# How to Price Spray Foam Insulation Jobs (Per Board Foot)
Spray foam is one of the few insulation trades where a bad quote can wipe out the entire job's profit in a single afternoon. Chemical is expensive, sets vary in yield, and overspray you can't recover is money sprayed onto plastic. If you price by the square foot the way batt installers do, you will eventually lose your shirt on a tall-cavity or closed-cell job. The professionals who survive price by the board foot and back every number with real yield data from their own rig.
This guide walks through the actual math operators use to quote open-cell and closed-cell work, the cost drivers people forget, and the markup structure that keeps you solvent when chemical prices jump mid-season.
Board feet are the only unit that matters
A board foot is one square foot sprayed one inch thick. A 1,000 sq ft attic flat sprayed to 5.5 inches of open-cell is 5,500 board feet. That single conversion is the foundation of every honest spray foam quote, because your chemical cost scales with thickness, not floor area.
Work the takeoff this way:
- Open-cell (0.5 lb): measure the surface area, multiply by target inch thickness. Attics commonly run 5.5 to 7 inches; 2x4 walls at full-fill are 3.5 inches.
- Closed-cell (2.0 lb): same method, but you are usually chasing an R-value or a flash-and-batt depth (often 1 to 2 inches in walls, 2 to 3 inches in rim joists and roof decks).
Get your real-world yield per set, not the brochure number. A set (two 55-gallon drums, A-side and B-side) is rated around 16,000 board feet for open-cell and roughly 4,000 board feet for closed-cell. In the field you will see 12,000 to 14,000 open-cell and 3,200 to 3,800 closed-cell once you account for trim waste, picture-framing, off-ratio purges, and cold-substrate density gain. Use your worst recent jobs to set the planning yield, not your best.
Build your cost per board foot from the ground up
With a closed-cell set landing at roughly $1,800 to $2,400 delivered and a real yield of 3,500 board feet, your raw chemical cost is about $0.51 to $0.69 per board foot. Open-cell at $1,400 to $1,900 a set over 13,000 board feet runs $0.11 to $0.15 per board foot. Those are just the chemicals. Add:
- Labor: a two-person crew at $25 to $40/hr loaded, divided by the board feet they actually produce per hour (a good rig sprays 2,000 to 4,000 bf/hr of open-cell, far less in tight closed-cell cavities).
- Rig and equipment: proportioner, hose, and gun depreciation, plus diesel for the generator and compressor. Budget $0.03 to $0.06 per board foot.
- Consumables: suits, gloves, fresh-air respirator cartridges, masking plastic, tape. Easy to underbill at $75 to $200 per job.
- Mobilization: drive time, fuel, and setup. On residential, this is often 1 to 2 hours before a drop of foam hits the wall.
Most solid operators land their all-in cost around $0.18 to $0.28/bf for open-cell and $0.70 to $1.00/bf for closed-cell. Your sell price needs to clear that with room for overhead and profit.
Typical sell pricing (and where the margin lives)
Retail pricing tracks closely to these bands in most North American markets:
- Open-cell: $0.44 to $0.65 per board foot
- Closed-cell: $1.00 to $1.50 per board foot
- Flash-and-batt / hybrid: priced as the closed-cell flash plus a separate batt line
For whole-home or new-construction work, expect to discount toward the low end on volume. For retrofits, rim joists, crawlspaces, and any job where you are crawling on your belly through a 24-inch access, price toward the top. A 1,500 sq ft crawlspace closed-cell at 2 inches is 3,000 bf; at $1.25 that is a $3,750 job, and the access difficulty alone justifies it.
Apply a minimum job charge of $1,200 to $1,800. Mobilizing a rig, off-gassing a set's worth of purge, and burning a half-day for a single rim joist is a money-loser at hourly math, and small jobs are where new operators bleed.
The cost drivers beginners forget
Off-ratio waste. Cold drums spray off-ratio until they warm. Every purge into a trash bag is chemical you paid for and can't sell. Heated hose and proper drum conditioning protect your yield more than any pricing trick.
Substrate temperature. Closed-cell foam sprayed below 50F on a cold wall loses thickness and adhesion. You either heat the space (added cost) or you reschedule. Build a weather contingency into shoulder-season quotes.
Re-spray and trimming. Open-cell overfills the cavity and must be trimmed flush before drywall. That trim is labor and disposed waste. Closed-cell that exotherms too hot can scorch and require cut-out.
Disposal and PPE compliance. Empty drums, used cartridges, and overspray plastic have disposal cost. And the OSHA/NFPA side is not optional: respiratory protection, ventilation, and re-occupancy timing (typically 24 hours for open-cell, longer per manufacturer) are real line items and real liability. Document them.
A clean quoting workflow
1. Measure surface area by assembly (attic flat, roof deck, walls, rim, crawl) and assign a target inch thickness to each. 2. Convert to board feet per assembly and total the job. 3. Apply your set yield to get sets required, then round up to whole sets you'll actually open. 4. Cost it: chemical + labor + rig + consumables + mobilization. 5. Apply markup to hit your target gross margin (aim 45 to 55 percent gross on the all-in cost). 6. Add minimum-job and difficulty adjustments. 7. Quote a single number to the customer, but keep the board-foot breakdown for yourself.
Doing this on the back of an envelope works once. Doing it across 30 jobs a season, while tracking which chemical lots and which crews actually hit yield, is where a spreadsheet earns its keep. The Spray Foam Insulation Installation Toolkit runs the R-value and board-foot math by cavity, logs A-side/B-side ratios and cure conditions for each job, keeps the OSHA respiratory and ventilation inspection log, and rolls material cost, equipment hours, and labor into a per-job P&L so you can see which jobs actually made money.
Mistakes that cost real money
- Quoting per square foot of floor. Ignores thickness and crushes margin on tall cavities.
- Using brochure yield. Field yield is always lower; plan for your worst, not your best.
- Eating chemical price swings. Isocyanate and polyol prices move. Re-quote stale estimates older than 30 days.
- No minimum charge. Small jobs at proportional pricing lose money every time.
- Forgetting re-occupancy and ventilation time in the schedule, then rushing cure and creating a callback.
If you want the underlying method and a worked example before you commit to a workbook, the free starter guide and course walk through a sample attic and crawlspace quote step by step. Price by the board foot, protect your yield, and never let a cold drum or a forgotten minimum charge turn a full day's work into a wash.