How Much Does Flat Roof Replacement Cost? [2025 Data]
Normal Range: $3,308 - $11,483
We provide accurate cost data by surveying Angi customers about their home projects, along with data from reputable sources and interviews with industry experts.
Flat roof replacement costs often span between $3,308 and $11,483, with an average cost of $7,396.
You might spend $4,000–$14,000 on a 1,000-square-foot roof, $8,000–$28,000 on a 2,000-square-foot roof, or $12,000–$42,000 on a 3,000-square-foot roof.
Roofers charge $3 to $7 per square foot for labor.
You can expect to recoup between 50%and70% of the cost of a flat roof replacement.
Flat roof replacement costs $7,396 on average, though it can range from a low of $1,200 to a high of $24,000 depending on the roof’s size, style, and material. Flat roofs have many advantages over sloped roofs; a major one is that they’re easier and less expensive to replace. Learn all the factors that contribute to the cost of a flat roof replacement project.
Flat Roof Replacement Cost by Size
Calculating the size of your roof can help you estimate what a replacement will cost. For a rough approximation, measure the length of your house's exterior, then multiply it by the width to get the size of your flat roof. Consider adding a small percentage to account for any overhangs.
Here are estimated costs by roof size—but keep in mind that the type of roof you plan on replacing, as well as the material, greatly affect your flat roof replacement cost:
Like traditional sloped roofs, flat roofs offer a multitude of material options. Each has its own cost estimate, advantages, and disadvantages. Many roofing materials look similar, so discuss options with your pro. You should decide whether to replace the old flat roof material with the same material or a different one.
Here’s a breakdown of estimated flat roof replacement costs based on material:
Roof Material
Average Cost per Square Foot
Features
Fiberglass
$4–$6
Lasts 25-30 years; not durable
Rubber
$4–$13
Resistant to warm weather and UV rays
Thermoplastic Polyolefin (TPO)
$4–$14
Good at handling water pools; single-ply system
EPDM
$5–$13
Made from oil and natural gas byproducts; 10–25-year lifespan
Built-Up Tar
$4–$10
Fire-resistant; low-maintenance; lasts 30 years
Glass-reinforced polyester (GRP)
$4–$6
Weather-resistant; needs very dry installation; lasts 30 years
There are several types of flat roofs, including cold roofs, warm roofs, and green roofs. The type of flat roof will influence the price you pay for a replacement.
Here’s how much flat roof replacement might cost based on roof type:
Flat Roof Type
Average Price per Square Foot
Features
Cold
$4–$9
Insulation is below the roof deck, typically inside the joists or rafters; a ventilation gap is placed above the insulation; more susceptible to condensation
Warm
$6–$11
Insulation is located on top of the roof deck, above the vapor barrier and below the waterproof membrane; energy-efficient; good moisture control; straightforward installation
Inverted
$4–$9
A type of warm roof with reversed layers, shielding the waterproof membrane from the elements
Hybrid
$4–$11
Insulation is split above and below the roof deck; increased risk of condensation; often used when a full warm roof is not possible
Curved
$8–$15
Low-slope roof that has a gentle curve; has flat roof features but a sloped aesthetic; the slope improves drainage
Tapered
$7–$10
Flat roof with a gentle slope created with tapered insulation boards; the design ensures proper drainage and prevents standing water
Green
$10–$35
Partially or completely covered with vegetation; has layers like a root barrier and drainage system; environmental and economic benefits
What to Expect With a Roof Installation
Cold Roof Costs
Cold roofs have insulation inside the joists or rafters. The area above the insulation is ventilated, most commonly with soffit vents. These roofs are less expensive than warm roofs, but they’re not as energy efficient, and installation can be more complex. You can expect to pay about $4 to $9 per square foot.
Warm Roof Costs
Warm roofs have insulation on top of the roof deck. The vapor barrier goes below the insulation to prevent rot. This option is pricier than cold roofs, but it’s more energy-efficient and often easier to install. These roofs cost around $6 to $11 per square foot.
Flat Roof Replacement Cost by Application Method
Depending on the roof type you choose, you’ll have different application methods. The most common application methods for flat roofs are ballasted, fastened, and fully adhered. Here’s how the flat roof application type might influence your cost:
Ballasted roofs: $1.50 to $2 per square foot
Fastened attachment method: $2 to $3 per square foot
Fully adhered method: $2.75 to $3.50 per square foot
Costs for Flat Roof Replacement Pros
Roofers charge $3 to $7 per square foot for labor, and a flat roof will take around five days of work to complete, depending on the size and complexity of the job. Some roofing materials, such as built-up tar, are more time-consuming to install, so this will impact the overall cost of labor. If you’re quoted a fee based on the total project cost, expect the markup to be 20% to 30% of the job.
Pro Tip
The cost of a new roof is an investment in the future of your home. Weigh your contractor choice decision on trustworthiness, reviews and integrity. Roofing is a trade that is easy to cut corners in order to cut cost, and going with the cheapest contractor is generally a poor choice.
Want to hire a general contractor instead? These pros often have project fees, and their rates are similar to those of a roofing professional. General contractors charge in many different ways, so read the contract carefully before signing.
Additional Flat Roof Replacement Cost Factors
When planning a flat roof project, you should also factor in additional costs, such as demolition work and permits.
