How Much Does Spray Foam Insulation Cost?

May 18, 2021 | Home Improvement Repair, Skills Specialties, Tools Materials

Many people weigh the pros and cons of spray foam insulation. The cost of spray foam insulation is a crucial component of the decision-making process. Compared to other types of insulation, spray foam insulation is higher, both for materials and labor costs. Open-cell spray foam can cost between $1 and $1.20 a square foot, while closed-cell can cost $1.25 to $1.50 at 1″ thick.

Spray Foam Insulation Cost (Based On Type)

Unlike other types of insulation, spray foam starts as a liquid. Once sprayed into an empty cavity, the liquid expands to form a hard, dense foam layer that fills the entire space. Spray foam varies by type, being either an open or closed cell. Each layer should harden to 1″ thickness. If you need more protection, you can add additional layers, up to 5″ thick. 

Spray foam layer (1” thick) Performance
1 layer = 1” thick Basic
2 layers = 2” thick Better
3 layers = 3” thick Best
Pro tip: Get used to the term board foot. This is the measurement for spray foam and is equal to one square foot (12” W x 12” L) with a depth of 1”. If you have a 2” layer, it’s two board feet. Two board feet can also be two square feet that’s each 1” deep. 


Open-cell spray foam is cheaper due to its construction. This low-density material is spongier, so it has more flexibility from air bubbles within the polyurethane. These bubbles allow this foam to be great for soundproofing but not for thermal insulation.

This foam costs $0.25 to $0.50 a board foot or $1 to $1.20 a square foot and has a lower R-value (3.5 to 3.6 per inch) with 0.5 pounds density per cubic foot. 

When calculating the costs for open-cell spray, you’ll also need to factor in the price of a vapor retarder (plastic sheets or sheetrock) on interior walls. 


Closed-cell insulation foam costs more – $0.90 to $1.50 a board foot or $1.25 to $1.50 per sq foot. But it has a density of two pounds each cubic foot with an R-value between 6 and 7.14 per inch. The density can be medium or high. 

The R-value refers to how well a product provides thermal insulation. This type of foam has air bubbles full of hydrofluorocarbon or hydrofluoroolefin, making the foam denser. This solid thickness makes the foam airtight and blocks moisture. 

This type of insulation does not need a vapor retarder because it is water-resistant, saving you money on additional supplies. And because the foam stops moisture buildup, there’s no mildew or mold to treat, another avoided expense.


If you’re DIY installing spray foam insulation, you’ll need to calculate your costs by figuring up the price of materials, including the foam, accessories (underlay, cleanup), and equipment. You’ll want to use protective gear when working with spray foam, as it can cause eye, skin, and breathing irritation. At a minimum, you’ll want gloves, safety goggles, full body clothing, and a mask or face ventilator. A painter’s mask would also work if you have one handy. 

Which type of system you’re using will affect the costs. You may be able to rent a unit, or you can purchase one within your budget. Check out our reviews on five of the best spray foam insulation kits if you’re in the market for a system.

When factoring in materials, consider the size of the area in square feet of the location you’ll be spraying. Refer to the chart for the price by square feet. Use the formula sq ft x inches depth to determine how many board feet of foam you’ll need for the area. Then multiply the board feet by the price to get the final cost. 

Square Feet Price
100 $44-$150
200 $88-$300
300 $132-$450
400 $176-$600
500 $220-$750
1,000 $440-$1,500
1,500 $660-$2,250
2,000 $880-$3,000
2,500 $1,100-$3,750
3,000 $1,320-$4,500
  • Based on one board foot (12” x 12” x 1” thick)
  • Price increases with each additional layer


Depending on the area you want to insulate, you may need to contact a professional to handle the job. Small tasks like filling holes in the foundation or small cracks around your doors and windows can be handled DIY. 

But if you need to insulate wall cavities, crawl spaces, attics, basements, or other large areas, it’s best to leave the task to a professional. Each layer of insulation needs to be applied in a 1” layer evenly to get the proper protection. 

The costs for installing spray foam by a professional can vary by location and contractor, which is why it’s a good idea to get pricing from a few different people before choosing. 

Typically, the cost is around $1 to $1.50 a square foot (between $500 and $750 for 500 sq ft) for installation. For labor, you’ll pay between $40 and $70 each hour. 

