Written by
Tara Farmer
Edited by
Kristen Cramer
Fact-checked by
Tom Grupa
Spray foam insulation cost
Spray foam insulation costs$1.00 to $4.50 per square foot, depending on the type, R-value, and job size. The average cost of spray foam insulation is$1,300 to $4,000installed. Closed-cell spray foam costs$1.30 to $2.90 per board footand open-cell spray foam costs$0.60 to $1.30 per board foot.
| Location | Average cost installed |
|---|---|
| Existing walls | $3,200 – $8,800 |
| Attic floor | $1,100 – $6,800 |
| Attic rafters / roof deck | $1,500 – $9,000 |
| Basem*nt | $1,500 – $5,600 |
| Garage walls | $2,600 – $8,900 |
| Garage ceiling | $1,500 – $3,000 |
| Crawl space | $1,200 – $6,700 |
| Rim joists | $1,200 – $2,000 |
| Around HVAC | $1,000 – $3,300 |
| Whole house | $4,000 – $26,000 |
| Pole barn | $3,500 – $16,500 |
| Shipping container | $800 – $3,200 |
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Spray foam insulation cost calculator
The following table reflects the average cost to install spray foam insulation.
| National average cost | $2,600 |
| Minimum cost | $600 |
| Maximum cost | $8,000 |
| Average cost range | $1,300 to $4,000 |
*Cost data is from research and project costs reported by HomeGuide members.
Open-cell vs. closed-cell spray foam cost
Closed-cell spray foam costs$1.30 to $2.90 per board footinstalled, while open-cell spray foam insulation costs$0.60 to $1.30 per board foot. A board foot is one square foot with 1" thickness.
| Factor | Open-cell foam | Closed-cell foam |
|---|---|---|
| Material cost (per board ft) | $0.30 – $0.50 | $0.90 – $1.00 |
| Installed cost (per board ft) | $0.60 – $1.30 | $1.30 – $2.90 |
| R-value per inch | 3.5 – 3.7 | 5 – 7 |
| Density (per cubic ft) | 0.5 lbs. | 2 lbs. |
| Expansion | Expands to 3" | Expands to 1" |
| Moisture barrier | Semi-permeable | Impermeable |
| Sound dampening | Good | Better |
| Vapor retardant | Semi-permeable | Impermeable |
| Roof sheathing application | Not recommended | Recommended |
| Best for | Above-grade installations, like wall cavities and attic floors | Below-grade applications, like basem*nts and crawl spaces |
Spray foam insulation cost per square foot
Spray foam insulation costs$1.00 to $4.50 per square footof surface area installed, depending on the project size, location, and whether it is open-cell or closed-cell foam.
Get free estimates from spray foam insulation contractors near you.
| Square feet | Average installed cost |
|---|---|
| 100 | $100 – $450 |
| 200 | $200 – $900 |
| 300 | $300 – $1,400 |
| 400 | $400 – $1,800 |
| 500 | $500 – $2,300 |
| 1,000 | $1,000 – $4,500 |
| 1,500 | $1,500 – $6,800 |
| 2,000 | $2,000 – $9,000 |
| 2,500 | $2,500 – $11,300 |
| 3,000 | $3,000 – $13,500 |
Average cost to spray foam a house
The average cost to spray foam a whole house is$4,000 to $26,000, depending on the home size, number of stories, areas insulated, foam type and thickness, and whether it's new or existing construction.
Spray foam insulation in existing walls cost
Installing spray foam insulation in existing walls costs$3,200 to $8,800on average, depending on the project size. Installers spray slow-rising "injection foam" through holes drilled in the drywall or siding to fill the existing stud cavities.
Closed-cell injection foam adds strength to the walls.
Open-cell injection foam is better for sound dampening.
Attic spray foam insulation cost
Attic spray foam insulation costs$1,100 to $6,800+, depending on the foam type, R-value, and whether insulating the attic floor or the roof deck's underside.
Attic insulation companiesrecommend open-cell foam in vented attics to fill nooks and crannies in the floor, but it may require a vapor barrier in cold climates.
| Location | Average cost installed |
|---|---|
| Attic floor | $1,100 – $6,800 |
| Attic rafters / roof deck | $1,500 – $9,000 |
Roof foam insulation prices
Spray foam insulating a roof deck costs$1,500 to $9,000, depending on the foam type, roof size, and pitch. Roof insulation regulates attic temperature and improves air conditioning efficiency in attics with HVAC equipment and ductwork.
Closed-cell spray polyurethane foam (SPF) is best for roof deck applications in unvented attics.
Basem*nt spray foam insulation cost
Spray foaming basem*nt walls costs$1,500 to $5,600, depending on the foam type and basem*nt size. Open-cell and closed-cell foam provide an air seal, thermal resistance, mold resistance, and longevity.
Open-cell foam is best when finishing the basem*nt walls with drywall.
Closed-cell foam blocks moisture, improves the walls' structural integrity, and is best when leaving the basem*nt walls exposed.
