How Much Does It Cost to Install Spray Foam Insulation?

Average range: $10,000 - $30,000
Low
$6,000
Average Cost
$20,000
High
$40,000
(Mixture of open and closed cell insulation for an existing 2,000 sq.ft. home)

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How Much Does It Cost to Install Spray Foam Insulation?

Average range: $10,000 - $30,000
Low
$6,000
Average Cost
$20,000
High
$40,000
(Mixture of open and closed cell insulation for an existing 2,000 sq.ft. home)

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Reviewed by Isabel Maria Perez. Written by Fixr.com.

With the rising energy costs, many homeowners are turning to insulation to cut energy usage. Many insulation types are on the market, and spray foam is one of the most effective at insulating and creating an air and vapor barrier. It can be used in areas where other forms of insulation cannot go, and it can last up to 80 years without degrading.

Many factors determine spray foam insulation costs, including the amount, depth, and insulation type. The national average cost to fully insulate a home with spray foam is $10,000 to $30,000. Most homeowners spend around $20,000 on a mixture of open and closed cell insulation 6 inches thick in an existing 2,000 sq.ft. home. This project’s low cost is around $6,000 for 4 inches of open cell foam covering the attic floor. The high cost is $40,000 for 10 inches of closed cell foam insulation in an existing 3,000 sq.ft. home.

Cost to Install Spray Foam Insulation

Spray Foam Insulation Cost
National average cost$20,000
Average range$10,000-$30,000
Minimum cost$6,000
Maximum cost$40,000


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Spray Foam Insulation Cost by Project Range

Low
$6,000
4 inches of open cell foam covering only the attic floor
Average Cost
$20,000
Mixture of open and closed cell insulation for an existing 2,000 sq.ft. home
High
$40,000
10 inches of closed cell foam insulation in an existing 3,000 sq.ft. home

What Is Spray Foam Insulation?

Spray foam insulation is polyurethane mixed with water or another fluid before being sprayed into the walls. The foam expands quickly upon installation before hardening. Because it sprays in a liquid form, it can be applied to wall cavities and other hard-to-reach areas in new and existing homes. Applying the correct depth - at least 6 inches for closed cell and 8 inches for open cell insulation - can dramatically reduce thermal transfer. This makes your home more comfortable and energy-efficient.


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Spray Foam Insulation Cost by Type of Installation

Spray foam insulation is more common in new home construction than in existing homes. It is easier to add foam to wall cavities, basements, and other areas before they are finished in new home construction. It takes more work and effort to get the spray foam into wall cavities in finished walls in an existing home. While material costs do not change, the cost of installing in an existing home can be much higher than in a new home. You may have further costs in patching walls and other finish work once the insulation is in. That is why most people who want to add insulation to an existing wall cavity choose blow-in insulation rather than spray.

For areas like attics and other open spaces, spray foam insulation is applied similarly to a new home. If you insulate your entire existing home with spray foam insulation, you do not pay more for the insulation. But you have additional finishing costs associated with the project.


Cost per Sq.Ft. to Install Spray Foam Insulation in New Home Construction or in Existing Walls

Cost per Sq.Ft. to Install Spray Foam Insulation in New Home Construction or in Existing Walls


Type of InstallationAverage Cost per Square Foot (Installed)
New Construction$2.75 - $6.50
Existing Walls$3.15 - $7.50


Spray Foam Insulation in New Home Construction

Adding spray foam insulation to new home construction costs between $2.75 and $6.50 a square foot installed. Costs vary due to several factors. The foam depth is the biggest contributing factor. Most need to be installed between 6 to 12-inches thick to have a significant impact on your comfort and energy bills. However, not every area needs the same thickness of insulation. In addition, there are two types of insulation - open and closed cell. While closed is technically more expensive, you can often get away with less of it. Depending on where it is installed, this can impact your final costs.

Spray Foam Insulation in Existing Walls Cost

The cost to install spray foam insulation in existing homes is $3.15 to $7.50 a square foot. Adding insulation to an existing home has the same cost factors and variables as a new home installation. Thickness and location change the cost of the project dramatically. In addition to these factors, you also have accessibility to contend with. While some areas in an existing home are identical in accessibility to a new home, other areas are hard to reach. Existing finished walls require the installer to open the walls in certain areas. This can add to the insulation cost and finishing costs.

