potential issues. A roof inspection costs between $75 and $600, in most cases, depending on the size and complexity of your roof, as well as the material. You can also do your own inspections after severe weather and call in a pro to address any issues or punctures.
Another tip for flat roof maintenance is to ensure the surrounding trees are regularly trimmed, removing any overhanging branches. Otherwise, those branches could fall onto the roof during a storm or strong winds, leading to impact damage like cracks and holes. Tree trimming can cost between $250 and $1,800 per tree, depending on the size.
Finally, be sure to keep your flat roof free of debris, and consider having heavy snow accumulation removed to prevent structural damage. These services can vary widely in cost depending on your roof material, roof size, and accessibility. In some cases, you can do the work yourself if you’re very careful not to puncture the roof while you work.
Cost to Repair a Flat Roof vs. Replace
Repairing a flat roof will almost always cost less upfront than a full replacement, but replacements can still be the better option over time in some cases. Flat roof repairs cost an average of $700, while a full replacement costs an average of $8,000. Understanding when to repair and when to replace can help you get the most out of your investment. Here are some tips for when a repair might be a better financial option:
Your roof has 50% or more of its life left: On average, flat roofs last for 15 to 30 years, although some materials, like concrete and metal, last considerably longer. If your roof still has more than half of its life left, a repair is probably a better option.
The damage is localized: If just a small section of roofing was damaged, a repair is a better option. On the other hand, if the roof needs extensive repairs or has damage to several areas, replacement may be best.
Your roof is still under warranty: If you still have a manufacturer’s warranty or a labor warranty in place, repairs are probably going to be more affordable due to the coverage you still have.
You don’t notice other symptoms of roof damage: Water spots on the ceilings in your upper floors and sudden spikes in heating and cooling bills could signify that an issue that appears small is bigger than it seems. If you do notice other symptoms of roof problems, a replacement might suit you best.
DIY vs. Professional Flat Roof Repair
While the majority of flat roof repair costs are for labor, attempting a DIY repair is not recommended. Many flat roof materials require the use of hazardous chemicals or high-heat torches, making the process dangerous for a homeowner. Additionally, mistakes can easily be made, leading to more extensive water damage and energy loss. For these reasons, hiring a professional for flat roof repair is a worthwhile investment. Hiring a professional offers not just an excellent result but also peace of mind, knowing that your roofing systems are in good hands.
Additional Considerations and Costs
All of the factors discussed above will largely determine your total flat roof repair costs, but there are a handful of other, minor factors you should think about, as well as some related things that can affect long-term costs.
Building code: Building codes vary from place to place and state to state. Some impose limits on the number of materials and membrane layers you have on a flat roof. This could mean having to pay an additional $1,000 to $5,000 to remove your old roof before you install the new one.
Insurance: It can be harder than normal to get insurance for flat roofs. Some insurance companies do not cover flat roofs, while others accept them but charge a higher-than-average rate. Research and compare your options to find the best insurance policy for your flat-roof home.
Gutters: If your roof’s gutters also need maintenance or repair, you could negotiate a discount or deal with your flat roofing contractors by asking them to fix the gutters when working on the roof.
Location: Flat roof repair costs vary by location, mostly because the local cost of living drives the cost of labor. Expect to pay more in major metropolitan areas and in states that have a higher cost of living.
Repairing or replacing a flat roof can be a big job. However, since a roof protects the entire home, it needs to be done ASAP. You may not see the same bump in curb appeal as you would for a visible sloped roof, but you will see a return on investment, along with better water protection and energy efficiency, which could lead to lower utility bills.
FAQs
The average cost to fix a flat roof is $700, and most homeowners pay somewhere between $300 and $1,100. Your cost will depend on the size of the affected area, the type of damage, the layout and complexity of your roof, and the flat roof material you have installed. Costs can climb up to $5,000 or more for extensive repairs on large flat roofs.
The most common defect in a flat roof is a leak, which can occur from a failing seam, a crack, a bubble or blister that bursts, a puncture from fallen debris or foot traffic, or just general wear and tear. Water pooling is another common issue with flat roofs, which can result from roof sagging and clogged or damaged roof drains.
Resealing a flat roof costs between $400 and $1,250, in most cases, although the total depends on the size of the roof and the type of flat roof you have. The resealing process involves cleaning the existing material, repairing any damage, and applying sealant, which is specific to the roof material. Resealing can extend the life of your flat roof and reduce the risk of leaks in the interim.
Leaks in flat roofs can occur for many reasons, including punctures from fallen or blown debris, punctures, abrasions caused by foot traffic, failed seams, or even general degradation that stems from UV exposure, old age, or temperature fluctuations. Flat roof leaks are more common on buildings where water pools on the surface, which can result from structural instability or malfunctioning roof drains.
The best way to extend your roof’s lifespan is to keep it in good condition, inspect it regularly, and fix problems quickly. Schedule an annual flat roof inspection to identify problems, get your roof drains cleaned once a year or more often if you have heavy tree coverage in your area, and plan on resealing your flat roof every two to four years. Proper maintenance and timely repairs on your existing roof can delay the need for a full roof installation.