Address any moisture problems before installing insulation. Basem*nt waterproofing costs $4,500 to $15,000 to seal the foundation, waterproof walls with cement, install a sump pump or perimeter drain, and divert downspout runoff away from the foundation.
Cost to spray foam insulate a garage
Insulating a garage door with spray foam costs$200 to $300, while insulating all the garage walls costs$2,600 to $8,900. Closed-cell spray foam is ideal for unfinished garage walls. Open-cell foam is better for a finished garage.
| Location | Average cost installed |
|---|---|
| Garage door | $200 – $300 |
| Garage walls | $2,600 – $8,900 |
| Garage ceiling | $1,500 – $3,000 |
Insulating the garage door with cellulose or rigid foam and air sealing with weatherstripping is typically more effective than spray foam.
Spray foam insulation for crawl space cost
Crawl space spray foam insulation costs$2 to $5 per square footinstalled or$1,200 to $6,700on average, depending on the area size and conditions. Combining closed-cell spray foam and rigid foam board is ideal for insulating a crawl space.
Closed-cell foam is recommended because it has air, moisture, and vapor barrier properties, adds strength to the walls, and provides a tight seal.
Open-cell spray foam is not recommended in below-grade crawl spaces because it allows moisture through.
Cost to spray foam rim joists
Spray foaming the rim joists costs$1,200 to $2,000for labor and materials. Removing drywall to access the joists increases costs. Insulating the rim joists with closed-cell foam reduces baseboard drafts and improves the home's structural integrity.
Consider insulating the joists with rigid foam board and using spray foam to seal the gaps and joints.
"Flash and batt" is a less expensive method that uses a thin closed-cell spray foam layer with a batt insulation layer to seal all joints and achieve the desired R-value.
Spray foam pole barn cost
Installing spray foam in a pole barn costs$3,500 to $16,500, depending on the project size, foam type, and climate zone. Closed-cell spray foam works best for pole barns because it adds structural strength and doubles as a vapor barrier.
Insulate the roof and walls when using the pole barn for storage or recreation.
Insulate only the roof if the pole barn houses livestock.
Injection foam insulation cost
Injection foam insulation costs$2 to $10 per square footinstalled. Injection foam is non-expanding, slow-rise foam used for enclosed wall cavities. Installers inject foam through holes cut in the interior drywall or exterior siding.
Injection foam insulation:
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Comes in closed-cell and open-cell varieties
May require the wall cavity to be free of other insulation
Drywall repair costs $200 to $750and is typically included in the estimate.
Spray foam insulation price factors
The following factors impact the price:
Insulation type – Open-cell foam is cheaper than closed-cell foam but provides less R-value per inch.
Project size impacts the labor and materials required.
New vs. existing home – Adding spray foam insulation is easiest during new construction. Existing homes require more labor to access areas and reseal the spaces created for foam injection.
Siding type – Contractors typically spray foam in existing exterior walls from the outside. Vinyl siding is the easiest to remove and reattach. Brick and wood siding require the most labor.
Labor – Contractors charge $50 to $100 per hour to install spray foam insulation.
Accessibility – Labor costs increase for homes with multiple stories, a tight crawl space, or an attic with hard-to-reach areas and a high-pitched roof.
Geographical location – Colder climates require thicker insulation than warm regions.
Vapor barrier – Open-cell foam installation may require a vapor barrier, depending on local building codes. Closed-cell spray foam doubles as a vapor barrier.
Removing old insulation costs $1 to $2 per square foot.
Minimums – Some insulation companies have a $1,200 to $2,000 or more minimum project charge.
Installing a roof vent costs $200 to $700. Attic ventilation is necessary when spray foaming the attic floor. Installing spray foam at the roof deck does not require venting because the attic is sealed and becomes part of the conditioned home.
Electricians charge $50 to $130 per hourto fix wiring damaged during the insulation process.
Cleaning & hazard removal:
Attic cleaning costs $100 to $600or more, depending on the condition.
Mold removal costs $15 to $30 per square foot.
Asbestos removal costs $10 to $25 per square foot. Asbestos testing costs$250 to $850.
A pest inspection costs $40 to $150 and is recommended before adding insulation.
Spray foam prices by thickness
Spray foam prices increase based on the foam thickness installed:
The recommended thickness for open-cell spray foam is 6" to 10" at the roof deck or ceiling and 3" in wall cavities.