Spray Foam Insulation Cost per Square Foot

Spray foam insulation has a wide range of costs per square foot. This is because it is actually sold and installed by the board foot. A board foot of spray home insulation is defined as 1 square foot of space covered in 1 inch of insulation. You will never purchase a board foot because the insulation you need ranges from 6 to 12 inches, and the amount varies based on the location and insulation type. This means square footage costs vary widely. You rarely use the same amount and insulation type in your entire home. It is much more likely to switch types and thicknesses throughout the project. The costs below are for a broad range of what you could pay based on the number of square feet you cover. Keep in mind your costs could fall anywhere within the range based on your needs. The table below shows the insulation square footage, not the square footage of the house.


Cost to Install 100, 200, 300, 400, 500, 1,000, 1,500, 2,000, 2,500, or 3,000 Sq.Ft. of Spray Foam Insulation in an Existing Home or New Construction

Cost to Install 100, 200, 300, 400, 500, 1,000, 1,500, 2,000, 2,500, or 3,000 Sq.Ft. of Spray Foam Insulation in an Existing Home or New Construction


Size in Square FeetAverage Cost in an Existing House (Installed)Average Cost in New Construction (Installed)
100 sq.ft.$315 - $750$275 - $650
200 sq.ft.$650 - $1,500$550 - $1,300
300 sq.ft.$965 - $2,250$825 - $1,950
400 sq.ft.$1,300 - $3,000$1,100 - $2,600
500 sq.ft.$1,575 - $3,750$1,375 - $3,250
1,000 sq.ft.$3,150 - $7,500$2,750 - $6,500
1,500 sq.ft.$4,725 - $11,250$4,125 - $9,750
2,000 sq.ft.$6,300 - $15,000$5,500 - $13,000
2,500 sq.ft.$7,875 - $18,750$6,250 - $16,250
3,000 sq.ft.$9,450 - $22,500$8,250 - $19,500


Spray Insulation Cost by Category

Spray foam insulation has two categories - open and closed cells. This describes the way the foam looks. Of the two, closed cell is better at insulating. It is also stronger, harder, and more difficult to place in tight areas like around pipes. Closed cell is also water-resistant, meaning it works on exterior walls.

Open cell typically must be thicker to achieve the same insulating power as closed cell. For example, 8 inches of open cell insulation or 6 inches of closed cell reach the same R-factor. For this reason, while open cell is less expensive, you use more overall. This means that functionally, there is little-to-no difference in costs between the two materials once they are installed.


Cost per Board Foot of Open Cell or Closed Cell Spray Foam

Cost per Board Foot of Open Cell or Closed Cell Spray Foam


CategoryAverage Cost per Board Foot (Material Only)
Open Cell$0.44 - $0.65
Closed Cell$1.00 - $1.50


Open Cell Spray Foam Cost

Open cell spray foam costs between $0.44 and $0.65 a board foot for the material. Open cell is created through lower pressure and has a more open structure. That means air and moisture can pass through the foam. It does not provide as high an R-value as closed cell and is not waterproof or water-resistant. You need more material to cover the same-size space, so while it costs less, you use more of it. This results in nearly identical costs. It is used solely for interior purposes. It gets into tight spaces better than closed cell so that it can fit in tight corners and around pipes in existing home installations better than closed cell.

Closed Cell Spray Foam Cost

Closed cell insulation costs $1 to $1.50 a board foot for the material. Closed cell is produced under high pressure, which closes the openings in the foam. It costs more than open cell, but you use less for the same R-value. It is also incredibly strong. It can add strength and structural integrity to your home, and a smaller amount does a better job at insulating. It keeps water and moisture out but does not allow for permeability, which is a problem that can lead to mold. You can use this material on exterior applications and basements, and it can adhere to materials like PVC, brick, mortar 1, and wood.


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Spray Foam Insulation Price by Type of Makeup

Most spray foam insulation contains polyurethane as a base. Not all are created equally, however. Some are made of greener materials than chemicals typically used in polyurethane production. Choosing a different spray foam can create a healthier home while avoiding some of the off-gassing polyurethane is known for. While traditional polyurethane is the most common type, you may also find soy-based, water-based, and vegetable-oil-based options. Your project’s cost ranges from $2.75 to $7.50 a square foot, regardless of which type you use because of other factors like location, installation type, and foam thickness.

