Your flat roof protects you from the elements day in and day out, and sometimes it needs a little help along the way. Flat roof repairs are an inevitable part of being a homeowner, and you should be prepared to spend between $300 to $1,175, or a national average of $725, for each repair.
Naturally, not all repairs are the same, and costs will fluctuate based on your needs. Keep in mind that factors like the size of your flat roof, accessibility, and materials will all affect cost. Additionally, different repairs have different price points. A simple patch job costs much less than addressing a sagging roof.
Table of Contents:
- Average Costs
- Cost Estimator By Size
- Other Factors That Affect Cost
- Related Services
- Pro Cost Vs. DIY Cost
- Cost By Location
- FAQ
Average Flat Roof Repair Costs
| National Average Cost | $725 |
| Typical Price Range | $300 – $1,175 |
| Extreme Low-End Cost | $175 |
| Extreme High-End Cost | $2,550 |
Most flat roof repairs fall into the $300 to $1,175 range, but numerous factors can impact your budget and overall costs. Minor repairs such as a quick seam fix or patch job could cost as low as $175. However, if your roof has major damage from extreme weather like hail, a complete flat roof resurfacing can set you back as much as $2,550.
Flat Roof Repair Cost Estimator By Size
Roof size is typically used to determine replacement cost, not repair cost. However, it can be an important factor when determining some flat roof repair costs like resurfacing and resealing. The average costs of flat roof repairs fall between $4 to $15 per square foot, including labor and materials.
| Size | Average Repair Costs |
| 25 square feet | $195 |
| 50 square feet | $390 |
| 200 square feet | $2,450 |
| 500 square feet | $3,875 |
Other Factors That Affect Cost
The average cost of total flat roof replacement is $9,000. While weighing your replacement and repair options, note that there are many factors affecting overall repair costs, including roofing materials, repair type, location, and labor rates.
Flat Roof Repair Cost Estimator by Material
Roofing material is one of the major factors affecting the cost of flat roof repair. Contractors use a range of materials to install flat roofs, and some are more expensive and time-consuming to install, resulting in higher repair costs.
Premium flat roof material like EPDM can cost as much as $5 to $12 per square foot while a more economical material like tar can cost as little as $3 to $8 per square foot.
Let’s look at the most popular flat roofing materials:
- Built-Up Tar
- Modified Bitumen
- Polyurethane
- Fiberglass
- Rubber EPDM
- Thermoplastic Polyolefin (TPO)
- Flat Concrete
- Metal
Built-Up Tar
Built-up tar, or BUR, roofing requires regular maintenance. The economical material comprises layers of tar paper, gravel, and asphalt pitch. These flat roofs are affordable, easy to install, and UV-resistant. However, they are prone to impact and water damage. Repairing a built-up tar roof will cost between $3 to $8 per square foot.
Modified Bitumen
Like BUR roofing, modified bitumen is an economical and popular choice for flat roofs. The heat-sealed material is similar to asphalt and resists UV rays and extreme temperatures. Repairs to modified bitumen flat roofs cost between $3 to $6 per square foot.
Polyurethane
Polyurethane costs between $4 to $6 per square foot to repair. It is an inexpensive and easy-to-install flat roofing option. The spray foam, SPF, material forms a strong waterproof membrane. Polyurethane flat roofs require regular maintenance and patchwork.
Fiberglass
Like many flat roofing materials, fiberglass is another affordable option. The popular material costs between $4 to $7 per square foot to repair. It comprises woven plastic strands and specialty coatings. The downside is fiberglass flat roofs are susceptible to water damage and cracking.
Rubber EPDM
Rubber EPDM is one of the most expensive flat roofing materials. The durable material is easy to install and stands up to all weather conditions. Repairs for the premium material will set you back between $5 to $12 per square foot.
Single-Ply Membrane
Single-ply membranes, like thermoplastic polyolefin (TPO), offer an energy-efficient and sustainable flat roofing option. Repairs cost between $4 to $11 per square foot, and the popular material is waterproof, durable, and UV resistant.
Flat Concrete
Concrete roofs last 40 years or more, making them one of the most durable types of flat roofs. Concrete is waterproof, weather-resistant, and low-maintenance. Repairs cost between $4 to $8 per square foot.
Metal
Popular metal roofing materials include galvanized steel, copper, aluminum, and zinc. The energy-efficient material is long-lasting and low-maintenance. However, repairs are expensive and will set you back between $3 to $15 per square foot, depending on the type of metal.
Flat Roof Repair Cost Estimator by Repair Type
One of the best mottos in life is to always expect the unexpected. The same goes for your flat roof. Flat roofs are ultra-modern, affordable, versatile, and energy efficient. On the other hand, they are also prone to water damage and drainage issues.
No matter what type of roof or roofing material your home has, repair issues can arise. Hopefully, you get off easy with a simple fix, like a cracked flashing repair. However, you also should be prepared for uncommon repairs like a sagging roof.
Here are some typical flat roof repairs and their average costs. Note that these costs will vary depending on your location and the extent of the damage.
