What Influences Spray Foam Insulation Cost?
Spray foam installation is the most expensive type of insulation on the market. This elevated price is driven by 3 key factors:
- Chemical composition
- Effectiveness
- Popularity
What is Spray Foam Insulation Made Of?
Polyurethane spray foam insulation is created by combining two main components: isocyanate and polyol resin.
Isocyanates are highly reactive chemical compounds that are used in the creation of spray foam insulation, adhesives and protective coatings. Polyol resins are high-weight liquid resins that react strongly with isocyanates.
These 2 components mix at the tip of the spray gun. When they combine, their chemical reaction causes them to rapidly expand and create spray foam insulation.
What Makes Spray Foam Insulation So Effective?
The rapid expansion and high density of spray foam insulation makes it incredibly effective at insulating spaces with less material.It's also incredibly good at sealing air leaks.
For context: the thermal resistance of insulation is measured in R-value — the higher the R-value, the more effective the insulation. Texas homeowners need roughly ⅔ as much closed cell spray foam to achieve the same R-value as fiberglass batt insulation.
TABLE: Average Insulation Thickness Required to Achieve Home R-Value Standards
| Material (inches) | R-19 | R-25 | R-30 | R-38 | R-49 |
|---|---|---|---|---|---|
| Closed Cell Foam | 2 ¾” | 3 ¾” | 4 ¼” | 5 ½” | 7” |
| Open Cell Foam | 3 ½” | 5” | 6 ¾” | 8” | 10” |
| Blown In Cellulose | 3 ¾” | 5 ½” | 7” | 8 ½” | 10 ¾” |
| Fiberglass Batt | 4” | 5 ¾” | 7 ½” | 9 ½” | 11 ¾” |
Spray Foam Insulation is Popular but Expensive
"Spray foam is the best thing out there, but it is no small investment,” Cody Bridwell explains.
He’s not kidding — spray foam installation can cost 7-10 times as much as fiberglass batt installation. You’ll get extremely effective insulation in a much smaller area, but your upfront costs are substantially higher.
Open Cell vs. Closed Cell Spray Foam Cost
Spray foam insulation is divided into 2 distinct categories: open cell and closed cell.
- Open cell spray foam (OCF) is a type of insulation that consists of many small, open cells. Unlike closed cell foam, these cells are open and not filled with air, gas or liquid. As a result, open cell spray foam is cheaper and less dense than closed cell spray foam. Its R-value (insulation value per inch) isn't as strong as closed cell foam, but it's generally 1.8-2x better than fiberglass insulation.
- Closed cell spray foam (CCF) is made up of tiny, closed cells which are filled with gas (usually air). This composition gives closed cell spray foam a high insulation R-value compared to other types of insulation. Our research team found most closed cell insulation offers 2.5-3x better R-value than fiberglass batt insulation.
Texas residents pay $1.50-$2 more per board foot for closed cell spray foam than open cell foam insulation.
- Open Cell Spray Foam (OCF): average cost: $0.90 - $1.25 per board foot.
- Closed Cell Spray Foam (CCF): average cost: $2.50 - $3.25 per board foot.
What's a board foot? The cost of spray foam is measured by the board foot. A board foot is a measurement of volume that’s equivalent to one square foot of material applied one inch thick.
Spray Foam Cost vs. Other Insulation Types
Expect to pay between $2.20-$2.70 more per square foot for closed cell spray foam than fiberglass batt. Open cell spray foam costs between $0.65-$1.05 more per square foot than batt insulation.
Price differences between recycled cellulose and batt insulation are similar, although high-end recycled cellulose materials can be more expensive than fiberglass.
TABLE: National Insulation Material Cost Averages
| Insulation Material | Low Average Cost | High Average Cost | Unit |
|---|---|---|---|
| Closed Cell Spray Foam | $3.00 | $4.50 per | Per Board foot |
| Open Cell Spray Foam | $1.35 | $1.95 | Per Board foot |
| Blown In Cellulose | $0.50 | $1.80 | Per Square foot |
| Fiberglass Batt | $0.30 | $1.30 | Per Square foot |
Comparing Insulation Types: Spray Foam vs. Traditional Options
So how does spray foam stack up in real-world use compared to each insulation type?
"Without a doubt, spray foam is the best,” Bridwell states. “However, fiberglass remains a popular choice because it is cost-effective and hypoallergenic." He grades the insulation types as follows:
- Spray Foam: The highest R-value per inch, providing excellent thermal resistance.
- Fiberglass Insulation: Widely used and familiar to most homeowners - also called “blown in insulation.”
- Cellulose Insulation: Inexpensive, with a lower R-value per inch.
Between the 3 options, spray foam insulation performs significantly better, especially for attic insulation and wall insulation if you are replacing old insulation.
How to Use Spray Foam for Maximum ROI
If you’re spending more on spray foam insulation, treat it like any other premium investment. We asked Cody Bridwell how to maximize the return on your spray foam investment — where to install it in your home, how to optimize energy efficiency, and why DIY spray foam installation isn’t a good idea.
Where to Put Spray Foam in Your Home
Here’s where your home has the most leakage of air during the summer and winter months. 31% of air leakage comes from your home's floors, walls and ceiling. Windows, doors, and fireplaces account for an additional 35% of air leakage in a home.
Here are the areas we recommend you focus on:
- Attic and roof.
- Exterior walls
- Basem*nt or crawl space
- Around windows and doors
Energy Savings and Cost Efficiency
Proper insulation and air sealing can significantly reduce energy bills.
Bridwell notes, "Air seal plus insulation can save anywhere between 15% and 20% on your electric bill annually."
These savings are achieved by preventing air leaks — the equivalent leaving a window open year-round. Sealing these leaks ensures that your HVAC system operates more efficiently, reducing energy consumption and costs.
DIY Spray Foam Insulation Installation: Too Risky
Installing your own spray foam insulation isn’t recommended.
DIY spray foam installation comes with significant health risks. Installation requires respirators and full-body coverage to perform safely. DIY spray foam insulation shouldn't be attempted in an unventilated area due to the off-gassing of the chemicals.
Besides the health risks, improper installation of spray foam insulation is a waste of an expensive product. Not only does poorly fitted spray foam not achieve optimum R-value, the chemicals can destroy sections of your home.
“If spray foam is not fitted correctly, it can cause thousands of dollars in damage,” Bridwell explains.
