Spray Foam Board-Feet and Set Count
Sizes spray foam in the board-feet and sets it is ordered by (a board-foot is one square foot one inch thick).
Example
You enter
- Area to spray (ft²) 2000
- Applied thickness (in) 3
- Board-feet per set (~4800 closed-cell) 4800
- Waste allowance (percent) 10
You get
- Board-feet 6000 bd-ft
- Foam sets to order 2
Details, formula, and sources
Board-feet = area x thickness; sets = ceil(bd-ft x (1 + waste) / set yield). 2,000 sf at 3 in of closed-cell is 6,000 board-feet, which on a 4,800 bd-ft set (with waste) is 2 sets; open-cell at a thicker 5.5 in still fits in 1 set because it yields far more. Temperature and substrate cut the field yield; the product set yield governs.
board_feet = area_sf x thickness_in; sets = ceil(board_feet x (1 + waste_pct/100) / yield_bd_ft_per_set).
Spray-foam board-feet identity by name (area x thickness gives board-feet; sets from board-feet over the per-set yield); first-principles arithmetic.
The board-feet arithmetic is public first-principles; the set yield comes from the product's rating.
Estimate. AHJ and licensed professional govern.
Field names used by the API: area_sf, thickness_in, yield_bd_ft_per_set, waste_pct, board_feet, sets
- Set yield ~4,800 board-feet for closed-cell, far more for open-cell; both less in the fieldSPF manufacturer
- Field factors temperature and substrate cut the yield below the rated valuefield conditions