Traditional Polyurethane Spray Foam Insulation

Unless your installer tells you differently, the material installed for your spray foam is probably traditional polyurethane. This is a chemical base often containing high levels of VOCs, meaning the material has a strong odor. It also means it may release these VOCs. Most off-gas about 50% in one year and the remaining 50% over the next 4 to 5 years. While this is not dangerous, some people are sensitive to the VOCs, which can cause headaches and minor respiratory upset.

Soybean Spray Foam Insulation

Soybean spray foam insulation is a much healthier and more sustainable choice for homes. Most polyurethane contains formaldehyde or urea, both of which can off-gas. Soy production means your spray foam does not give off hazardous VOCs. Soybeans are also readily available and easily planted. This creates a more sustainable material for your home. Using this insulation might help your home attain LEED credits for green building.

Water-Based Spray Foam

Another good alternative to polyurethane is water-based spray foam. This is unique insulation that uses organic petroleum-based chemicals mixed with water. It is not as sustainable as soy-based foams, but it also does not emit any VOCs. Water-based spray foam is only available as open cell insulation. This means it may not be the best fit for all areas. However, for small indoor projects, this can be a good way to create a healthier space for both the installer and residents.

Vegetable Oil Spray Foam Insulation

Sometimes, you see soy-based spray foam called vegetable-oil-based. It is essentially the same thing. Rather than using a chemical to create polyurethane, they use soybean oil. This means the spray foam is greener, more sustainable, healthier, and does not off-gas like normal polyurethane foams. And because soybeans can be grown sustainably, this can help your home achieve LEED credits.

What Is the R-Value of Spray Foam Insulation?

All insulations are ranked on how well they resist thermal transfer. This is known as the R-value, and a higher R-value means it resists more thermal transfer.

In general, closed cell spray foam has a higher R-value per inch than open cell. The R-value of each increases with the thickness. For example, a 2-inch open cell application may have an R-value of 7.6, while a 3-inch application might have an R-value of 11.4. The same thicknesses of closed cell have R-values of 14 and 21, respectively.

The amount of spray foam you need to achieve the recommended R-value for your home varies by the location you install it in and where you live. Check this guide by Energy Star to find the recommended R-value for the various areas of your home, based on the climate you live in.

Spray Foam Cost by Thickness

Spray foam can be applied in many thicknesses. You likely do not need more than 6 to 7 inches of closed cell, even in extremely hot or cold climates. However, you may need much more open cell to achieve the same level of insulation. On average, an inch of closed cell foam has an R-value of 7, while an inch of open cell has an R-value of 3.8. Your exact numbers vary depending on what you apply and the foam your installer uses. Below is an average range of R-values and costs for applying the foam by inch.

Closed Cell Insulation Cost by Thickness


R-Value and Cost of a 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10-Inch Closed Cell Foam

R-Value and Cost of a 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10-Inch Closed Cell Foam


ThicknessR-ValueAverage Cost (Material Only)
1 Inch7$1 - $1.50
2 Inches14$2 - $3
3 Inches21$3 - $4.50
4 Inches28$4 - $6
5 Inches35$5 - $7.50
6 Inches42$6 - $9
7 Inches49$7 - $10.50
8 Inches56$8 - $12
9 Inches63$9 - $13.50
10 Inches70$10 - $15


Open Cell Insulation Cost by Thickness


R-Value and Cost of a 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10-Inch Open Cell Foam

R-Value and Cost of a 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10-Inch Open Cell Foam


ThicknessR-ValueAverage Cost (Material Only)
1 Inch3.8$0.44 - $0.65
2 Inches7.6$0.88 - $1.30
3 Inches11.4$1.32 - $1.95
4 Inches15.2$1.76 - $2.60
5 Inches19$2.20 - $3.25
6 Inches22.8$2.64 - $3.90
7 Inches29.6$3.08 - $4.55
8 Inches30.4$3.52 - $5.20
9 Inches34.2$3.96 - $5.85
10 Inches38$4.40 - $6.50


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Spray Foam Installation Cost

Labor costs to install spray foam insulation vary depending on the insulation’s new location, installation type, accessibility, and how much you apply. Costs for labor are typically between $50 and $100 per hour. The amount of time needed depends on the job size. For example, spraying a small basement takes 2 to 3 hours, whereas a large attic could take 6 to 8 hours, and an entire house may take 3 to 4 days. The more accessible the area, the faster the installation and the lower the costs.

