Flat roofs cost less than pitched roofs because they lack big slopes, requiring fewer labor hours and materials to install. As a result, flat roofs are some of the most affordable options available, with materials that can last longer than standard asphalt shingles.
While flat roofs are generally less expensive, determining the exact cost of your installation can be difficult. This article will help simplify this problem by reviewing the price of every major type of flat roof on the market. In researching this article, we looked at pricing data provided by contractors and industrial suppliers, then compared this information with current public market trends.
- You can expect to pay around $4–$6 per square foot for a flat roof replacement.
- There’s a variety of roofing materials for flat roofs that impact the total cost you’ll pay.
- Replacing or installing a flat roof is not a DIY task—we definitely reccomend hiring a pro.
What Is the Cost of a Flat Roof Installation?
A new flat roof costs between $4 and $6.94 per square foot. This cost includes labor hours, overhead, and materials. Therefore, you can expect to pay $6,800 to $11,798 to replace a 1,700-square-foot flat roof, which is the typical size of a roof in the U.S.
Because of the wide variety of materials available, this price can fluctuate tremendously, ranging from as low as $2.92 to over $13 per square foot. Here is a more in-depth breakdown of the national average cost of flat roofs:
|Cost Level||Total (Per Square Foot)||Project Total (For a Roof That’s 1,700 Square Feet)|
|Low-end Cost Range||$2.50–$3.91||$4,259–$6,647|
|National Average Cost Range||$4–$6.94||$6,800–$11,798|
|High-end Cost Range||$8.97–$13.00||$15,249–$22,100|
We retrieve cost data from RSMeans, a project estimator for contractors and home improvement experts. The average costs listed in this article include materials and labor fees.
What Is the Cost of a Flat Roof by Type?
Material type is one of the key pricing factors in any roofing project. Each material has its baseline price, and some are more difficult to install or require unique skill sets, resulting in higher rates for labor costs. Below we outline the most common flat roofing materials on the market, their total price, and their pros and cons.
|Roof Material||Total (Per Square Foot)||Project Total (For a Roof That’s 1,700 Square Feet)|
|Built-up Tar (BUR)||$5.18–$8.32||$8,806–$14,144|
Fiberglass or Glass Reinforced Plastic (GRP)
Fiberglass is an excellent middle-of-the-road option. It’s lightweight, waterproof, and less expensive than traditional roofing materials, with a relatively long life span of 20 to 50 years. Its material cost is extremely low, typically only $1 to $3 per square foot, but its installation cost is usually at least twice that.
The only major downside to fiberglass is that it requires more maintenance than other flat roofing materials. Since it’s composed of glass-based sheets, it’s fragile, doesn’t stand up well to impact, and requires recurring roof inspections.
For more information about this material, read our full breakdown of fiberglass shingles costs.
Metal is a standard flat roofing material frequently used for residential and commercial buildings. Numerous metal roofs are available, with a wide range of associated costs. The most common material for metal flat roofs is aluminum, which typically runs from $3.88 to over $5 per square foot. However, some materials, like steel, can go as high as $15, and luxury metal roofs, like copper, can go up to $30.
Flat metal roofs are prized for their durability, water and fire resistance, low maintenance, and moderately low cost. These roofs also have a long life span, ranging from 30 to 50 years, with proper care.
Ethylene Propylene Diene Monomer (EPDM)
EPDM is one of the most popular rubber roofing materials on the market. It’s a synthetic rubber membrane that is highly durable, heat resistant, waterproof, and low maintenance. Some variations are energy-efficient, reflecting sunlight and trapping heat, allowing you to save on energy bills. EPDM has a low material cost, only around $2 to $3 per square foot, but labor and overhead typically bring its total cost to $4 to $10, with some prices as high as $13.
EPDM’s life span will vary depending on your location. Northern states, with less sun and more moisture, tend to have EPDM last longer, potentially 30 to 50 years, but warmer, dry climates can expect between 15 to 20 years.
Polyvinyl chloride, or PVC, is a synthetic plastic used to create many items, including pipes, fasteners, and roofing materials. In roofing, PVC takes the form of a single-layer, rollable membrane. It’s more commonly used on commercial buildings but still frequently sees use in residential projects. It’s heat resistant, waterproof, energy-efficient, easy to install, and inexpensive.
