Spray Foam Insulation Cost in the US (2026 Guide)
Spray foam is one of the most effective ways to insulate and air-seal an American home, but pricing varies by foam type, square footage, and access. Here’s a realistic 2026 cost breakdown.
Average spray foam prices
- Open-cell: $0.45–$0.75 per board foot (roughly $1.00–$1.50 per sq ft installed)
- Closed-cell: $1.00–$1.50 per board foot (roughly $2.00–$3.00 per sq ft installed)
- Typical attic (1,500 sq ft home): $2,500–$5,000
- Whole-home (walls + attic): $6,000–$15,000+
What affects the price?
Foam type (closed-cell costs more but adds structural rigidity and a moisture barrier), thickness (more depth = higher R-value = more material), and access (tight crawl spaces or steep roof pitches raise labor costs).
DIY vs professional
DIY kits ($150–$400) work for small sealing jobs. For attics, walls, and crawl spaces, hire a pro — correct thickness and even application matter for performance and code compliance.
Is it worth it?
Spray foam typically pays back through lower energy bills in 5–8 years and outperforms fiberglass on air sealing. Get at least three quotes from licensed contractors.