The labor for spraying a 2,000 sq.ft. home costs between $1,200 and $4,800 out of the $20,000 total. Some installers may also include additional costs for equipment, and you may also have setup costs.

Costs for labor do not vary tremendously based on open cell or closed cell because the process is the same. The amount of insulation, location, and accessibility dictates your labor, while the material cost drives the remainder.

Spray foam insulation looks deceptively easy to install. It consists of two large drums, each holding a separate chemical mixture. The first contains the insulation. The other has a catalyst that turns it into foam, along with a combination of control agents that specify how big it gets, how far it spreads, and other factors. These two chemicals are heated and mixed under pressure while being sprayed directly at the surface they cover. The foam begins to expand up to 150 times its original size within seconds. Therefore, the installer must calculate where and how much to spray to fill the area.


Installed Spray Foam Insulation in New Construction


Spray Foam Installation Cost by Brand

In some instances, you choose an installer for your spray foam, and they provide you with their preferred insulation brand. In other cases, you may choose the brand you want, and then find someone certified in its installation. Several good manufacturers are on the market, but keep in mind that none sell directly to the public. You must choose a certified installer. Installers quote your project and determine the final costs per square foot. This is because every application differs, and equipment costs vary by area. Most spray foam installations fall between $2.75 and $7.50 a square foot, regardless of the brand. Below are some of the most common brands to choose from.

Icynene Insulation Cost

The cost of Icynene insulation ranges from $2.75 to $7.50 a square foot installed. Final costs are dictated by the installer, not the foam manufacturer. Shop around to get the best rates in your area. Costs are dependent on factors like thickness and location. Icynene uses a water-and-petroleum mixture to make its foam. It is lower in VOCs and a healthier option than some alternatives.

RetroFoam Cost

The cost of RetroFoam averages $2.75 to $7.50 a square foot installed. Final costs are dictated by installers and not the manufacturer. This means you may be able to shop around for the best rate. RetroFoam is made by the parent company Polymaster. They have been producing spray foam insulations for more than 20 years. RetroFoam is designed for injection into existing wall cavities, making it suitable for many homes.

Lapolla Spray Foam Cost

The cost of Lapolla spray foam is $2.75 to $7.50 a square foot installed. The people who install your spray foam set the cost rather than the manufacturer. So, shop around for the best price. Lapolla is a closed cell foam designed to bring high performance to homes. It can be used for retrofitting or for new installations. The material can effectively seal against both moisture and air, making it ideal for all areas.

Walltite Insulation Cost

The cost of Walltite insulation ranges from $2.75 to $7.50 a square foot installed. The brand does not set the costs of what you ultimately pay. These costs are set by the installer. This enables you to shop for the best costs in your area. Walltite is a general spray foam polyurethane. It can be used on interiors and exteriors and has good adherence to all surfaces.

Cost to Install Spray Foam by Location

While some people may choose to spray foam their entire home, others only want to insulate specific areas such as their attic or basement. Costs are typically higher for existing structures than for new construction, and final costs are based on factors like thickness and foam type.

Below are the average costs based on typical sizes, assuming all relevant areas have been insulated. In some areas, such as attic floors, basements, and crawl spaces, costs are identical for existing and new construction because access remains the same.


Cost to Install Spray Foam Insulation in an Existing House or New Construction by Location: Crawl Space, Basement, HVAC, Attic, Garage, Pole Barn, Whole House...

Cost to Install Spray Foam Insulation in an Existing House or New Construction by Location: Crawl Space, Basement, HVAC, Attic, Garage, Pole Barn, Whole House...


LocationAverage Cost in an Existing House (Installed)Average Cost in New Construction (Installed)
Crawl Space$1,000 - $5,900$1,000 - $5,900
Shipping Container$1,800 - $2,500$1,800 - $2,500
Roof$2,400 - $8,000$2,400 - $8,000
Basement$2,400 - $8,400$2,400 - $8,400
HVAC$2,500 - $3,000$2,500 - $3,000
Attic$2,500 - $12,000$2,500 - $8,000
Garage$4,000 - $8,600$3,600 - $7,800
Pole Barn$8,000 - $20,000$6,000 - $18,000
House$10,000 - $30,000$8,000 - $25,000


Cost to Spray Foam a Crawl Space

The cost to spray foam a crawl space is between $1,000 and $5,900. Crawl spaces are rarely finished or insulated in new homes. This is because of how they are created and how they may be used in the future. However, insulating them can make a big difference in your energy bills and comfort. The floor above your crawl space is often more comfortable after insulating rather than taking on the outdoor temperature. Due to how they are constructed, insulating in new construction or an existing space has similar cost ranges.

