How Much Does Foam Board Insulation Installation Cost in 2022?

Typical Range:

$4,000 - $9,000

Find out how much your project will cost.

Cost data is based on research by HomeAdvisor.

Updated January 23, 2023

Written by HomeAdvisor.

Foam board insulation cost ranges between $4,000 and $9,000, with an average cost of $6,500. Foam board insulation materials cost between $2,000 and $8,000. Prices can vary on the R-value of the insulation, the hours it takes to install, and additional materials like drywall.

Average Cost to Install Rigid Foam Insulation

Average Cost High Cost Low Cost
$6,500 $9,000 $4,000
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What Is Rigid Foam Insulation?

Rigid foam insulation is board insulation with varying thermal resistance values, or R-values, which measure the resistance level to heat flow for a given material. You install rigid foam insulation primarily on exterior walls and basements and include the following:

  • Polyisocyanurate (polyiso)

  • Expanded polystyrene (EPS), also known as beadboard

  • Extruded polystyrene (XPS)

  • Graphite polystyrene (GPS)

  • Structural insulated panel (SIP)

Rigid foam insulation gets scored and broken off to fit areas. When installed on the interior, the rigid foam must be covered with a 1/2-inch gypsum board (drywall) or other building code-approved material for safety. When installed on the exterior, the rigid foam must be covered with weatherproof facing.

Rigid Foam Insulation Prices

Rigid foam boards cost between $0.60 and $2 per square foot, with an average cost of $1.50 per square foot. Rigid foam insulation boards typically come 8 feet high by 4 feet wide and cover 32 square feet. Prices will vary with the R-value of the boards. Rigid foam boards with higher R-values will cost more than those with lower R-values.

Rigid Foam Insulation Installation Costs

A local insulation contractor will charge between $50 and $150 per hour to remove and dispose of old insulation and install new rigid foam board insulation. Installing rigid foam insulation can cost $0.50 to $1.50 per square foot. Prices will rise if you need to install drywall, have unique dimensions, or require additional material. 

Rigid Foam Board Cost by Room Size

Rigid foam insulation can cost between $550 and $1,750 for a 500-square-foot space, slightly larger than a typical garage. For bigger projects, like a whole house, rigid foam insulation costs range between $1,650 and $5,250 for a 1,500-square-foot area. The type of insulation, its R-value, labor, and material costs will influence the final total.

Sq. Ft. Average Cost Range (All-In)
500 $550 – $1,750
750 $830 – $2,630
1,000 $1,100 – $4,500
1,200 $1,320 – $4,750
1,500 $1,650 – $5,250
Number of foam insulation boards needed per square footage, with 1,000 square feet averaging 35 boards
Photo: Roman Mykhalchuk / iStock / Getty Images Plus / Getty Images

How Much Does Rigid Foam Board Cost by Area in Home?

The cost of rigid foam insulation will vary by the room and area in a home based on code requirements, personal preference, and space size. Recommended and required R-values can vary across municipalities based on U.S. climate zones as well. Different spaces may require more custom fitting of foam boards. 

Home Space Average Cost Range (All-In)
Crawl space $550 – $5,250
Garage $550 – $12,000
Basement $1,100 – $5,250
Attic $1,650 – $7,000
Wall $1,650 – $7,000
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How Much Is Foam Board by Foam Type? 

There are five main types of rigid foam insulation, and each type can have different costs based on the thickness and R-value. Rigid foam boards come as 8-foot by 4-foot boards with varying thicknesses up to 2 inches. Rigid foam insulation can compare to traditional batt and roll insulation costs.

You can install polyiso, expanded polystyrene, extruded polystyrene, and graphite polystyrene on existing and new structures. On the other hand, you typically install structural insulated panels with new construction projects.

