Cost of Spray Foam Insulation

Spray foam insulation comes in two types: i) open-cell spray and ii) closed-cell spray. The cost of open-cell spray foam is around $0.44 to $0.65 per board foot. Close-cell spray price ranges from  $1 to $1.50 per board foot. On average homeowners spend about $2,400 to have their walls sprayed by a professional. Spray foam insulation is a very good alternative to fiberglass insulation during construction or when building a roof as it can be used to fill in any cavities.

spray for insulation cost

Foam Insulation Costs

Foam Insulation Costs

Average Cost$2,360
Typical Range$1,270 and $3,643

Spray-In Insulation Costs by Type

The cost of spray foam insulation installed is higher than the material itself. A foam insulation project requires hiring a contractor to handle all the actual work and also setup, preparation, trash removal, and cleanup.

The cost of spray foam insulation per square foot depends on the foam type and the thickness of the insulation. The thicker the foam the more time it takes to spray. Professionals charge either per square foot or provide a fixed cost. 

Foam type Materials per board foot Installation per square foot
Open-cell $0.44-$0.65  $1.50-$4.90  
Closed-cell $1-$1.50 $1.50-$4.90

Spray Foam Insulation Cost Per Square Foot

The cost of spray foam insulation starts from $0.44 per board foot and can reach $1.50. Expanding your foam insulation can cost from $0.50 to $2.50 per square foot. Contractors find it more convenient to provide estimates for the cost of foam insulation in board feet as it is easier to calculate. A board foot is the volume of a one-foot length of a board one foot wide and one inch thick.

Size in Square Feet Price*
100 $45-$150
200 $90-$300
300 $135-$450
400 $180-$600
500 $220-$750
1,000 $440-$1,500
1,500 $660-$2,250
2,000 $880-$3,000
2,500 $1,100-$3,750
3,000 $1,320-$4,500

*For the costs provided above we assume that the foam thickness is one-inch. Use the calculator above to estimate the cost for more inches by multiplying the number of inches by the cost. 

Where to Use Spray Foam Insulation

Spray foam is a very versatile product that can be used in many places in the home for insulating and filling the gaps in walls, crevices, and around windows and doors.

  • Dull the noise of water pipes by placing a small amount of spray insulation foam between pipes and framing.
  • Insulate and fill the gaps in walls, crevices, and around windows and doors.  
  • Shore up your bathtub by filling the space underneath with spray foam.
  • Keep pests away by filling in any cracks in your home with copper mesh.
  • Prevent mold from growing on the corners of exterior walls.
  • Improve your aluminum sink by Insulating and soundproofing it with spray foam.

Expanding Foam for Basement Walls Price

Installing expanding foam in the basement wall costs on average around $2,150 for a 1,000 square feet space before labor. Spray foam insulation in the basement helps prevent mold. 

Polyurethane Foam Insulation in Crawl Spaces

The cost of adding polyurethane foam insulation in a crawl space below the house comes to about $80 for materials only.  For areas measuring more than 2×10, the cost will be will higher.

Spray Roof Insulation

Spray roof insulation costs on average $1,650 before labor. Spray foam is an excellent solution for insulating roofs. Most roofing contractors proffer the closed-cell foam as it is more effective. If you intended to spay yourself, ask a contactor first which one works best.

Rim Joists 

The average cost to insulate a rim joist with spray foam is between $1,200 and $1,500. Spray foam makes a great choice for insulating rims and sealing cracks. The price for this project depends on the number of rim joists that need to be insulated. However, the cost is less for larger insulating projects like attic or basement insulation. 


Garage spay foam insulation costs on average between $330 and $1,150. You can reduce the cost if you choose not to have the door insulated with spray foam material.

Pole Barns or Other Detached Outbuilding

Pole barn foam insulation costs on average from $740 to $2,500. The price is based on a 30×40 foot pole barn with 12-foot ceilings. Spray foam can improve the R-value insulation in metal buildings.