Cost to Spray Foam a Shipping Container

The cost to spray foam a shipping container ranges from $1,800 to $2,500. Shipping containers have become popular for use in various ways. This includes creating homes and workspaces from them. It does not have new build costs because you are repurposing the space. Spray foam is the ideal insulation for a shipping container. It sticks to the metal and goes on quickly and easily without needing cavities.

Roof Foam Insulation Cost

The cost to spray foam your roof deck averages $2,400 to $8,000. However, spray foam is not always recommended for this space. If you choose to apply spray foam to your roof deck, you must use closed cell foam. This is because moisture can infiltrate this area. This can mean that roof leaks and other problems go undetected for longer, leading to bigger repairs down the road. Because the roof deck is fully accessible in existing homes and new builds, there is no cost difference.

Cost to Spray Foam a Basement

The average cost to spray foam a basement is $2,400 to $8,400. Due to how basements are created, the cost is the same in an existing home as in a new build. Spray foam is a great way to insulate all areas of the basement. It does well on concrete, around pipes, and HVAC equipment. Only closed cell foam can be used here because of the high moisture levels in basements. Spray foam can be added at any time to a basement but is most often done before finishing.

HVAC Spray Foam Insulation

The cost to spray foam your HVAC system averages $2,500 to $3,000. Spray foam insulation is an excellent choice for sealing the area around an HVAC system to prevent air loss and improve efficiency by having the unit not work as hard. It does this by expanding to fill all air gaps in the system. You use spray foam on ducts, connections, exhaust, and other areas where air leaks or air gaps may be discovered. The best way to find out where to insulate is to have your system inspected and tested for air leaks and then insulate. This can be done after the system is installed.

Cost to Spray Foam an Attic

The cost to spray foam an attic ranges from $2,500 to $12,000. There are many areas in an attic you can spray. Costs may fluctuate between new construction and an existing home, but may not, depending on what you have in the attic. Spray foam can be applied to the attic floor, walls, ceiling, and roof deck underside. This is best used in unfinished attics because it is quick and easy to apply. However, it can be added to finished spaces, adding to the cost of an unfinished attic installation.

Cost of Spray Foam Insulation in a Garage

The cost to spray foam a garage is $3,600 to $7,800 for a new or unfinished garage. Costs for an existing finished garage average $4,000 to $8,600. Unfinished garages and new garages have similar costs for installation. It is only after the garage is finished that the cost rises. Spray foam is an excellent material for garages. It can be applied to all areas, including the back of the garage door and the ceiling. If your garage is attached to your home, this can make it more comfortable and help prevent it from becoming a source of energy leaks.

Cost to Spray Foam a Pole Barn

The cost to spray foam a pole barn ranges from $6,000 to $18,000 for a new build. The cost to insulate an existing pole barn is $8,000 to $20,000. Many people choose pole barns to build as a home, barn, or other outbuilding structure. They are fast and easy to put up, which generally makes them inexpensive. However, they can be harder to insulate using other methods. Spray foam can cover all areas and air leaks in the structure. This means a much more comfortable and energy-efficient structure once complete.

Cost to Spray Foam a House

The cost to spray foam a new home averages $8,000 to $25,000. The cost to spray foam an existing home is $10,000 to $30,000. Spray foam makes a great choice for all home types. It expands to fill areas of many sizes, including some that may be hard to fit with fiberglass batts and other traditional insulation types. It is also fast and easy to apply, so it can often be done in less time than other insulation types. The insulation amount and type used in the space vary throughout the house. You will likely need a combination of thicknesses and open and closed cell insulation.


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Calculating Spray Foam Costs

Many factors go into calculating the final costs of your spray foam insulation project. The first is the location where the foam is used. Some areas only need 3 to 4 inches of foam, while others may need up to 10 inches. While most homes average around 6 inches, you will most likely need a combination of open and closed cell and different thicknesses.

