The short answer
Spray foam is priced by the square foot and the thickness, measured in inches or board feet. As a typical estimate, open-cell foam often falls around $1 to $2 per square foot at common attic depths. Closed-cell foam often falls around $1.50 to $3+ per square foot for a couple of inches. These are rough ranges, not quotes. Real prices vary by contractor, materials and the job.
What drives the price
- Foam type: closed-cell uses more material per inch
- Thickness and R-value target
- Square footage and roof pitch
- Removing old insulation
- Access: tight attics, crawl spaces and multi-story homes
- Prep work like air sealing, baffles or a thermal barrier
Typical project ranges (estimates)
A full attic roof deck in an average-size North Texas home often lands in the low-to-mid thousands. Crawl spaces and rim joists are usually smaller jobs. Metal buildings are typically priced by wall and roof square footage.
Getting an accurate number
The only reliable price is an on-site or measured estimate. Ask each installer for the foam type, thickness, R-value, square footage and what prep is included, so you can compare quotes fairly. Call (469) 812-8909 for a free estimate in the Princeton area.