Closed-cell spray foam requires 4" to 5" at the roof deck and 2" to 3" in the walls.
| Foam Thickness (inches) | Open-cell R-value | Open-cell installed cost per SF | Closed-cell R-value | Closed-cell installed cost per SF |
|---|---|---|---|---|
| 1” | 3.5 – 3.7 | – | 5 – 7 | $1.30 – $2.90 |
| 2” | 7.0 – 7.4 | – | 10 – 14 | $2.60 – $5.80 |
| 3” | 10.5 – 11.1 | $1.80 – $3.90 | 15 – 21 | $3.90 – $8.70 |
| 4” | 14.0 – 14.8 | $2.40 – $5.20 | 20 – 28 | $5.20 – $11.60 |
| 5” | 17.5 – 18.5 | $3.00 – $6.50 | 25 – 35 | $6.50 – $14.50 |
| 6” | 21.0 – 22.2 | $3.60 – $7.80 | 30 – 42 | $7.80 – $17.40 |
| 7” | 24.5 – 25.9 | $4.20 – $9.10 | 35 – 49 | $9.10 – $20.30 |
| 8” | 28.0 – 29.6 | $4.80 – $10.40 | 40 – 56 | $10.40 – $23.20 |
| 9” | 31.5 – 33.3 | $5.40 – $11.70 | 45 – 63 | $11.70 – $26.10 |
| 10” | 35.0 – 37.0 | $6.00 – $13.00 | 50 – 70 | $13.00 – $29.00 |
Spray foam brands
Most spray foam brands require a licensed contractor or certified technician to purchase the product. Popular spray foam brands include:
Demilec / Huntsman Building Solutions
Icynene
Johns Manville (JM)
Lapolla Industries
RetroFoam
Walltite / BASF
Spray foam cost vs. fiberglass, batt, and rockwool
Other types of insulation cost $0.80 to $2.80 per square foot, or2 to 3 times less than spray foam. Still, spray foam has a higher R-value per inch and lasts longer than other insulation types when properly installed.
Blown-in insulation costs $1.00 to $2.80 per square footfor fiberglass or cellulose.
Rockwool blown insulation costs $1.90 to $2.40 per square foot.
Fiberglassbatt and roll insulation cost$0.80 to $2.60 per square foot.
DIY spray foam insulation cost
Hiring a pro is best for large projects as spray foam involves mixing dangerous chemicals at specific ratios and temperatures. Safe, proper application requires training and skill. Many companies only sell or warranty spray foam to certified technicians.
Spray foam insulation kit prices
DIY spray foam insulation kits cost$300 to $500to cover 200 square feet with 1" thickness. Spray foam kits work well for patching and insulating around doors and windows. Closed-cell foam kits cost more than open-cell kits.
DIY spray foam insulation kit brands include:
FOAM iT
Foam It Green
FomoFoam
GREAT STUFF (PRO)
Handi-Foam
Tiger Foam
Touch 'n Seal
Touch 'n Foam
Spray foam insulation FAQs
How long does polyurethane foam insulation last?
Most polyurethane foam insulation lasts80 to 100 yearswhen installed correctly. Spray foam insulation on the roof deck's underside lasts about30 years.
Is spray foam insulation worth the cost?
Spray foam insulation is worth the cost and increases energy efficiency, adds structural integrity, air seals gaps, and may save15% to 40%on utility and energy bills.
| Pros | Cons |
|---|---|
|
|
What is the R-value of spray foam insulation?
The R-value of spray foam insulation is3.5 to 7 per inch, depending on the type and manufacturer. R-value is the measure of a material's heat transfer resistance. Higher R-values indicate better insulation.
| Type | R-value per inch |
|---|---|
| Open-cell | 3.5 – 3.7 |
| Closed-cell | 5 – 7 |
Is spray foam insulation safe?
Properly installed spray foam insulation is inert and generally safeaftercuring. Most spray foam is polyurethane, which contains chemicals dangerous to the skin and lungs. Installation requires protective gear. You must vacate the sprayed area for 24 hours or more until cured.
How much does spray foam expand?
Closed-cell spray foam expands to about1" thick. Open-cell foam expands to3" thick. Low-expansion spray foam expands20 to 30 timesits liquid size, while high-expansion foam expands200 to 300 timesits liquid size.
Getting spray foam insulation estimates and quotes
Before hiringinsulation contractors:
Get at least three quotes to compare.
Ask for a detailed quote including areas to be sprayed, estimated R-value, insulation depth or thickness, and spray foam brand and type.
Ask for a foam removal guarantee in the event of incorrect installation.
Look for certified spray foam insulation professionals.
Read their reviews on HomeGuide and Google.
Select insured and bonded companies that have been in business for 5+ years.
Ask for references.
Avoid selecting the lowest quote as quality may suffer.
Get a detailed estimate, contract, and warranty in writing before the work begins.
Never pay in full before the project starts. Use a payment plan instead for work completed.
Questions to ask spray foam installers
Are you licensed, bonded, and insured?
How long have you been in business?
What experience do you have with spray foam insulation?
Will the work be subcontracted?
Is spray foam the best insulation type for my space?
Do you recommend open-cell or closed-cell insulation for my space, and why?
Is removing damaged or old insulation included in the quote?
What additional costs should I expect?
How long does it take to cure, and when can we safely re-enter the house?
Do you use a machine that automatically shuts off if the spray foam formula ratios are incorrect?
How long will the project take?
How long should the insulation last?
Is there a warranty, and if so, what does it include?
Do you offer a whole-house discount?
Do you offer financing options?
Are there rebates available, and do you apply for them?