Next, your climate plays a role in what the best R-factors are for the different areas. Homes in very hot and very cold climates need more insulation than homes in moderate climates. If this is an existing home, you likely already have some insulation in place. This also needs to be taken into consideration when determining the correct amount of spray foam to add.

That is why general cost ranges for spray foam insulation are large. Your project can have a wide range of influencing factors that ultimately determine your cost. To get the best cost calculation for your home, contact an installer and have an assessment done.


Professional Installing Spray Foam Insulation


Pros and Cons of Using Spray Foam

Like any material, spray foam insulation has advantages and disadvantages. The material is made up of two liquids heated and sprayed together. On contact, they expand to fill the cavity. The material is quick and relatively easy to apply. It also fills gaps, no matter how small, and can be used around things like pipes and ducts where fiberglass batts may not be able to go.

Spray foam offers superior insulation in many instances to other forms. You can get very high R-values with spray foam, often with less insulation needed than other types. Spray foam also acts as a sound barrier, so your home can be quieter.

Unfortunately, spray foam has several drawbacks. Some types give off high levels of VOCs, which may be irritating. Because there are two types, you must apply it professionally to ensure it is done correctly and the correct product is used in the right area. Trying to save on a DIY insulation job is not possible with spray foam. Finally, it is not always the right insulation for the job. For example, using it on a roof deck may obscure water leaks until too much damage has been done.

How Long Does Spray Foam Insulation Last?

It is estimated that spray foam insulation can last for up to 80 years. While this seems like a long time, other insulation types like fiberglass and cellulose last for more than 100 years. For many homeowners, however, 80 years is much longer than they own the property, making it a good investment from a resale and energy cost savings standpoint.

Spray Foam vs Fiberglass Insulation

Spray foam is one type of insulation. Another more readily recognizable form is fiberglass 2. Fiberglass insulation comes in batts and loose-fill. It is much healthier than spray foam because it does not emit VOCs. It also does not degrade when wet, but it should not be used on exterior walls. So, it can be more limited in placement than spray foam. Fiberglass is also the least expensive insulation on the market.


Comparison of the Cost per Sq.Ft. to Install Fiberglass or Spray Foam Insulation

Comparison of the Cost per Sq.Ft. to Install Fiberglass or Spray Foam Insulation


Insulation TypeAverage Cost per Sq.Ft. (Installed)
Fiberglass$0.64 - $1.19
Spray Foam$2.75 - $7.50


Rockwool vs Spray Foam

Rockwool or mineral wool is another insulation used in homes. It is not used nearly as frequently as fiberglass or spray foam. It does not emit as many VOCs as spray foam, but it can contain formaldehyde. Rockwool is made in stiff lightweight batts. It cannot be used in all areas that spray foam can and is limited to stud interior walls. It does a good job of thermal insulating and soundproofing, but it is not as versatile as spray foam because it cannot be used in as many places.


Comparison of the Cost per Sq.Ft. to Install Rockwool or Spray Foam Insulation

Comparison of the Cost per Sq.Ft. to Install Rockwool or Spray Foam Insulation


Insulation TypeAverage Cost per Sq.Ft. (Installed)
Rockwool$0.65 - $2.50
Spray Foam$2.75 - $7.50


Blown-In Insulation vs Spray Foam

When insulating an existing home, consider blown-in insulation in addition to spray foam. Blown-in insulation can be fiberglass or cellulose. It is made up of loose material that can be blown into a cavity, propelled by air. It is less expensive than spray foam and healthier with no VOCs. However, it often does not insulate as well and cannot be used in open spaces like how spray foam insulation can.


Comparison of the Cost per Sq.Ft. to Install Blow-In or Spray Foam Insulation

Comparison of the Cost per Sq.Ft. to Install Blow-In or Spray Foam Insulation


Insulation TypeAverage Cost per Sq.Ft. (Installed)
Blow-In$1.00 - $1.50
Spray Foam$2.75 - $7.50


Cellulose Insulation vs Spray Foam

Cellulose insulation is a type of blown-in insulation made of cellulose from paper. It is treated to be flame-retardant before being used in the cavities. It is eco-friendly, does not emit VOCs, and is best inside cavity walls in existing homes. Unlike spray foam, it cannot be used in open areas or on exterior walls. This makes spray foam the more versatile of the two.


