How much does it cost to spray foam for 1000 square feet?

Cost to spray foam 1000 square feet depends on whether you mean 1000 square feet of area to be insulated and type of foam and thickness. For open cell spray foam, which is cheaper and used for interior walls and attics, installed cost is typically $1.00 to $2.50 per square foot for 3.5 inch thickness, so 1000 square feet would cost $1000 to $2500. For closed cell spray foam, which provides higher R-value per inch, moisture barrier, and structural strength, installed cost is typically $2.00 to $4.50 per square foot for 2 inch thickness, so 1000 square feet would cost $2000 to $4500. If you mean insulating attic floor of 1000 square foot house with 6 inches open cell to reach R-20, cost might be $1500 to $3000. If insulating walls of 1000 square foot area, cost may be higher due to labor. DIY spray foam kits cost around $350 to $800 per 200 to 600 board feet, so for 1000 square feet at 3 inches thick you need 3000 board feet, costing $2000 to $3500 in material alone. Prices vary by region and contractor.