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How Much Does Spray Foam Insulation Cost? Uses, Types & Cost

close up spray foam insulation

Insulation is an essential part of any home, protecting us from the summer heat and the deep chill of winter. Spray foam insulation is a relatively new type of insulation that’s easy to apply and helps seal air gaps more effectively than traditional insulation.

Let’s check out how much spray foam insulation costs and what you need to know about it to make an educated buying decision.

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The Importance of Insulation

Spray foam insulation is a type of polyurethane-based liquid that expands when exposed to air, making it ideal for filling in stud walls as well as rafter and joist spaces. Unlike regular insulation, spray foam expands to fill and seal even the smallest gaps. Its density and ease of use have made it one of the most in-demand insulation products available.

Insulation is measured in thermal reduction values, also called R-values. The higher the R-value, the better a material insulates. Denser insulation typically boasts higher R-values, but that means a correspondingly higher price point. Spray foam insulation tends to be very dense, and there are two major types. Each has a different R-value and uses.

Spray Foam Insulation R-Values vs. Regular Insulation R-Values:

  • Open-cell spray foam insulation is less dense than closed-cell spray foam, which makes it vapor permeable. Its R-value rates at R3.5 to R4.5 per square inch.
  • Closed-cell spray foam insulation is far denser than open-cell spray foam and resists vapor and moisture while serving as an excellent air barrier. Typical R-values range from R6.5 to R7 per square inch.
  • Cellulose, fiberglass, and other regular insulation typically rate between R3.2 to R2.8 per square inch.

As you can see by these comparative values, spray foam insulates far better than average insulation materials. Both types of spray foam can be used together to create a stronger end result.

walls with spray foam insulation
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How Much Attic Insulation Do I Need?

The amount of insulation you need depends on where you live. For southern climates, you typically need 13–14 inches of insulation. For northern climates, you should have 16–18 inches of insulation in your attic.

How Much Does Spray Foam Insulation Cost?

To calculate how much spray foam insulation will cost, you have to first determine how much area you need to be insulated. Spray foam is typically applied in 1-inch-thick layers, and professionals are experienced at keeping layers uniformly thick.

To calculate how much area you need covered, measure the total length and width of each wall that needs insulation, and multiply those numbers. For example, a 10’ x 8’ wall would result in 80 square feet.

Next, estimate the depth of your stud wall to be filled with insulation. Your regular wall with 2” x 4” studs has a typical depth of 3.5 inches, but this may vary in your home. Multiply your square footage by this depth. To continue with the example we used above, 3.5 inches multiplied by 80 square feet comes to a total of 280. This number signifies how many board feet are to be insulated.

Consult an insulation expert

Find an insulation specialist in your area, and get free, no-commitment estimates for your project.

person applying spray foam insulation in the attic
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Cost of Spray Foam Insulation:

  • Open-cell spray foam insulation costs between $0.44–$0.65 per board foot to install. The result is a flexible, vapor-permeable barrier ideal for ceiling spaces and walls. Open-cell spray foam can serve as the only insulation, but we would suggest supplementing with closed-cell spray foam in moist areas like basements.
  • Closed-cell spray foam insulation costs between $1.00–$1.50 per board foot to apply. The rigidity of closed-cell spray foam makes it an awesome moisture barrier and air barrier, and it insulates like nothing else. If insulation is your only goal, this is the spray foam for you.
  • Labor for this type of work ranges from $50–$100 per hour. This is standard pricing and won’t usually change whether you choose open-cell spray foam or closed-cell spray foam.

Going by these numbers, you can expect to pay between $100–$200 for a 100-square-foot area. A more extensive insulation job for 3,000 square feet would cost between $1,400–$4,500, depending on specific labor and material costs.

To get a more concrete idea of what you may pay, call at least three experienced and reputable contractors to get estimates. This is the best way to figure out what the average prices are for labor and materials in your geographical area.

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Additional Costs to Anticipate

The best time to apply spray foam insulation is during initial construction, and contractors won’t charge as much to install it because the walls are already open and accessible.

If you want to redo your existing home’s insulation, that’s going to cost extra. The contractor will have to remove and replace drywall, which is time-consuming and costly. Expect to pay $1.50–$3.50 per square foot of drywall replaced.

If you opt for open-cell spray foam, you may be required to install a vapor barrier by local building codes. Luckily, closed-cell spray foam insulation can serve as a moisture barrier. This will likely cost $1.00–$1.50 per square foot.

man applying spray foam insulation on the walls
Image Credit: Igor Meshkov, Shutterstock

How Long Does Spray Foam Insulation Last?

Spray foam insulation is made of polyurethane, which is known to last a very long time in its various applications. You can expect a new spray foam insulation job to last 80–100 years if properly installed. 

Closed-cell spray foam insulation is more dense and rigid, so it will last slightly longer than open-cell spray foam. In practical terms, however, the longevity difference is negligible. Most spray foam insulation will last the lifetime of the owner unless severely neglected or improperly applied.

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Spray foam insulation is a new and extremely effective way to insulate your home and keep heating and cooling costs down. It’s relatively expensive to have it done, but spray foam insulation will last virtually forever if applied correctly.

Featured Image Credit: bogdanhoda, Shutterstock


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