How Much Does Spray Foam Insulation Cost in 2025?
The cost to install spray foam insulation depends on the size of the area, the type of insulation you choose, and the application method. Expect to pay an average of $2,886.
You’ll likely pay $1,454 to $4,334, so you can ballpark your budget right away.
Foam thickness, where you put it, and how a pro applies it all change the price.
Because it blocks moisture and dampens noise, spray foam brings perks beyond insulation alone.
Installed the right way, it cuts energy bills and keeps every room more comfortable.
This article was updated using automation technology and thoroughly reviewed for accuracy by HomeAdvisor Editor Ryan Noonan.
Expect to spend about $2,886 on spray foam insulation. Smaller jobs start near $675, while whole-house projects can reach $8,000. Your price hinges on foam thickness, whether you choose open- or closed-cell, and any add-ons like mold remediation. Spray foam insulation costs vary depending on where it’s located—insulating an attic or garage costs more than insulating a crawl space, for instance.
Spray Foam Insulation Cost Factors
Several things push your spray foam price up or down—foam thickness, type, square footage, cleanup, and even the age of your home. Here’s a quick breakdown of different cost factors.
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 |
Open-Cell Foam vs. Closed-Cell Foam
Before you compare open- and closed-cell foam, know that the R-value simply measures how well a material resists heat flow—the higher the number, the better the insulation.
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.
| Foam Type | Cost Installed per Board Foot | Installation per Square Foot |
|---|---|---|
| Open cell | $0.60–$1.60 | $0.88–$3.85 |
| Closed cell | $1.30–$3.10 | $1.44–$4.70 |
Labor
Labor usually tacks on $0.44 to $3.30 per square foot. You’ll pay more if the job calls for thicker foam, tricky locations, or extra prep and cleanup.
Type
Polyurethane is the most common type, costing $0.44 to $1.50 per board foot, while soybean spray foam now costs$1.50 to $3.00 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 won’t stick to an already moldy wall. If a pro has to tackle mold first, budget $1,125 to $3,345 for mold remediation costs before any insulation goes in.
New vs. Existing Home
Installing spray foam in new construction runs about $1 to $4 per square foot. In existing homes, the costs are higher—approximately $3 to $5 per square foot—due to additional labor for opening walls and other modifications. 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
Prices change depending on where you put the foam. Check the ranges below before you book a pro.
| Application Location | Price Range |
|---|---|
| Attic | $1,100–$9,000 |
| Basement walls | $1,500–$6,200 |
| Crawl space | $1,200–$6,900 |
| Roof | $1,500–$7,000 |
| Rim joists | $2,000–$2,300 |
| Garage | $1,500–$9,400 |
| Pole barn or other detached building | $8,000–$30,000 |
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:
$2,886 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
$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 costs more up front than batts or rolls, but it often pays you back with lower energy bills. 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.
Frequently Asked Questions
Insulating a 1,500-square-foot home with spray foam usually costs $1,500 to $7,500. Your total covers both material and labor and changes with foam density, how the pro applies it, and local labor rates. When the job’s done right, you’ll see lower energy bills and enjoy a more comfortable house for years to come.
Adding a 1-inch layer of closed-cell foam to a 30×50 metal building costs about $1,600 to $2,400 for walls only. Extra labor, site conditions, and local rates can nudge that number higher. Talk with a spray foam pro in your area for a firm quote before you start.
For most homeowners, spray foam’s higher upfront price pays off. It seals out drafts and moisture, cuts energy bills, and even stiffens walls for extra strength. Those perks can boost resale value and create a healthier, more comfortable living space for decades.
Two inches of spray foam deliver an R-value of roughly 7 to 13—closer to 13 for closed-cell and nearer 7 for open-cell. R-value measures how well insulation blocks heat, so higher numbers mean better performance. Your actual result depends on the foam type and how the installer applies it.
The amount of spray foam you’ll need depends on your climate, square footage, and the R-value you’re aiming for. Colder regions or drafty homes usually call for thicker layers. A local insulation pro can run the numbers and recommend the right depth so you don’t overspend—or under-insulate.
Spray foam gives off strong odors and VOCs while it cures, so plan to stay out of the space for at least 24 hours. Pros wear full PPE and set up ventilation to keep fumes in check. Hire an experienced installer and follow their timeline before you move back in.
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