PVC’s material cost is only around $2.60 per square foot, but labor and overhead bring this number to $4–$8 per square foot. While PVC has one of the most consistently low prices for roofing materials, it doesn’t last as long, with a shelf life of only 15 to 30 years. Some homeowners report their roofs lasting longer, but these are usually under ideal conditions with constant upkeep.
Thermoplastic Polyolefin (TPO)
The last of our synthetic options is Thermoplastic Polyolefin or TPO. Like PVC and EPDM, it’s a single-ply membrane, synthetic sheet that is rolled on. It’s efficient, waterproof, long-lasting, fire-resistant, and durable. However, unlike other entries on this list, it’s created from recycled materials and is typically recycled when replaced, making it an eco-friendly alternative.
TPO has a moderate life span of 20 to 30 years, but some homeowners have reported longer with good upkeep. Its price is on the lower end at $3–$8 per square foot, a remarkably low price point for its life span.
Built-up Tar (BUR) and Modified Bitumen
Built-up roofs and modified bitumen roofs use layers of synthetic materials (typically felt), gravel, and tar to create a strong waterproof coating. They’re highly fire-resistant, water-resistant, and durable while requiring little maintenance. Modified bitumen is the more modern of these two roofs and sees residential use, but some companies still go with BUR.
Unfortunately, these roofs don’t last long, with most having a 10 to 20-year life span. These roofs are priced at around $5.18 to $8.32 per square foot.
What Does a Flat Roof Cost by Size?
Once your material is picked out, your flat roof project’s next biggest cost factor will be its square footage. Thankfully, these roofs have a much lower total square footage than standard homes due to their lower slope. Below are some average prices for flat roofing projects based on common roof sizes.
|Roof Size (In Square Feet)||Price Range||Average Cost|
How Much Does a Flat Roof Cost by Materials?
While trained professionals should handle most roofing projects, there may be situations when you need to repair or install parts of your roof by yourself. In this situation, you’ll need to purchase materials from industrial suppliers or home improvement stores. Here is a quick breakdown of what you can expect to pay for each type of material.
Remember that most roofing materials are sold in squares or bundles (packages with enough contents to cover 100 square feet), but flat roofs differ. Metal roofs, for example, are sold in sheets, while products like PVC, EPM, and TPO are all sold in large rolls.
Depending on your roof’s materials, you may need to buy additional sealant and underlayment. Sealant can cost you an additional $1 to $5 per square foot, and underlayment is about $1.60 to $4 per square foot.
|Material||Baseline Total Material Cost (Per Square Foot)||Total Material Cost for a 1,700 Square Foot Roof|
Which Factors Impact How Much a Flat Roof Costs?
Square footage and materials are the two primary cost determiners of any roofing project. However, numerous other factors can impact your bill’s total. For flat roofs, removing the old materials, add-ons, repairs, and required permits can add a surprising amount to your final price tag.
Old Roof Removal
If you’re replacing your existing roof, it must be properly removed and disposed of to make room for the new one. Thankfully, most contracting companies can take care of that for around $1 to $5 per square foot. As a result, you can add $1,700 to $8,500 to your final bill for a moderately sized roof. Remember that this price can vary depending on your area and local waste disposal laws.
Add-ons and Repair Costs
Sometimes, roofing companies may come across damaged roof sections during a replacement. When this happens, they typically contact the homeowner, get permission to make repairs, then generate an updated quote that includes the additional service costs.
Additionally, many homeowners opt to make additions or updates to their roofing systems during replacements, like repairing their gutters, attic, and drainage system or adding a skylight.
Here are some of the most common additions and repairs homeowners may come across and their associated costs:
- Repairing or replacing flashing: $10–$27 per linear foot
- Roof sealing: $1–$4 per square foot
- Gutter repair or replacement: $1,000–$7,000
- Adding a skylight: $900–$2,500
- Repairing a chimney: $150–$1,000
You’ll need to acquire a permit for any major home renovation or repair, like installing new plumbing, a roof, or undergoing major electrical work. Thankfully, most contractors handle acquiring permits for you, but in doing so, they’ll add a permit fee to your quote. You can expect to pay between $150 to $500 for permit fees from a contracting company.