Flat Roof Repair Cost Estimator by Repair Method
The type of repair your roofing contractor has to perform dictates the repair method they must use. Common repair methods include patching, resealing, and resurfacing. There is a wide range of price points, depending on the level of work required.
| Repair Method | Average Repair Costs |
| Painting and Patching | $150 – $1,250 |
| Resealing | $1 – $5 per sq. ft. |
| Resurfacing | $275 – $1,350 |
| Torching | $375 – $3,850 |
Painting and Patching
Many flat roofing materials develop holes from impact damage. Patching and painting typically cost between $150 to $1,250. Where you fall on this spectrum depends on the severity of your crack or hole and the type of roofing material your home has. Patching and painting roof leaks are the most common roof repair methods.
Resealing
Resealing, or surface coating, costs between $1 to $5 per square foot, including labor and materials. Surface coating provides a waterproof barrier and protects your roof deck and underlayment from UV damage. Roofers recommend resealing your flat roof every two to four years, depending on your climate.
Resurfacing
Resurfacing is a common repair or rejuvenation method for built-up roofing materials. Ranging from $275 to $1,350, resurfacing uses a wide variety of materials to cover damaged areas on old roofs.
Torching
Many types of materials used on flat roofs involve combining and sealing layers. Torching is one of the most expensive flat roof repairs, costing between $375 to $3,850. Roofing companies expand the lifespan of your roof by using a blowtorch to seal new layers of material onto your roof.
Labor Cost to Repair a Flat Roof
The total cost of your roof repairs combines the cost of materials and labor. Most roofing companies charge per hour with the average cost of labor for flat roof repairs being $50 to $115 per hour.
Typically, labor rates are dependent on your location, the experience of the roofer, and the type of repair being performed. Overall, labor makes up a significant portion of your total repair cost.
Related Services
While you are having your flat roof repaired, it’s a good idea to look into these related services and upgrades.
Gutter Installation
Proper drainage is essential for a healthy flat roof. While you are having your roof repaired, it is a good idea to have your current drainage system inspected. A new gutter system costs an average of $1,275 and will increase the lifespan of your flat roof and foundation.
Chimney Repair
Chimneys are romantic, providing energy-efficient warmth and reduced utility costs. They can also be a source of leaks if not properly maintained. If your roof needs repaired, chances are pretty good that your chimney could use an inspection and repair, too. Expect to spend an average of $635 for chimney repairs.
Skylight Installation
Skylights make a great addition to any modern home. They reduce energy costs and increase natural light. Typical skylight installation costs range from $1,185 to $3,170.
Pro Cost vs. DIY Cost
Most flat roof repairs are best left to the professionals. Working on your roof can be dangerous, but if you feel comfortable on a ladder, there are a few simple DIY repairs you can tackle on your own.
Clearing a drain or patching a small hole yourself may cost less than hiring a professional. Unfortunately, most flat roof repairs, like sagging, torching, or resurfacing, require specialized training and equipment.
If you are one of the brave DIYers, here are some supplies you may need for the job:
| DIY Equipment | Average Cost |
| Adhesive Sealant | $9 |
| Flashing Material | $20 |
| Flat Pry Bar | $15 |
| Ladder | $125 |
| Roofing Cement | $23 |
| Roofing Trowel | $9 |
| Roof Repair Fabric | $17 |
| Rubber Roofing Patch Kit | $35 |
| Utility Knife | $12 |
| Work Gloves | $18 |
| Total DIY Cost | $283 |
DIY repairs are satisfying, but they have a downside. Without proper training, it is impossible to tell if you are fixing the entire problem or simply providing a surface-level improvement. It is always a good idea to have a professional inspect your roof to prevent major problems in the future.
Cost of Flat Roof Repair By Location
Flat roof repair varies widely based on location and the cost of living. Labor and materials cost significantly more in urban areas like Chicago or New York. Additionally, mild climates with longer roofing seasons have lower overall prices compared to regions with heavy snow and ice where the roofing season is shorter.
There is no way to know exactly what your flat roof repairs will cost without receiving free quotes from professional contractors in your area to compare.
FAQ About Flat Roof Repairs
Unless your roof is part of a new construction, there will be additional costs to remove existing roofing materials. Removal and disposal typically cost between $1 to $4 per square foot, while a full flat roof replacement costs on average $9,000 with labor and materials.
Watch for these telltale signs it is time to replace your roof:
• Damaged, loose, curled, missing, or mossy shingles
• Damage or discoloration around vents, chimneys, or skylights
• Sagging areas
• Visible leaks or water damage
• Grit (flakes of asphalt shingles) in your gutters
• Your roof is over 20 years old
• Neighbors are having their roofs replaced
Proper roof maintenance is the only way to extend the lifespan of your flat roofing system. This includes regular inspections from a professional roofing company. Expect to spend between $120 to $320 for a thorough examination of all your flat roof elements and a written report detailing any findings.
Find a Roof Repair Pro Near You
Most flat roofs will last between 15 to 20 years with proper maintenance. This includes routine inspections and timely repair completions. The cost of a repair varies widely depending on location, type of repair, materials, and more, but you can expect to pay between $300 to $1,175, or a national average of $725. If you want to take the guesswork out of estimating your flat roof repair bill, contact a roofing professional in your area.
Main Photo by: W.carter / Wikimedia Commons / CC0
