How Much Does Spray Foam Insulation Cost? (2024)

By Tamara Jude Updated April 11, 2024

Typical costs range from $2,400 to $8,600.

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Spray foam insulation costs typically range from $2,400 to $8,600, but homeowners will pay $5,500 on average for a single room, such as a basement or garage. You can expect to pay between $2.75 to $7.50 per square foot for spray foam insulation. Insulation is vital to your home’s energy efficiency. If heat transfers too easily through your walls, floors, and ceilings, your HVAC system must work harder to keep your home at a comfortable temperature, driving up energy bills. Spray foam insulation is a high-performance insulation that can also provide a moisture barrier and soundproofing.

We’ll break down the main factors that impact this price and explain whether installing spray-foam insulation is a do-it-yourself (DIY) project.

Note: The cost data in the article was sourced from Angi and Fixr.


 

Spray Foam Insulation Major Cost Factors

Where your insulation project falls in the above cost range depends on the project’s scope, but the thickness, type of insulation, and location are also factors.

Type of Spray Foam Insulation

Spray foam insulation is a combination of chemicals that expands when it hits air. There are two types of spray foam insulation: open-cell and closed-cell. Open-cell spray foam insulation expands more, so it spreads more easily into tight crevices and costs less. However, the open structure is more easily penetrated by water and air, making it a less effective insulator.

When you need to create a moisture-tight seal, closed-cell spray foam insulation is the better product. It costs more, but it won’t develop mold or mildew even in high-moisture conditions, making it a good choice for bathrooms, basements, and crawl spaces.

Cost by Type of Spray Foam Insulation

Here’s how these two compare on material costs per board foot, which is the amount of insulation needed to cover a 1-square-foot area with a thickness of 1 inch.

Type of InsulationMaterial Cost per Board Foot

Open-cell

$0.44–$0.65

Closed-cell

$1–$1.50

Thickness

Insulation needs to be several inches thick to do its job. Thicker insulation has a high R-value, which measures how well a material keeps heat from passing through. Closed-cell spray foam has a higher R-value (6 to 7) than open-cell insulation (3.5 to 3.6), so you won’t need as much of it. Recommended insulation levels depend on your local climate and where the insulation is needed. Rarely will you need more than 10 inches of open-cell or 7 inches of closed-cell insulation. After a certain point, the R-value levels off, and air sealing becomes most effective for insulation.

Cost by Thickness

Here’s how insulation materials’ cost increases by thickness.

Insulation Thickness in InchesOpen-Cell R-ValueOpen Cell Cost per Square FootClosed-Cell R-ValueClosed-Cell Cost per Square Foot

1

3.5

$0.44–$0.65

6.5

$1–$1.50

2

7

$0.88–$1.30

13

$2–$3

3

10.5

$1.32–$1.95

19.5

$3–$4.50

4

14

$1.76–$2.60

26

$4–$6

5

17.5

$2.20–$3.25

32.5

$5–$7.50

6

21

$2.64–$3.90

39

$6–$9

7

24.5

$3.08–$4.55

45.5

$7–$10.50

8

28

$3.52–$5.20

52

$8–$12

9

31.5

$3.96–$5.85

58.5

$9–$13.50

10

35

$4.40–$6.50

65

$10–$15

Size of Project

The larger the coverage area, the more spray foam insulation is needed and the higher the material and installation costs. This is calculated by the insulation’s square footage, not the room’s floor area.

Cost by Size of Project

The following costs apply to an insulation R-value of 32. That’s about 9 inches of open-cell spray foam and about 5 inches of closed-cell spray foam per square foot.

Square FootageOpen-Cell CostClosed-Cell Cost

100

$39.60–$58.50

$50–$75

200

$792–$1,170

$1,000–$1,500

300

$1,188–$1,755

$1,500–$2,250

500

$1,980–$2,925

$2,000–$3,750

Location in Home

Larger areas in your home cost more to insulate than smaller areas, but different parts of your house also require different thicknesses and types of insulation. As previously mentioned, closed-cell spray foam is necessary in areas that require a moisture barrier. Insulation in wall cavities is typically thinner than in floors, ceilings, and attics. Finished spaces also cost more to insulate because contractors may need to remove flooring and drywall to access the cavities.

Cost by Location in Home

Here’s how the cost of insulating various rooms compares.

Location in HomeCost Range

Crawl space

$1,000–$5,900

Roof

$2,400–$8,000

Basement

$2,400–$8,400

HVAC system

$2,500–$3,000

Attic

$2,500–$12,000

Garage

$3,600–$8,600

Whole-home

$8,000–$30,000

Labor Costs

An insulation contractor usually charges $50 to $100 per hour to apply spray foam insulation, so the total labor cost depends on the job’s size and complexity. A small basement or crawl space can often be insulated in two to three hours, but an entire home will require several days.

Compare Quotes from Insulation Specialists
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Professional vs. DIY Spray Foam Insulation

Though spray foam insulation installation looks easy, it’s actually a fairly complex job.