Rigid Foam Type Average Cost per Sq. Ft.
Polyiso $0.65 – $0.85
Expanded polystyrene $0.40 – $0.75
Extruded polystyrene $0.60 – $1.50
Graphite polystyrene $2
Structural insulated panels $9.50 – $12


Polyisocyanurate, or polyiso insulation, costs between $0.65 and $0.85 per square foot. Polyiso comes in 8-foot by 4-foot boards and can have an R-value of 6. It has a reputation for degraded insulating value when temperatures dip below 50 degrees Fahrenheit. Polyiso is a closed-cell insulation and is considered the densest. 

Expanded Polystyrene (EPS)

Expanded polystyrene can cost between $0.40 and $0.75 per square foot. EPS is a closed-cell insulation, meaning it’s better for insulating. EPS typically contains 98% trapped air and works well for exterior walls. It can come as contoured boards, which can help insulation and impact-resistance for siding. 

Extruded Polystyrene (XPS)

Extruded polystyrene (XPS) insulation costs between $0.60 and $1.50 per square foot. XPS is a closed-cell insulation and is considered stiffer than EPS and polyiso. XPS can work well for roofs and below-grade slab areas.

Graphite Polystyrene (GPS)

Graphite polystyrene foam insulation costs about $2 per square foot. GPS has an increased price because graphite can slow the transfer of heat more than other insulation materials. GPS is a closed cell-insulation and is made similarly to EPS.

Structural Insulated Panel (SIP)

Structural insulated panels cost between $9.50 and $12 per square foot. SIPs come as a complete unit with a rigid foam board sandwiched between two plywood or oriented strand board (OSB) sheets. They’re weight-bearing and can replace traditional stick framing. SIPs mostly get used with new construction.

Pros and Cons of Using Rigid Foam Insulation

Rigid foam board insulation has several advantages because of its versatility, but it also has a few drawbacks. Rigid foam board is easy to work with and works best in basements and exterior walls. In contrast, rigid foam boards don’t work as well for attics because they tend to have lower R-values than other insulation options.

Rigid foam pros:

  • Easy to install

  • Moderately priced

  • Moisture-resistant

Rigid foam cons:

  • Lower R-values than other insulation materials

  • May require lots of cuts to fit around ducts and pipes

  • Often needs covering with drywall

DIY vs. Hiring an Insulation Pro

Installing rigid foam insulation can be a DIY project with the right know-how. Installing rigid foam insulation on exterior walls and basements requires careful work to avoid potential moisture issues, which local mold inspectors can do best. 

In addition, installing rigid foam insulation can involve making a lot of cuts to boards, which is time-consuming, especially if not done accurately. If you have to insulate a large space with lots of nooks and crannies, you can likely save yourself time and frustration by hiring a pro.

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Is rigid foam insulation good for walls?

Rigid foam board insulation works well for walls, especially basement and exterior walls, because they're moisture-resistant. They can offer adequate insulation, depending on your climate zone. But in colder climates, you might need to stack them. Rigid foam insulation is typically found in basements between the studs or along a concrete wall. Rigid foam insulation also gets used on a home's exterior behind the siding.

Is rigid foam a good insulator?

Yes, rigid foam is a good insulator since it can reduce air infiltration and thermal bridging, which occurs if there's an easier path for hot air to travel. Rigid foam also can have a higher R-value than conventional fiberglass batt insulation and doesn't carry high spray foam insulation costs.

Where should you use each type of rigid foam insulation?

You can use rigid foam insulation in various spaces, but it typically gets installed in basements, crawl spaces, and exterior walls. You can install rigid foam insulation in attics, but when it does, the attic typically gets finished since rigid foam needs drywall installed behind it, raising attic insulation costs. Depending on your climate zone and building codes, you might need to stack boards on rigid foam insulation because the R-value doesn't usually exceed an R-15 level. 

How long will foam board last?

The International Association of Certified Home Inspectors has said foam board insulation can last up to 100 years if properly installed. Some insulation materials can suffer from water damage or start to sag over many years, thus reducing their insulating ability. Foam boards shouldn't suffer from sagging but have the potential to get damaged. Any broken pieces of foam board can reduce its insulating effectiveness.