Let’s get down to what everyone wants to know. How much does spray foam insulation cost? Short answer: about 3x – 4x the cost of fiberglass insulation. But, spray polyurethane foam does something that standard fiberglass doesn’t do, and that’s provide a continuous air barrier. Keep in mind that the prices below are budgetary, and will vary job-to-job. Also, we’re located in Kingsport, Tennessee, and primarily serve the eastern Tennessee, southwestern Virginia, eastern Kentucky, and western North Carolina markets. Prices may vary by region.
Follow the three steps below and you should have an accurate budget for your project!
Step 1: Figure out what you need— determine the type of spray foam and applied thickness
How much foam do you want? Remember: there are two main types of spray foam insulation— open cell and closed cell. Generally speaking, open cell foam is used above grade in residential applications (rooflines, attic floors, exterior walls, soundproofing). Closed cell is popular below grade in residential applications (crawl spaces, basements), and in many commercial and industrial settings. You’ll also see closed cell sprayed where a high R-value is required at a minimum thickness. Here’s a table we put together from an earlier blog post (Open Cell vs. Closed Cell Spray Foam Insulation). Note the R-value per inch of each type of foam, and where you’ll be applying it.
Step 2: Calculate board footage
We can determine a price with some quick math. Spray polyurethane foam is typically calculated by the board foot, which is 12” wide x 12” long x 1” thick.
A quick way to calculate your board footage is to take the square footage of space you want to spray and multiply it by the applied depth in inches (sq. ft. x depth in inches = board feet).
Let’s look at an example: take an above grade wall that is 50’ in length and 10’ tall (50’x10’). It is framed on 2’x4’ wood studs, so each wall cavity is 3-1/2” in depth. Because it’s an above grade wood-framed wall, you’ll probably want to spray open cell (light density, 0.5 lb) foam to the full thickness of the stud.
To calculate board footage, multiply 50 x 10 x 3.5 = 1,750 board feet (bd ft).
The same process applies to closed cell (medium density, 2.0 lb) foam.
Step 3: Board Feet x Price Per Board Foot
There are several factors that play into how a job is priced, including how much prep is required, how much foam will be sprayed, how difficult the job is from a labor perspective, and how far we’ll need to travel.
Open cell spray foam: $0.25 – $0.50 per board foot
Closed cell spray foam: $0.90 – $1.50 per board foot
So, from the example in Step 2: 1,750 bd ft x $0.50 per bd ft = $875.00
It’s that simple!
If your job is small, choose a board foot price on the higher end of the spectrum. If you have a new house or major remodel, pick a number on the lower end of the spectrum. If you’re looking to finish a basement or bonus room, pick a number somewhere in the middle.
I should also note that there are some jobs too small for us to do within these price ranges.
Hopefully this three step guide has been useful in applying a general budget to your upcoming project. If you have any questions, don’t hesitate to Contact Us.