Spray Foam Insulation Cost
Our installed prices per square foot, per inch of foam, what typical jobs come to, and a calculator that prices your building in about a minute.
Estimated installed price
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Labor and material included. Areas are estimates; the free measure sets the exact price. Minimum job $1,500.
What typical jobs cost
| Job | Foam | Spray area | Installed price |
|---|---|---|---|
| Attic, 1,500 sq ft house | Open cell, 5.5" on the roof deck (about R-20) | 1,750 sq ft | $4,350 – $5,800 |
| 30×40 shop, 12 ft walls | Closed cell, 2" walls and roof (about R-13) | 3,100 sq ft | $7,750 – $10,850 |
| 40×60 barndominium, 14 ft walls | Closed cell, 2" walls, 3" roof (about R-13 / R-20) | 5,600 sq ft | $17,150 – $24,000 |
| Crawl space, 1,200 sq ft floor | Closed cell, 2" under the subfloor (about R-13) | 1,200 sq ft | $3,000 – $4,200 |
Labor and material included. Removing old insulation, coatings and long drives add to the price. Your exact number comes from a free measure.
How we price spray foam
Spray foam is priced by the square foot of surface we spray, times the inches of foam. Two inches of closed cell costs about twice as much per square foot as one inch. That makes it easy to compare quotes: ask every contractor for the foam type, thickness and square footage on each surface.
- Open cell
- $0.45–$0.60 per sq ft, per inch
- Closed cell
- $1.25–$1.75 per sq ft, per inch
- Old insulation removal
- $1.20–$1.60 per sq ft of floor
- Ignition barrier coating
- $0.75–$1.25 per sq ft
- Minimum job
- $1,500
Square footage means the surface we spray, not the floor area of the building. A roof deck is bigger than the floor under it because of the pitch, and a metal building’s spray area includes the walls, the roof and the gable ends.
What moves the price
- Foam type and thickness. Closed cell costs more per inch but needs fewer inches for the same R-value.
- Roof pitch. A steeper roof has more deck to spray over the same floor.
- Height and access. Tall walls and high roofs need lifts. Tight attics take longer.
- Prep. Buildings full of equipment or stored items take more masking.
- Old insulation removal. Priced per square foot of attic floor.
- Ignition barrier coating. Needed in some attics, crawl spaces and buildings where foam stays exposed.
- Job size. Small jobs have a minimum charge because setup costs the same.
Barndominium prices by size
| Size | Wall height | Spray area | Closed cell, 2" walls + 3" roof |
|---|---|---|---|
| 30×40 | 12 ft | 3,100 sq ft | $9,300 – $13,050 |
| 40×60 | 14 ft | 5,600 sq ft | $17,150 – $24,000 |
| 50×80 | 14 ft | 8,300 sq ft | $25,950 – $36,350 |
| 60×100 | 16 ft | 12,000 sq ft | $38,000 – $53,200 |
Spray area = walls + roof at a 4/12 pitch + gable ends, before doors and windows are taken out.
Spray foam compared with other insulation
Spray foam costs more than fiberglass batts or blown-in for the same R-value. What you pay for is the air seal and, with closed cell, the moisture control. In an attic with ductwork, foam on the roof deck does something blown-in can’t: it puts the ducts inside the house. On steel, foam is the only insulation that reliably stops condensation. In a vented attic with no ducts, blown-in on the floor is often the better buy, and we’ll tell you if that’s your situation.
Cost questions
How much does spray foam cost per square foot?
It depends on the foam and the thickness. Our installed rates per inch are listed above. Multiply by the inches you need: 5.5″ of open cell under a roof deck, or 2″ of closed cell on a metal wall, for example. The calculator does this for your building and adds removal or coatings if you need them.
Why is closed cell more expensive than open cell?
Closed cell uses about four times as much material per inch. It also gives almost twice the R-value per inch and blocks moisture, so you need fewer inches, and on steel it is the only foam that stops condensation.
Do you charge for the estimate?
No. The on-site measure and the written quote are free. The quote lists the foam type, thickness, R-value, square footage and price for each area.
Is the calculator price what I’ll pay?
It is a close range based on standard measurements. The free measure confirms the real surface area, the access and any prep, and your written quote will usually land inside the calculator range. If something on site changes the price, the quote explains why.
Can I spray part of the building now and the rest later?
Yes. Many shop and barndo owners do the roof first to stop the dripping and come back for the walls. We price each surface separately on the quote so you can choose.