Difference in Cost Between New And Old Homes

Old homes cost more to insulate with foam than new ones. The cost of foam insulation increases in old houses because installation companies have to work on the existing insulation and structures rather than designing new insulation to improve heat transfer, soundproofing, and cut down utility bills.

Installers usually spray a thin layer of foam to seal leaks and then use a less expensive insulation. If you own an old house consider hiring an energy auditor or performing weatherization instead of installing foam insulation. 

Spray Foam Insulation Prices by Location

Location Average Cost
Minneapolis, Minnesota $1,870
Atlanta, Georgia $3,410
Chicago, Illinois $1,780
Houston, Texas $2,501
Trenton, New Jersey $2,980
Phoenix, Arizona $2,240
Austin, Texas $2,840
Los Angeles, California $1,700
New York, New York $2,560
Denver, Colorado $2,340
Portland, Oregon $2,440
Philadelphia, Pennsylvania $1,900

Polyurethane Foam Installation Cost Factors

Polyurethane foam installation cost depends mostly on the i) thickness ii) type of foam. Other factors that affect the overall project cost are the age of the house and the debris disposal. Estimate about $0.44 to $0.65 if you choose an open cell product per board foot and roughly $1.00 to $1.50 per board foot if you select a closed-cell insulation product. 

Injection Foam Insulation Costs by Thickness

Foam thickness (inches) Cost per square foot
1” $0.44-$1.50
2” $0.88-$3.00
3” $1.32-$4.50 
4” $1.76-$6.00

How Much Spray Foam Insulation Do You Need?

The amount of spray foam insulation required is different for every home and depends mostly on the weather conditions. In climates with extreme weather fluctuations, it is important to have a thick spay layer applied to increase the R-Value. 

Calculating How Much Foam You Need

  1. Take Measurements for each wall to be filled (Length x Height)
  2. Subtract the square feet of doors and windows in that wall.
  3. Subtract 6% for the frames.
  4. Take that total and multiply by the spray foam thickness.
  5. The result will show you how many board feet of spray foam you need.

Types of Spray Foam Insulation

There are two types of polyurethane spray foam used in construction for insulation:ght-density open-cell spray foam insulation and medium-density closed-cell spray foam. Both types are the thermoset cellular plastics. Consult a contractor before making any decision to help you make the right decision.

Open-Cell vs. Closed-Cell Foam Insulation

Open-cell spray foam(or half-pound foam) is ideal for holes and cracks indoors. Closed-cell spray foam (or two-pound foam) is better to be used for exposed external walls to insulate and protect the wall from extreme weather conditions. 

Open-Cell Closed-Cell
R-Value is 3.5-3.6 per inch R-value is 6-6.5 per inch
Less dense Denser
Lower price Higher price
Very expandable Expands very little
Weak moisture barrier Strong moisture barrier
Ideal for soundproofing Very solid
Does not have a vapor retarder Contains a vapor retarder
Not good for roof decking Ideal for roof sheathing

R-Value and Thermal Resistance

Foam Type Thickness R-Value
Open-cell 1” 3.7
Closed-cell 1” 6.5
Open-cell 2” 7.4
Closed-cell 2” 13.0

The R-Value is used as a measure of how heat-resistant a material is. The higher the R-Value the more thermal resistance the material has. All insulation products are assigned to an R-value which is placed on the package in a conspicuous way. This is an important measure for an insulation project so keep it in mind.  Heat gain and loss can happen in many ways. Below you can see the most important ones:

Polyurethane spray foam is great for preventing heat loss and has can satisfy all the above-mentioned criteria. If you are not sure about which spray foam insulation to install check out the Energy Star map for the United States. 

Pros & Cons of Foam Insulation

Advantages of Foam Insulation

  • Reduces energy bills. 
  • It is 50% more effective. 
  • Moist resistant.
  • Prevents the growth of mildew.
  • Good for noise insulation.