Benefits of Investing in a Flat Roof
Investing in a flat roof has many benefits, but the largest is a significant cost reduction. Flat roofs have much less square footage than normal roofs due to their lack of slopes and raised sections. As a result, a flat roof installation will have less material and labor costs.
On average, a flat roof will have about 13% less square footage than a standard roof of a home with the same base size.
Professional Vs. DIY Flat Roofing Cost
You’ll want to go with a professional roofing company when installing a new roof or replacing an old one. While installing a flat roof is easier and safer than working on a standard sloped roof, it’s still extremely difficult and skill-intensive.
The materials used in flat roof installation are often toxic and dangerous to handle, such as hot tar or welding equipment. Using these materials properly requires special training and experience, which without, can result in personal injury or an improperly installed roof.
Doing a Flat Roof Installation Yourself
While installing a new roof is beyond the scope of most homeowners, it’s possible, albeit not recommended, that you can replace certain flat roofs yourself. Keep in mind that a roof is only as good as its installation and that an improperly placed roof can lead to water damage, mold, and other serious problems. Furthermore, even on an easier-to-navigate structure like a flat roof, roof work is still dangerous, and you should take every possible safety precaution.
If you’re going to install a flat roof yourself, you should pick a material that is easy to handle and doesn’t contain overtly harmful materials. You’ll want to avoid fiberglass, BUR, and flat metal roofs; each has dangerous materials or specialized skill requirements that make them not suitable for most homeowners. Instead, your best bet will be a good, single-ply roofing, like EPDM.
Hiring a Professional for a Flat Roof Installation
A roof is a lynchpin structure; if any part fails, it can damage other parts. As such, picking the right roofer for your next installation is critical for the long-term well-being of your home. If you’ve never hired a roofing contractor before, this process can be intimidating; but by following these simple steps, you can find the right pro for your next flat roof installation:
- Find local experts near you: Begin by looking for the most reputable local roofing contractors; check their customer reviews, Better Business Bureau rankings, and state licenses before the next step.
- Get a quote from a few options: Once you’ve selected several, schedule a time to get in-person quotes from each one.
- Consult them about their recommendations: Be sure to speak with them about the job during the quote process; this lets you assess their customer service and get information about your project.
- Review quotes: Check the quotes you received, comparing their charges and overall prices.
- Select a final company: Once you’ve made a selection you’re comfortable with, it’s time to schedule an appointment for your new roof installation.
What Is Our Recommendation on Flat Roof Installation Costs?
There are many great options for flat roof installations. We think metal roofs, TPO, and EPDM are excellent choices. Each of these roofs has a long life span, requires little maintenance, and has reasonable price ranges. While fiberglass is also low-cost, it’s fragile and can need frequent maintenance. Furthermore, BUR roofs are, on average, more expensive than single-layer roofs and don’t last nearly as long. Overall, flat roof replacement costs will run you between $6,800 and just under $12,000. Factors like materials, square footage, and any additional repair work can change this number, but even still, you’ll be paying significantly less than a pitched roof replacement.
FAQs About Flat Roof Installation
Are Flat Roofs Expensive?
Like all roofing projects, flat roof installations have the potential to be expensive. If you choose a high-cost material, like steel or copper, and have a large area to cover, you’ll have a hefty bill once the project is completed. However, flat roofs cost less on average than standard shingle roof installations.
What Is the Cheapest Flat Roof?
For installations, the cheapest average flat roof will be TPO. In pure material cost, EPDM is the cheapest.
What Is the Life Span of a Flat Roof?
A roof’s life span depends on location, material, and upkeep. The typical flat roof lasts 15 to 30 years, but some materials in the right climate can last much longer.
Do Flat Roofs Have a Slope?
All roofs need a slope, even “flat” roofs. If a roof lacks a slope, water, snow, and debris can build up and cause problems. Your standard flat roof has a slope of one-fourth of an inch per 12 inches.