Pro tip: When debating on what R-value you need, consider your climate. If you live in a hot climate, you’ll do best with a R-value of 30. Cold climates would need an R-value around 49, while temperate climates need somewhere in the middle – R-38 is appropriate.

Spray Foam Insulation Cost vs. Other Methods

There are multiple methods of insulation and installation. Spray foam is a more expensive process compared to other options, both for materials and professional labor costs. Let’s look at the costs of different techniques compared to spray foam. 

Injection Foam

A similar method of insulating your structure is injection foam, which can go into any closed cavity without causing damage to the surrounding system (drywall). 

This method requires making a small injection hole, requiring more minor repairs or cleanup. Since the solution is pre-mixed, there’s less cost of labor. 

The final price of this type of foam depends on thickness, ranging from $0.44-$1.50 for 1″ thickness up to $1.76-$6.00 for 4″ thick foam.

This type can be difficult to DIY without experience, so you may want to check with different contractors to compare pricing before deciding on a company. 

Fiberglass Batt

It can cost two to three times more to install spray foam insulation than installing conventional fiberglass insulation, which costs around $0.40 a square foot for materials. This option is a long narrow sheet of fiberglass material covered by protective paper that fits in the empty gaps between studs to reduce air flow.

Fiberglass batting varies by color and thickness. Which type you should choose will depend on your location and which R-value you need. 

The cost of having a fiberglass batt professionally installed is also cheaper than professionally installing spray foam since this process isn’t as complex (given there isn’t any tear-down or repairs needed). It’s an ideal solution for attics, crawlspaces, or wall cavities where there’s large empty areas to fill.  

However, this material will not allow you to save money with energy-efficiency, as fiberglass insulation is not as solid as foam. It reduces wind drafts but won’t stop them completely. 

The cost of materials varies from $0.64 to $1.18 per square foot, costing between $145 and $200 for 500 square feet. This method is easy to DIY since all you need to install the material is a putty knife, measuring tape, and a utility knife to cut the pieces to size. 

For a professional to do the job for you, you’ll have to pay for materials plus the cost of labor, which can range from $150 to $300. Depending on the size of the space you’re insulating, the job can take up to six hours, costing $300 to $500 in labor alone.

You’ll also want to take into consideration the lifespan of fiberglass insulation, which can be from 10 to 25 years, if kept dry. And because the R-value drops over time, fiberglass will start to lose performance as it ages. 

You’ll have to pay the costs of replacing fiberglass insulation two to three times compared to the one-time cost of spray foam insulation, which lasts a lifetime. 

Blown-in Insulation

Another type of insulation is blown-in, which can be done professionally or DIY. There are multiple types of blown-in insulation and three types of applications – loose fill, wall-cavity spray, or stabilized.

Loose-fill fiberglass is spun (or blown) fibers made with glass. This type of insulation requires a blowing machine to install. Blown-in insulation is suitable for wall cavities or attics to prevent mildew, moisture, and fungus. But it can cause particles of fiberglass to float in the air. 

Applying a netting or membrane helps prevent fiberglass particles from escaping. Some netting is odorless, chemical-free, fire-resistant fiberglass with a 4.2 R-value per inch. Without a netting, blown-in insulation has an R-value of 3.2 per inch. 

Cellulose is another material used for blown-in insulation. This material is made with recycled newsprint and corrugated cardboard and treated with fire retardant (borate) and is common for homes. This material costs around $0.32 a square foot, with pricing ranging from $500 for DIY to anywhere from $1,500 to $2,000 (1,500 sq ft). 

This material also has a shorter lifespan of 20 to 30 years, requiring reapplication two to three times in the same timeframe as the lifespan of spray foam. And it loses R-value over time, reducing its performance.

Radiant or Reflective Barrier

This type of insulation is primarily used in attics where there’s intense summer heat or brutal cold temperatures in the winter. Radiant barriers can help reduce your energy bills while adding to your home’s R-value. 

This type of insulation can vary by design but all share a similar function – thermodynamics. Rather than slowing down heat flow, radiant barriers absorb radiant heat, allowing your attic to remain cool.

