How Much Does Spray Foam Insulation Cost in 2025?

Spray Foam Insulation Cost Factors

The cost of Polyurethane foam installation varies depending on several factors, including the thickness and type of foam, the project’s square footage, debris disposal, and the age of the home. Here’s a quick breakdown of different cost factors.

Thickness

Here's how much spray foam typically costs by thickness per square foot.

Open-Cell Foam vs. Closed-Cell Foam

To understand closed- and open-cell foam, we need to define R-value. The science behind R-values is a bit complicated, but it essentially is a number used to measure how well a layer (such as insulation) resists heat conducting through it. A higher R-value means the layer is more resistant to heat transfer, meaning it will insulate better than something with a lower R-value.

Open-cell foam has a slightly lower R-value than closed-cell foam, but it could save you money on your spray foam insulation project.

Labor

Labor adds between $0.44 and $3.20 per square foot to your overall costs for spray foam insulation. However, other factors could drive the labor costs even higher, including the thickness of the spray foam, installation location, and additional services like setup, preparation, trash removal, and cleanup removal. 

Type

Polyurethane is the most common type of spray foam used by contractors and is also the least expensive at $0.44 to $1.50 per board foot. However, less toxic foams like soybean oil and water-based options have entered the market in recent years. You will pay extra for these options, though. Soybean oil spray foam costs about $1.15 and $2.50 per board foot, water-based spray foam costs $0.50 to $2.50 per board foot, and vegetable oil insulation costs $1.50 to $3 per board foot.

Mold Remediation

Spray foam can kill mold but isn't something you can apply over a moldy section wall section. If you need to remove mold before adding insulation, keep in mind that the cost of professional mold remediation is $1,500 to $3,500. 

New vs. Existing Home

Installing foam insulation in a new home costs much less than doing the same in an older home. New homes are easier because installation companies can design the insulation for optimum soundproofing, heat transfer, and utility costs and can apply the spray foam, while the walls, crawl spaces, and roof deck are easily accessible. 

When working in older homes, pros need to work around existing insulation, drywall, and structures, which costs more in time and money. For example, if homeowners need to repair drywall in addition to adding spray foam insulation, they’ll need to budget between $300 to $920 to cover the cost to repair drywall. Instead, perform weatherization or hire an energy auditor to help pinpoint exactly where you need to add to your insulation.

Spray Foam Costs by Application Location

Where you install spray foam in your home could impact the cost. Learn more below.

Attic

The cost to insulate an attic with spray foam is between $2,500 and $12,000. Contact an attic insulation contractor to see if you can add insulation to the ceiling and the walls for extra protection.

Basement Walls

Installing expanding foam in the walls of a 1,000-square-foot basement costs between $2,400 and $8,400, including labor. Spray foam basement insulation helps prevent mold.

Crawl Spaces

Adding polyurethane foam insulation under a house or in a crawl space costs about $1,000 to $5,900, including labor. Areas larger than 2-by-10 feet will cost more.

Roof 

The average cost to insulate a roof with spray foam is about $2,400 to $8,000, including labor. Closed-cell insulation works best on most roofs. Ask a roofing pro to see which material is ideal for your space.

Rim Joists

Spray foam is an ideal choice to insulate rim joists and seal cracks, and it typically costs between $2,000 to $2,300, including labor and materials. Rim joists, also called band joists, secure the ends of floor joists. The price of this project varies depending on how many rim joists are in your home, although it will cost much less than large projects like insulating an attic or basement.

Garages

Garage insulation costs between $3,600 and $8,600, including installation. If you insulate your garage walls, it’s important to insulate your garage door as well, including weatherstripping the bottom edge of the garage door and installing polystyrene panels on the backside of the garage door.

Pole Barns or Other Detached Outbuildings

The cost to spray foam a pole barn is $8,000 to $25,000 for a new building and $10,000 to $30,000 for an existing building. The price is higher than other application locations due to the increased square footage and material costs. Spray foam insulation on a metal building can improve R-value.

Spray Foam Costs vs. Fiberglass, Batt, & Cellulose

Let’s compare the costs and features of spray foam insulation with other types of insulation.

Spray Foam:

• $2,884 on average

• R-value of 6–7 per inch (closed-cell) and 3.5–3.6 per inch (open-cell)

• Highest R-value insulator

• Provides air sealing in addition to insulation

Blown-In Insulation:

• $1,650 on average

• R-value of 3.1–3.7 per inch

• Some products offer recycled content

Fiberglass Batts:

• $300 to $1,500 on average to install

• R-value of 2.9–3.8 per inch

• Quick to install 

• Improves energy efficiency by up to 30%

Rock Wool:

• $1,900 to $4,200 on average to install

• R-value of 3.0–3.3 per inch

• Offers fire resistance and sound deadening

• Quick to install and an easy DIY project

Pros & Cons of Foam Insulation

Here are some advantages and disadvantages to consider before installing spray foam insulation in your home.

Advantages

• Helps lower utility costs

• Insulates 50% better than traditional products

• Protects and reinforces your drywall 

• Provides air sealing for a more comfortable home

• Protects against moisture

• Works well for noise reduction and soundproofing

• High R-value

• Mold and mildew-resistant

• Tax credits available in some states

Disadvantages

• Higher upfront cost than traditional insulation

• May not be DIY friendly to install 

• Potential health risks if exposed for too long or installation isn't done right

• May take longer to install than conventional products

• Can cause eye, skin, stomach, or respiratory irritation*

• Linked to a condition called hypersensitivity pneumonitis

*Most spray foam manufacturers have addressed health issues associated with isocyanates. Side effects are less common than in the past as newer products have largely reduced these issues.

Budgeting for Installing Spray Foam Insulation

Spray foam is a fairly inexpensive choice of insulation material, but it still comes at a higher price when compared to other options, such as looking at the cost of bat and roll insulation. Here are a few tips to reduce the costs of installing spray foam insulation:

• Use open-cell spray foam insulation for all low-moisture areas.

• Look into the federal energy efficiency home improvement tax credit—you may be able to get a tax credit for 30% of your total insulation costs up to $1,200.

• If you have the tools and knowledge to do it, consider taking out old insulation yourself in order to save on insulation removal costs.

• Talk to your local spray foam insulation pro to determine which areas of your home will offer the best energy efficiency for the least insulation cost.

• If possible, install insulation during initial construction rather than an existing home.

How HomeAdvisor Gets Its Cost Data

No place is more important than your home, which is why HomeAdvisor connects homeowners with local pros to transform their houses into homes they love. To help homeowners prepare for their next project, HomeAdvisor provides readers with accurate cost data and follows strict editorial guidelines. We surveyed thousands of real customers about their project costs to develop the pricing data you see, so you can make the best decisions for you and your home. We pair this data with research from reputable sources, including the U.S. Bureau of Labor Statistics, academic journals, market studies, and interviews with industry experts—all to ensure our prices reflect real-world projects.