Cost of Demolition and Prep
If your roofing pro bills separately for existing roof removal, budget for this service on top of your roof replacement costs. Roof removal costs about $1 to $5 per square foot, or an average of $1,000 to $1,500. Prep involves removing debris, mold, or algae and repairing any damage.
Permit Costs
Depending on where you live, you may need to pay for a building permit to replace your roof. These permits cost between $250 and $600, though this price increases for roofs larger than 1,000 square feet.
Inspection Costs
It’s a good idea to hire a professional to conduct a final inspection after the roof has been replaced. This will ensure that the contractor did good work. Expect to pay between $120 and $300 for this inspection.
Cost of Warranties
New roofs should come with manufacturer warranties for the materials. Assuming the materials are the same, choose the purchase with the longest and most thorough warranties. If you have doubts about the warranty, check online reviews.
Repair Costs for Flat Roofs
Flat roofs can be damaged by debris, foot traffic, excess weight from ice or snow, or high heat and UV exposure. Flat roof repairs are often less expensive than those for other types of roofs. You can expect to pay an average of $400 to repair minor damage to a flat roof.
DIY Flat Roof Replacement vs. Hiring a Pro
A flat roof replacement is too complex for a DIY job, as many things can go wrong. While you can save a couple thousand in labor costs, remember that you’re using your own time as well. Most homeowners lack the expertise required for such a job, and even minor issues like a few inches of a bad seal can spell disaster for your home.
You may be able to work alongside a pro, though. Hire a local flat roofing contractor to avoid improper installation, unnecessary maintenance, or safety risks. Ask if you can learn how to do some of the work while contributing your own time on sections of the job that wouldn’t result in severe consequences if done incorrectly.
Flat Roof Replacement vs. Repair
Flat roofs are more difficult to repair than sloped roofs because they’re often made of rubber-like material that’s rolled out in large sections. If the issue is small, like a bad seal or physical damage to a small section, a roofing professional could remove and replace that section (or reseal it if the material is in good condition).
That said, it sometimes makes more sense to replace the entire roof, even considering the cost. Here’s when you might choose a flat roof replacement:
The repair will cost more than 50% of the replacement.
The repair significantly alters the appearance of the roof.
You can get a good deal on a full replacement.
A warranty or insurance claim will cover a full replacement.
Tips to Reduce Cost While Replacing a Flat Roof
Replacing your roof is a major investment. Saving money requires some finesse, but it’s possible. Consider some of the options below if you’re looking to save a few dollars:
Check your insurance. You may have a valid claim that can be covered.
Schedule all work in the off-season, when contractors may offer lower rates.
Choose budget-friendly roofing materials.
Gather multiple quotes to compare the best contractor rates.
Almost all projects that replace larger pieces of a house—like a roof—increase its value. New roofs are excellent investments, and most homeowners can expect to recoup between 50%and70% of the cost of a flat roof replacement.
Therefore, if a homeowner spends $10,000 on a flat roof replacement, they can expect to see $5,000to$7,000 returned to them in the form of value when they sell the house. Some choose to simply add the repair amount to the total price, and that’s certainly a valid method if you’re selling your home.
How Angi Gets Its Cost Data
Home is the most important place on earth, which is why Angi has helped more than 150 million homeowners transform their houses into homes they adore. To help homeowners with their next project, Angi provides readers with the most accurate cost data and upholds strict editorial standards. We’ve surveyed thousands of real Angi customers about their project costs to develop the pricing data you see, so you can make the best decisions for you and your home. We pair this data with research from reputable sources, including the U.S. Bureau of Labor Statistics, academic journals, market studies, and interviews with industry experts—all to ensure our prices reflect real-world projects.
Want to help us improve our cost data? Send us a recent project quote to [email protected]. Quotes and personal information will not be shared publicly.
Frequently Asked Questions
Flat roofs can last up to 25 years if properly maintained. You can increase the life span of your flat roof by performing maintenance tasks or hiring a pro to handle them for you. Maintenance tasks include sweeping leaves and dirt, keeping drains clear, inspecting for cracks and punctures, and recoating as needed.
Whether or not your homeowner’s insurance will cover your flat roof replacement depends on several factors. First, you need to check your homeowners insurance policy to see what's covered. Generally, policies don't cover replacement due to normal wear and tear or if the need for a replacement is due to lack of maintenance. On the other hand, policies often cover replacements due to accidents or weather events.
Flat roofs are a solid option for people who want extra outdoor space. Flat roofs are very common in other parts of the world and only recently has the U.S. started to see the benefit in the increased space. Flat roofs are also easier to maintain and pose much less of a safety risk, which allows for more DIY work for handy homeowners. Some people also build green or living roofs that grow plant life.
There are several pros and cons of flat roofs. One disadvantage of flat roofs is that you lose potential attic space because it's flat. Flat roofs tend to pool water and because they lack an angle, any leak in the roof—usually due to a bad seal—has the potential to let in a lot of water. They don’t work well in climates with snow. Flat roofs are also structurally weaker than sloped roofs.
Mitchell loves to share his passion for hands-on work at home. His current writing can be found on Investopedia, Citigroup, LendingTree, and more where he provides financial tips on saving, buying, and investing in homes.
Ami Feller was born and raised in Marshalltown, Iowa. While attending Iowa State, her brother Scott started a roofing crew during the summers, and Ami went to work for him on the crew, eventually becoming the crew foreman. In 2016, Ami split off on her own and opened Feller Roofing of New Braunfels, which was renamed Roofer Chicks in 2021.
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