  • Higher cost of upfront installation.
  • Takes longer to install than traditional products.
  • Contractors might miss several spots.
  • A contractor might agree to do the job and then pull away.
  • Might cause eye, skin, gastrointestinal or respiratory irritation*
  • Often associated with hypersensitivity pneumonitis.

The side effects are not that common today as the majority of the manufacturers have addressed any health issues associated with isocyanates. Seek advice from your insulation contractor.

DIY vs. Hiring Professional Spray Foam Insulation Contractors

Hiring a contractor to do handle the spray foam insulation project will drastically reduce the time and stress to do the job yourself. Professional installers have experience and all the tools to complete the job without stressing out. Below you can see the pros and cons of hiring a contractor. 


  • Any size project. Contractors can handle any size of insulation projects.
  • Insulating existing walls. Existing enclosed walls require great skills to avoid tearing down the drywall. 
  • Less time: When hiring a contractor you cut down drastically the time that it takes to complete the job.
  • Stress-free. Leave all worries to professionals and avoid worrying about the final outcome. 
  • Disposal of old insulation. An experienced contractor will also remove and dispose of the old insulation from any area in the house (attic, crawl space, and rim joist).
  • Knowledge of building codes. Quality insulation contractors have good knowledge of the latest building codes, energy efficiency codes, and rebates.
  • Expert advice: If you are interested in reducing your energy bills and making your home more energy-efficient, an experienced insulation contractor can always provide useful advice. 
  • Structural Issues: Insulation contractors will easily be able to tell you if your house has any structural issues and how to deal with moisture and mold.


  • Higher cost. Hiring a contractor costs more than a DIY project, so if you do not have the budget it might not be an option. 
  • Find the right contractor: Find someone experienced that you can trust for the job sometimes takes time. You need to do your own research, get estimates and ask neighbors and friends. 
  • Waiting for installation. You may have to wait several weeks in some cases to get on the contractor’s installation schedule.


How much does it cost to insulate a 1500 sq ft house?

On average it costs between $1,500 to $2,000 to hire a professional to insulate a 1500 square feet house.

Can you do spray foam insulation yourself?

Many homeowners think that by buying a do-it-yourself spray foam insulation kit for their house will save them a lot of money. However, fire officials and insulation contractors recommend DIY only for small jobs. In addition, spray foam needs to be handled with care because it is made of chemicals and might damage your health if you are not careful. 

Is spray foam insulation worth the money?

The initial spray foam insulation is a very good investment that could reduce your energy bills by 20% if the house is insulated properly and all air leaks are sealed. In the long term, you will get a very good return on investment and make all the funds that you invested in the first place.

What is the R-value of 1 inch of spray foam insulation

The R-Value of one-inch open-cell spray foam is R-3.5. The R-Value of one-inch closed-cell foam spray is R-6.5

What is the R-value of 2 inches of spray foam?

The R-Value of 2 inches spray foam is R13. The R-value of open-cell spray foam for one-inch is R-3.5 and for closed-cell foam R-3.6 per inch.

What is the R-value of 3.5 inches of spray foam?

Depending on the brand the R-Value of 3.5 inches spray foam can range from R12.5 – R 24.5.

Can mold grow on spray foam insulation?

Spray foam insulation does not attract mold and can help control indoor humidity. Polyurethane spray foam insulation is the only product that can prevent moisture to accumulate in areas like the attic that can then provide mold the right environment to grow and spread out.

Can spray foam rot your roof?

No, spray foam will not rot your roof, even though you have installed open-cell spray foam insulation at the bottom of their OSB (Oriented Strand Board) roof decking.

How long does spray form insulation last?

According to the Association of Certified Home Inspectors, spray foam insulation can last for more than 80 years.

Can you leave spray foam insulation exposed?

It is advisable to leave spay foam insulation exposed only indoors and not in living areas. If you leave spray foam exposes to sunlight it will deteriorate in a year or so.

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