How to compare spray foam insulation quotes, line by line (October 2026)
Prices, rules and sources checked October 22, 2026.
Comparing spray foam quotes is a units problem before it is a price problem. One installer prices by the square foot, another by the job, a third by the board foot, and each may spray a different thickness. Put every bid on the same footing (price per board foot, inches against R-value, and the same list of extras), and the real differences show.
This page walks through that conversion with Angi's 2026 installed rates, $0.60 to $3.10 per board foot, and the thickness and R-value figures we use site-wide. If you have one bid and want a quick read on it, the quote checker does the math for you. If you have no bid yet, start with the spray foam cost calculator.
Step 1: get the same five facts on every bid
HomeGuide's advice is to ask for "a detailed quote including areas to be sprayed, estimated R-value, insulation depth or thickness, and spray foam brand and type." Those five facts are what make two bids comparable. A bid that gives only a lump sum and "spray foam attic" can't be checked.
| Line on the bid | What to look for | Why it matters |
|---|---|---|
| Area and square feet | Each surface listed separately: roof deck, gable walls, rim joists, crawl walls | HomeGuide notes the sprayed surface "differs significantly from the floor square footage." A sloped roof deck has more area than the attic floor under it |
| Open-cell or closed-cell | One named type per area, not "foam" | Closed-cell runs $1.30 to $3.10 per board foot installed against $0.60 to $1.60 for open-cell (Angi) |
| Brand and product | Manufacturer and product name | The R-value per inch comes from the product's own data, and the FTC's contractor guide asks for each product's brand in the contract |
| Thickness in inches | A number of inches for each area | Board feet scale directly with inches: 6 inches of foam is twice the material of 3 |
| R-value | An R-value for each area, matching the inches | Check it against the table in Step 3. Rebate rules are written in R-values: Colorado Springs Utilities, for one, requires R-49 in attics, R-13 in exterior walls and R-15 continuous on crawl space walls |
Sources: HomeGuide, "How Much Does Spray Foam Insulation Cost? (2026)" (Dec 1, 2025); Angi, "How Much Does Spray Foam Insulation Cost? [2026 Data]" (updated Sep 9, 2026); FTC, Hiring a Contractor (March 2014, via GovInfo); Colorado Springs Utilities, Insulation & air sealing rebate.
Step 2: turn every bid into price per board foot
A board foot is one square foot of foam one inch thick. Square feet times inches gives board feet; the bid price divided by board feet gives a price you can set beside Angi's range and beside the other bids.
| Job | Board feet | R-value by our arithmetic | Angi range at those board feet | HomeGuide per sq ft, same area |
|---|---|---|---|---|
| 1,200 sq ft roof deck, open-cell, 6 inches | 7,200 | About R-21.6 | $4,320 to $11,520 | $1,800 to $4,200 |
| 1,200 sq ft roof deck, closed-cell, 3 inches | 3,600 | About R-20.4 to R-21.3 | $4,680 to $11,160 | $3,600 to $6,000 |
| 1,000 sq ft of open stud walls, open-cell, 3.5 inches | 3,500 | About R-12.6 | $2,100 to $5,600 | $1,500 to $3,500 |
| 1,000 sq ft of open stud walls, closed-cell, 2 inches | 2,000 | About R-13.6 to R-14.2 | $2,600 to $6,200 | $3,000 to $5,000 |
The two guides disagree, and the table shows why you should prefer board feet. HomeGuide's per-square-foot rates ($1.50 to $3.50 open-cell, $3.00 to $5.00 closed-cell) do not state a thickness, so they can't tell a 3-inch job from a 6-inch one. Board feet can.
An example with made-up numbers, not a real quote: a $9,000 bid for 1,200 square feet of open-cell at 6 inches is 7,200 board feet, or $1.25 per board foot, inside Angi's open-cell band. Suppose a second bid asks $9,000 for "R-38 closed-cell" on the same deck and gives no inches. At R-6.8 to R-7.1 per inch, R-38 takes about 5.4 to 5.6 inches, or 6,420 to 6,710 board feet, which works out to $1.34 to $1.40 per board foot, close to the bottom of Angi's closed-cell band. Before you accept that bid, ask it to state the inches it will spray.
