How to Price a Spray Foam Insulation Job | Reddit & LinkedIn

Foam is priced by the board foot, which is one square foot at one inch of thickness. To quote, multiply the area by the applied thickness the job needs to hit its target R-value. A wall foamed to three inches of closed cell has three board feet per square foot. Quoting by board feet, rather than a flat per-square-foot rate, is what keeps you from losing money when a job needs more thickness than a quick eyeball suggested.

Open cell foam is lighter, cheaper per board foot, expands more, and is common for interior walls and sound control. Closed cell is denser, delivers a higher R-value per inch, and acts as an air and moisture barrier, which makes it the choice for rim joists, crawlspaces, and exterior applications. Closed cell costs roughly two to three times open cell per board foot. Quote the cell type as its own line so the client understands why the number moves with the product, not just the area.

Open cell runs about $0.45 to $0.75 per board foot installed in 2026, and closed cell runs $1.00 to $1.75 per board foot. On a per-square-foot basis, an attic or wall assembly commonly lands at $1.50 to $4.50 depending on thickness and cell type. A full attic or whole-home foam job can run several thousand dollars. Price from board feet, cell type, prep, and rig time, since two jobs of the same square footage can differ widely by thickness.

Foam is a spray product, so prep is real labor. Masking windows and finishes, setting containment, and protecting HVAC from overspray all take time. Removing old, wet, or rodent-damaged insulation is a separate line. Ventilation and re-entry time matter too, because occupants should stay out until the foam cures and the space is aired. Naming these lines shows the client a professional scope and keeps a rushed, under-masked job from becoming an expensive cleanup.

ContractShield lets you save foam templates for open cell and closed cell with your per-board-foot cost, prep rates, and rig time, so a new quote is a quick edit from the area and target thickness. Enter the numbers, add prep, and send an itemized, signable estimate the same day. You run the job and invoice on milestones for a flat 2% per job (1% each side), capped at $250, no per-lead fees.

Target R-value drives thickness, and thickness drives board feet and price, so tie the quote to the code requirement for the assembly. An attic, a wall, and a rim joist each have a different code R-value, and hitting it with closed cell takes fewer inches than open cell. State the target R-value and resulting thickness on the quote so the client sees you are pricing to code, not just spraying a set depth. It also protects you if an inspector or energy rater checks the assembly later.