A reflective barrier contains cardboard, air infiltration board, plastic films, and strand board, topped with a reflective aluminum-based layer. Some types are double-sided, which cost more.

These barriers can earn you up to 10% (around $150) in annual savings on energy costs. Although if you live in a colder climate, you may not see as much savings as in a hot location. 

Pricing for this type of insulation can vary by product and type (boxed or rolled), ranging from $0.15 to $0.30 a square foot. It can cost between $175 and $325 to insulate a standard 500 square foot attic. If you plan to use a professional for installation, you’ll have additional labor costs ranging between $500 and $750. 

Where to Use Spray Foam Insulation

Spray foam insulation has many uses, both in the house and out. You can use this product anywhere you need to seal cracks or gaps to block air, pests, or water. Spray foam insulation can be added to your home during new construction or existing structures during remodels.

Due to the higher costs of spray foam insulation, many people limit the uses of spray foam insulation to major areas of the home that need superior insulation, including:

  • Exterior framing (doors, windows, foundation, hardware, ventilation)
  • Attic space (ceiling joists) ($2,200 for a typical-sized attic)
  • Basements ($2,140 using closed-cell foam)
  • Crawl space ($80 per 20 square feet)
  • Roof joists ($1,650 to $2,200)
  • Garage ($200-$600 for 750 sq ft) 
  • Barns ($740 to $2,540 for 1,200 sq ft w/ 12’ ceilings)

Pros and Cons Of Spray Foam Insulation

There are many benefits to spray foam insulation, making it one of the most common types of insulation now used for new builds and remodels. 

One of the most significant benefits is that it can significantly increase your home’s energy efficiency, allowing for cheaper electric bills (up to 50% savings). Spray foam can expand 40 to 100 times the original size, creating a solid seal that can reduce or block air and moisture (depending on the type). 

This expansion not only keeps the air outside from coming in to create drafts, but it also keeps the air trapped inside and easier to keep the same temperature. Not having air coming in from outside also prevents moisture and humidity, condensation, and mold. Fiberglass insulation will not stop these issues.

And because spray foam starts as a liquid, it’s easier to use in tight spaces like nooks and cracks where traditional insulation might not fit.

Spray foam insulation is also Class A fire rated (highest possible), allowing it to keep your home safer than other insulation types. 

The biggest downside of spray foam insulation is that it costs more to install, regardless of whether you’re DIY’ing or you’ve hired a professional installer. 

How Spray Foam Insulation Is Installed

The installation of spray foam varies depending on the type of unit used. Most professionals will use a system that consists of two separate tanks of chemicals (A side-isocyanate, B side-fire retardant resin). The resin has to be correctly agitated before use, so the retardant mixes with the resin. Each mixture should also be around 770℉ before applying.

These chemicals move into the proportioner, which controls how much each product gets mixed and heats it to the appropriate temperature. Another hose goes from the proportioner to the spray gun. Inside the gun head is a blending chamber that mixes the contents of sides A and B and expels it in a pressurized spray.

As the solution comes in contact with a surface, it expands and hardens into a solid piece of foam. Open-cell foam will have a softer texture than closed-cell foam.

Spray Foam Insulation Cost FAQ

We conclude this informative article about spray foam insulation cost by covering a few frequently asked questions customers have about the topic. 

Is spray foam insulation worth it?

Spray foam has many benefits, but it’s also an expensive solution. Despite the higher costs of materials and labor, the money you’ll recoup from energy efficiency will cover your investment in as little as three years. 

How long does spray foam insulation last?

Spray foam is a lifetime product due to being an inert polymer (a material similar to plastic). Once installed, it can last the same length of time as your home. Once you install spray foam insulation, you’ll never need to replace it (unless it becomes damaged, such as by mice). 

How much does it cost to spray foam a 2,000 square foot house?

The cost of materials for a 2,000 square foot house can range from $880 to $3,000. The cost can vary by type of spray foam, the location, and whether you’re doing it yourself or hiring someone. 


The many benefits of spray foam insulation have made it one of the most popular types of insulation used today for remodels, new builds, and repairs. Although it costs more initially, spray foam insulation can save you more money over time than you spend to install it. When installed properly, spray foam insulation can reduce energy bills by up to 50% annually. 


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