Professional Spray Foam Insulation

Hiring an insulation contractor to apply spray foam is usually the best choice. The insulation expands very quickly once the chemicals are mixed, and professionals will know how to apply it in even layers to prevent sagging or swelling. Additionally, some insulation manufacturers will only sell their products to licensed professionals. Although you’ll have to pay for labor, professional contractors can complete the job more quickly and neatly than the average homeowner, and they’ll ensure their work meets necessary building codes.

DIY Spray Foam Insulation

There are DIY spray foam insulation kits, but they usually only include the foam and the machinery for spraying. You can get a 200-square-foot kit for about $400 and a 600-square-foot kit for about $800. Because polyurethane foam can be messy and gives off volatile organic compounds (VOCs) as it dries, you’ll also need protective gear for yourself and plastic sheeting to protect your belongings at an additional cost of about $178. This doesn’t include the materials you’ll need to cut into and repair your walls, floors, and ceilings. In general, we recommend leaving this job to the professionals.

 


 

Additional Factors Affecting Spray Foam Insulation Cost

You may have to consider the following additional costs, depending on your project’s specifics.

New Construction vs. Existing Home

A new home that’s still under construction is much easier and less expensive to insulate because all of the cavities are still accessible. In existing homes, contractors may need to first remove existing insulation, particularly if it’s in bad shape from water damage or pest infestation. Here’s how the total costs of materials plus labor compare.

Type of InstallationCost per Square Foot

New construction

$2.75–$6.50

Existing home

$3.15–$7.50

Mold Removal

If water has gotten into insulation cavities, simply removing the old insulation may not be enough. Mold remediation is usually required to remove all affected construction materials and protect the inhabitants of your home from spores and other allergens. This usually costs $1,500 to $3,500.

Vapor Barrier Installation

In extremely humid climates or in areas with a great deal of precipitation, even closed-cell insulation might not be enough to keep water out. In these circumstances, homeowners may need to add a vapor barrier to insulated spaces for an additional cost of $0.65 to $1.00 per square foot.

 


 

Benefits of Spray Foam Insulation

Spray foam isn’t your only option for insulating your floors, ceilings, and exterior walls. Traditional insulation is usually less expensive than spray foam, but it tends to be less effective. Here’s how other types of insulation stack up against spray foam.

Insulation MaterialR-ValueCost per Square Foot

Fiberglass batting

2.9–3.8

$0.64–$1.19

Rock wool

3.0–3.3

$0.65–$2.50

Blown-in fiberglass

3.1–3.7

$1–$1.50

Blown-in cellulose

3.1–3.7

$1–$1.50

Spray foam

3.5–7.0

$2.75–$7.50

 


 

How to Reduce Spray Foam Insulation Costs

Here are some tips to save on spray foam insulation, even if you hire a pro.

 


 

Extra Spray Foam Insulation Options

Many homeowners use spray foam insulation as a way to increase their home’s energy efficiency and comfort. Since this is a fairly disruptive project, it’s often a good idea to bundle it with other, similar projects. Here are some ideas.

Window Replacement

If you’re opening up your walls to spray in foam insulation, you can replace your windows at the same time. Energy-efficient windows also go a long way toward reducing energy costs, and installing new construction windows creates the most weatherproof seal. This is only possible by stripping the rough window opening down to the studs, so it’s a good project to combine with new insulation.

Roof Replacement

If your attic or roof needs new insulation, consider the roof’s age. Paying for a new roof may be worth it if your asphalt shingles are more than 20 years old. You can replace the insulation when the outer roofing materials have been removed, reducing labor costs for insulation contractors.

 


 

How to Hire a Professional

Here’s what to look for when comparing insulation contractors.

 


 

Our Recommendation

Spray foam is a highly effective form of home insulation that can reduce your carbon footprint along with your energy bills. It costs more than other types of insulation, but it will last longer—up to 80 years. Installing any type of insulation is easiest during new home construction, but retrofitting insulation is also possible with a little more time and money.

Compare Quotes from Insulation Specialists
Just answer a few questions, and we’ll take care of the rest!

 


 

Spray Foam Insulation Cost FAQ

Is spray foam worth the money?

Spray foam insulation is so effective at raising your home’s energy efficiency that most homeowners who install it find that it’s well worth the price.

Is there a downside to spray foam insulation?

The main downside of spray foam insulation is that it’s substantially more expensive than other types of insulation. Additionally, because closed-cell spray foam is watertight, it can potentially conceal a roof leak until the damage is severe.

When should you not use spray foam insulation?

Spray foam shouldn’t be used around people without respirators, since it can cause lung, skin, or eye problems for about 24 to 72 hours after installation. The home’s residents will need to stay elsewhere during that time.

How does spray foam insulation help with energy efficiency?

Spray foam insulation acts as an air seal, preventing drafts and air leaks that can force your HVAC system to work harder. It also helps keep heat either in or out of your home depending on the outside temperature.

How does spray foam work?

Spray foam is created when two liquids—isocyanate and polyol resin—are combined. The chemical reaction causes the resulting liquid to expand to fill the available space.