Thinking of Spraying Foam on Your Flat Roof? Pricing Factors to Know
Last Updated: November 14, 2023
Fact Checked By: Ryan Maguire
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Sprayed Polyurethane Foam (SPF) has been used as roofing material only since the 1970s, making it a relative newcomer to the roofing market.
But other than the fact that it doesn't have a long track record, you'd be hard pressed to find many complaints about this low-slope roofing material.
Offering a low installation cost, weatherability, and virtually maintenance free upkeep, spray foam roofing has a lot going for it.
Spray Foam (SPF) Roof Cost #
Installing a spray foam roof typically costs $1.50 - $3.00 per square foot for materials, plus $1.00 - $2.50 per square foot for professional installation labor. This results in a total installed cost of $2.50 - $5.50 per square foot.
Key factors impacting spray foam roofing costs:
Roof size - Prices are lower per square foot for larger roofs.
Roof type - Coating existing roofs costs less than new construction.
Foam thickness - 1" to 3" is common. Thicker foam costs more.
Type of foam - Closed cell foams cost more than open cell.
Accessibility - Multi-story and difficult access adds labor costs.
Surface coatings - Extra coatings like silicone, acrylic or urethane add cost.
Location - Labor rates vary across different regions.
For a typical 2500 sq ft roof, expect total installed costs of $6,250 - $13,750 for a spray foam roof.
Real Life Spray Foam Roofing Example Costs #
I had a contractor install 2" of closed cell spray foam on my flat commercial roof here in Ohio. For the 10,000 sq ft roof, the foam itself cost $2 per sq ft and the installation added $1.50 per sq ft. My total cost was $35,000.
I had open cell foam sprayed on my residential roof in Florida to seal it from leaks. They used 1.5" of foam at $1 per sq ft and install was $0.75 per sq ft. For my 1500 sq ft roof the total price was $2,625.
I upgraded my home's old roof in Colorado by having 1" of closed cell foam sprayed on top of the shingles, then coated. The foam was $1.75 per sq ft and install was $1 per sq ft, so my total 2500 sq ft roof cost $6,875.
I had 2.5" of foam sprayed on my commercial flat roof in New York. The closed cell foam cost $3 per sq ft and pro install was $2.25 per sq ft. My total for 20,000 sq ft was $100,000.
As you can see, prices can range from $1.75 - $5.50 per square foot based on specific factors like foam thickness, roof type, accessibility, and location. Always get quotes.
The Benefits of a Spray Foam Roof #
The chemical properties of polyurethane make spray on foam roofing an excellent alternative to other flat roofing systems such as built-up roofing (BUR) and single-ply roofs. The many reasons why you should consider roof foam for your next roofing project include the following:
- Low Lifecycle Cost: In addition to having a low installation cost, SPF roofing, according to studies performed by Structural Research Inc., offers the lowest lifecycle cost. For the 20 or 30 years that a foam roofing system is expected to last, you can count on it requiring little or no maintenance.
- Seamless Leak Protection: Because it is applied as a liquid, a foam roof creates a single, monolithic (seamless) membrane over the entirety of the substrate. With no seams or joints for water to penetrate, two of the most common sources of leaks are eliminated.
- Protection: Despite being extremely lightweight, foam roofing systems provides some of the best weather protection in the industry, including excellent thermal insulation, wind uplift resistance, hail resistance, and, as mentioned above, water impermeability.
- Sustainability: When properly installed and recoated every 5 to 10 years, it's possible for foam roofing to last 40 years or more. In some cases, it can even last for the lifetime of the building. Eliminating the need for roof replacement, you save not only money, but also landfill space. Waste is also reduced with the application of SPF roofing because it is applied directly over the existing roof material.
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