Comparison of the Cost per Sq.Ft. to Install Cellulose or Spray Foam Insulation

Comparison of the Cost per Sq.Ft. to Install Cellulose or Spray Foam Insulation


Insulation TypeAverage Cost per Sq.Ft. (Installed)
Cellulose$1.00 - $1.50
Spray Foam$2.75 - $7.50


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Enhancement and Improvement Costs

Soundproofing

Spray foam insulation acts as an acoustic absorber, helping stop some sounds from entering. While you can use it as a sound barrier, you may want to take this a step further. Soundproofing a room to truly improve the acoustics costs around $1,000 to $2,500.

Mold Remediation

One reason to install new insulation is to remove old insulation affected by mold from moisture infiltration. If this is the case, you need mold remediation before installing the new material to ensure the area is clean and ready for new insulation. The cost for mold remediation is between $1,500 and $3,500.

Humidity Repairs

Closed cell insulation acts as an air barrier, meaning water vapor cannot escape. In some instances, you may need to have a vapor barrier 3 installed to prevent issues from occurring. This is not always the case, but it costs between $0.65 and $1 a square foot if needed.

Additional Considerations and Costs

  • Moisture. Closed cell insulation is water-resistant and not affected by water. Open cell insulation does not keep water out, so moisture passes through it, meaning it cannot be used on exterior walls or in areas of high moisture.
  • Strength. Spray foam insulation does not rot or degrade, even when wet. It can add considerable strength and structural integrity to many areas.
  • Energy audit. Having an energy audit conducted before installing insulation can help find the best areas to insulate.
  • Professional installation. Spray foam insulation must be installed by a professional. In addition to requiring specialized knowledge, it may be hazardous to the health of the installer if handled incorrectly.
  • Air barrier. Closed cell insulation creates a very tight air barrier. Used on the building envelope, it may lead to a buildup of interior condensation. Use a vapor barrier to prevent this.

FAQs

  • How much does it cost to insulate a 1,500-square-foot house?

Costs vary depending on the insulation type and amount. Costs range from $8,000 to $26,000.

  • Is spray foam insulation worth it?

This depends on what your end goal is and where you are insulating. It is a very effective form of insulation for sealing air gaps.

  • What is the R-value of 2 inches of spray foam?

For closed cell spray foam, the R-value is 14. For an open cell, the R-value is 7.6.

  • How long does spray foam roofing last?​

Spray foam insulation lasts roughly 80 years before beginning to deteriorate.

  • Should I use spray foam insulation in my attic?

Open cell spray foam insulation is a great choice for attics. It can be used to cover floors and walls.

  • Can mold grow on spray foam insulation?

Spray foam insulation resists the growth of mold and mildew.

  • Do you need a ridge vent with spray foam insulation?

A ridge vent 4 provides ventilation to your attic, which is necessary regardless of the insulation type.

Remodeling Terms Cheat Sheet

Definitions in laymen's terms, cost considerations, pictures and things you need to know.
See full cheat sheet.
glossary term picture Mortar 1 Mortar: A mixture of Portland cement or lime or a combination of both, sand, and water used to bind bricks, stones, and concrete masonry units together
glossary term picture Fiberglass 2 Fiberglass: Plastic that is reinforced with glass fibers. The fibers may be mixed randomly throughout the plastic, or come in the form of a flat sheet, or be woven into a fabric
3 Vapor barrier: A protective cover, commonly made of polyethylene, used for damp proofing walls and floors
glossary term picture Ridge Vent 4 Ridge vent: Ventilation opening in a sloped roof, installed at its pinnacle to remove moisture and warm air from the attic area

Cost to install spray foam insulation varies greatly by region (and even by zip code). To get free estimates from local contractors, please indicate yours.

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The information provided by our cost guides comes from a great variety of sources, including specialized publications and websites, cost studies, U.S. associations, reports from the U.S. government, contractors and subcontractors, material suppliers, material price services, and other vendor websites. For more information, read our Methodology and sources
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Cost to install spray foam insulation varies greatly by region (and even by zip code). To get free estimates from local contractors, please indicate yours.

The information provided by our cost guides comes from a great variety of sources, including specialized publications and websites, cost studies, U.S. associations, reports from the U.S. government, contractors and subcontractors, material suppliers, material price services, and other vendor websites. For more information, read our Methodology and sources