Sources: Angi, "How Much Does Spray Foam Insulation Cost? [2026 Data]" (updated Sep 9, 2026); HomeGuide, "How Much Does Spray Foam Insulation Cost? (2026)" (Dec 1, 2025); Profoam product price sheet (R-value per inch and typical depths).
Step 3: check the inches against the R-value
We use R-3.6 per inch for open-cell and R-6.8 to R-7.1 for closed-cell, from the Profoam product sheet. Your installer's product may differ a little, which is why the brand matters.
| R-value on the bid | Open-cell inches | Closed-cell inches |
|---|---|---|
| R-13 | 3.6 | 1.8 to 1.9 |
| R-19 | 5.3 | 2.7 to 2.8 |
| R-30 | 8.3 | 4.2 to 4.4 |
| R-38 | 10.6 | 5.4 to 5.6 |
| R-49 | 13.6 | 6.9 to 7.2 |
The receipt you get after the job follows a stricter rule than our arithmetic. The FTC R-value Rule tells installers to figure R-value from "the data that the manufacturer gives you" and says "Do not multiply the R-value for one inch by the number of inches you installed." The receipt must show "the coverage area, thickness, and R-value," be "dated and signed by the installer," and list each part of the house separately, without adding up coverage areas or R-values across them. If a quote promises an R-value, ask to see the receipt format it will use.
Sources: Profoam product price sheet (R-value per inch and typical depths); eCFR, 16 CFR 460.17, What installers must tell their customers (FTC R-value Rule, as amended at 84 FR 20790, May 13, 2019).
Step 4: find the extras that one bid includes and another leaves out
Two bids at the same price per board foot can still be different jobs. These lines are easy to leave off a bid, so ask about each one.
| Extra | Published price | Source |
|---|---|---|
| Removing old insulation | $1.00 to $2.50 per sq ft | HomeGuide |
| Vapor barrier where open-cell needs one | $0.65 to $1.00 per sq ft | Angi |
| Mold remediation before spraying | $1,125 to $3,345 | Angi |
| Minimum job charge | $1,000 to $2,000 or more | HomeGuide |
| Labor, when quoted separately | $50 to $100 an hour, or $0.44 to $3.30 per sq ft | Angi |
| Thermal or ignition barrier | No published national rate found; ask for it as its own line | Unknown |
The barrier line deserves the most attention. DOE's Building America Solution Center explains that "most codes require a thermal barrier (typically ½-in. gypsum board or equivalent) or an ignition barrier (typically ⅜-in. gypsum board or equivalent) over foam insulation," though some foam products are tested to reduce or remove that need. A bid that sprays foam in an attic or crawl space and says nothing about a barrier or a tested coating leaves you to find out at inspection. Our DIY kits vs hiring a pro page quotes the code exception for attics entered only for repairs.
Old-home work costs more per square foot. Angi puts new builds at $1 to $4 per square foot and existing homes at $3 to $5, because existing homes add opening walls, removal and new drywall. If one bid assumes open studs and another assumes closed walls, they are pricing different work.
Sources: HomeGuide, "How Much Does Spray Foam Insulation Cost? (2026)" (Dec 1, 2025); Angi, "How Much Does Spray Foam Insulation Cost? [2026 Data]" (updated Sep 9, 2026); DOE/PNNL Building America Solution Center, Unvented, Insulated Crawlspaces (code notes on foam plastics).
Step 5: read the contract terms, not just the price
The FTC's contractor guide lists what a home improvement contract should hold. For a spray foam job, these items matter most:
- Who is doing the work. The FTC says to consider "only contractors who are licensed and insured" and to confirm the license with your state or county and ask for proof of insurance. Licensing rules differ by state; several of our state hubs note the rules we verified.
- Materials by brand. "a detailed list of all materials including each product's color, model, size, and brand."
- Warranties in writing. Who honors them, the contractor or the manufacturer, how long they run and their limits. HomeGuide also suggests asking for "a foam removal guarantee in the event of incorrect installation."
- Permits and cleanup. The contract should state the contractor's obligation to get permits; the FTC lists "Scammers ask you to get any required building permits" as a warning sign. The FTC also suggests a "broom clause" that makes the contractor responsible for all clean-up work.
- Payments. "Don't pay the full amount for the project up front," and tie payments to completed work. Some states cap down payments; your state consumer agency can tell you the limit.
