What Actually Affects the Price of a Spray Foam Quote

Spray foam is priced by the board foot — one square foot of coverage at one inch thick. So the biggest driver of your quote is simply how much area you're covering and how thick you're spraying it. A 2-inch closed-cell application costs roughly twice what a 1-inch application costs on the same wall, because it uses twice the material. That sounds obvious, but a surprising number of quotes bury the thickness and only show a lump-sum price.

The second driver is foam type. Closed-cell costs more per board foot than open-cell because the chemistry is more expensive and it's denser. But closed-cell also gives you nearly double the R-value per inch and a vapor barrier, so you often need less of it to hit the same performance. A cheap open-cell quote can end up costing more than closed-cell once you thicken it to reach code R-value. Always compare cost-per-R, not cost-per-inch.

The third driver is prep and access. A clean, open wall at the right temperature is fast to spray. A cramped crawlspace with pipes, a roof deck that needs masking, or a surface that needs cleaning and drying all add labor hours. If your quote is high, ask whether the cost is material or labor — labor-heavy quotes usually mean difficult access, not a greedy contractor.

The fourth — and the one most cheap quotes skip — is code compliance. Spray foam exposed in an occupied space needs a thermal barrier (drywall) or an approved intumescent coating. A quote that leaves this out will look great until the inspector makes you fix it, at which point you're paying for it twice. A proper quote lists the barrier as a line item.

Finally, equipment and calibration matter to price indirectly. A contractor who calibrates their rig, uses certified material, and carries WSIB and liability insurance has higher overhead than someone working out of a pickup. That overhead is what makes the foam actually last. The cheapest quote is rarely the cheapest project.