How Much Does Spray Foam Insulation Cost? (2024) (2024)

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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.

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.

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.

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.

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.

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.

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.

• Blown-in cellulose: Made of paper but treated to be fire-retardant, cellulose is eco-friendly and produces neither irritating dust nor VOC off-gassing. The downside is this insulation’s weight and moisture-holding tendencies.
• Blown-in fiberglass: This type of loose-fill fiberglass insulation can conform better than batting to tight spaces, and it’s good for retrofitting existing homes. However, fiberglass dust can irritate the lungs, and loose insulation can hold onto moisture.
• Fiberglass batts: The least expensive form of modern insulation, fiberglass batting is very quick and easy to install. Compared to spray foam, it’s difficult to fit around pipes and joists and has a much lower R-value, so you won’t save as much on energy bills.
• Rock wool: Rock or mineral wool is available as batting and rigid boards. It’s inexpensive and more effective than fiberglass batts, but it can contain formaldehyde. It’s also not quite as versatile as blown-in or spray foam insulation.
• Spray foam insulation: Both types of spray foam offer superior R-values for the best insulation performance. Unlike traditional insulation, spray foam acts as a sealant to keep out air leaks. Closed-cell foam can also keep out water leaks. It’s incredibly versatile, since it can be used in open spaces as well as tight crevices. Although it costs the most up-front, it also produces the best energy savings over time.

How to Reduce Spray Foam Insulation Costs

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

• Opt for open-cell spray foam insulation in low-moisture areas.
• If multiple subcontractors are needed, act as your own general contractor for the project to save on labor.
• Homeowners who use spray foam insulation may qualify for the federal energy efficiency home improvement tax credit, which provides a tax credit equal to 30% of the project cost up to $1,200.
• Check for other state and local rebates.

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.

• Installing spray foam requires specialty training, so make sure that your chosen contractor has experience with it.
• Anyone who does work in your home should be bonded and insured.
• Check the company’s Better Business Bureau page for ratings, accreditation status, and customer reviews.
• Ask the contractor for references from satisfied customers.
• Get quotes from at least three local contractors before making your choice.

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.