- Re-entry time. EPA's client checklist says "Some manufacturers recommend 24 hours after application" before residents move back in, "but the recommended time may vary." Angi says to stay out for at least 24 to 72 hours. Ask the installer for the product's own re-occupancy time in writing.
- Rebate paperwork. HomeGuide's list of questions includes "Are there rebates available, and do you apply for them?" Check the answer against our 2026 insulation rebate tracker; some utilities only pay through enrolled contractors (TVA EnergyRight, for one, requires its Quality Contractor Network), and the federal 25C credit ended for work placed in service after December 31, 2025. Our grants vs rebates guide covers what is left.
If you sign at your kitchen table, the FTC Cooling-Off Rule can apply. It covers sales of "$25 or more if the sale is made at the buyer's residence" (or $130 or more at other places away from the seller's business, such as a hotel room), and the seller must give you a notice that you "may cancel this transaction at any time prior to midnight of the third business day." Some sales are excluded, including ones conducted entirely by mail or phone.
Sources: FTC, How To Avoid a Home Improvement Scam (July 2022); FTC, Hiring a Contractor (March 2014, via GovInfo); HomeGuide, "How Much Does Spray Foam Insulation Cost? (2026)" (Dec 1, 2025); Angi, "How Much Does Spray Foam Insulation Cost? [2026 Data]" (updated Sep 9, 2026); EPA Safer Choice, Client Checklist for High-Pressure, Two-Component Spray Polyurethane Foam (SPF) Insulation; TVA EnergyRight, Residential Rebates; IRS, Energy Efficient Home Improvement Credit; eCFR, 16 CFR Part 429, Cooling-Off Rule (thresholds as amended at 80 FR 1332, Jan. 9, 2015; effective Mar. 13, 2015 per the Federal Register).
Red flags in a spray foam bid
- No inches anywhere, only "R-38" or "full coverage."
- One lump sum for several areas with no square footage per area.
- "Foam" with no open-cell or closed-cell named, or no brand.
- No word on removal of old insulation when you have some.
- No thermal or ignition barrier line for exposed foam.
- Pressure to sign today, cash only, or full payment up front. The FTC lists each of these as a sign of a scam.
Sources: FTC, How To Avoid a Home Improvement Scam (July 2022).
Where to go from here
Not sure which foam a bid should use? Our open-cell vs closed-cell comparison covers where each belongs, and spray foam vs fiberglass vs cellulose shows when a cheaper fiber insulation is the better buy. Getting crawl space bids? The best insulation for crawl spaces ranks the options and their published prices. Our metro cost pages price sample jobs at local code levels: Phoenix, Tucson, Atlanta, Houston, Tampa, Nashville, Colorado Springs, Huntsville, Tulsa, Omaha.
Want more bids to compare? The form below passes your project to up to three partner installers who serve your area. Run each bid you get through the quote checker.
Comparing spray foam quotes: FAQ
What should a spray foam quote include?
At minimum: each area to be sprayed with its square footage, open-cell or closed-cell, the foam brand, the thickness in inches and the R-value. HomeGuide asks for "areas to be sprayed, estimated R-value, insulation depth or thickness, and spray foam brand and type." Also get removal of old insulation, any thermal or ignition barrier, and the payment schedule in writing.
How do I compare two spray foam bids that use different units?
Convert both to price per board foot. Multiply the sprayed square feet by the thickness in inches to get board feet, then divide the price by that number. Angi's 2026 installed range is $0.60 to $1.60 per board foot for open-cell and $1.30 to $3.10 for closed-cell.
Is the cheapest spray foam quote the best one?
Not automatically. The FTC says "Don't automatically choose the lowest bidder" and to ask for an explanation if there is a big difference among the estimates. A low bid that is thinner, leaves out removal or skips a required barrier is not the same job.
What does the installer have to give me after the job?
Under the FTC R-value Rule (16 CFR 460.17), the installer must give you a dated, signed contract or receipt showing the coverage area, thickness and R-value of the insulation installed, figured from the manufacturer's data, with each part of the house listed separately.
Can I cancel a spray foam contract I signed at home?
It can be possible. The FTC Cooling-Off Rule covers many sales of $25 or more made at your home, and the seller must tell you that you may cancel until midnight of the third business day. Some sales are excluded, so read the cancellation notice the seller hands you.