10 Questions to Ask Before You Hire a Spray Foam Crew

Spray foam is a chemistry-dependent product installed on-site, which means the skill and diligence of the crew matters as much as the material itself. Two crews using the same foam brand can produce very different results depending on equipment calibration, experience, and attention to detail. Before signing a contract, walk through these questions with any contractor you are considering.

How Do You Check Mix Ratio and Quality During the Job?

Spray foam is created by combining two chemical components in a precise ratio at the spray gun. If that ratio drifts even modestly off-spec, the resulting foam can under-perform on R-value, cure improperly, shrink, or continue off-gassing longer than it should. Ask the contractor what equipment they use to monitor mix ratio in real time, and whether their rig has ratio-check or logging capability. A contractor who can answer this specifically and confidently is signaling real technical competence. A contractor who seems unfamiliar with the question at all is a meaningful yellow flag.

What Warranty Do You Provide, and What Does It Actually Cover?

Ask for warranty terms in writing, not just a verbal assurance. Clarify whether the warranty covers workmanship (the installation itself) versus material defects (covered separately by the foam manufacturer), how many years each portion runs, and what would void the warranty. Also ask what the actual remedy process looks like if a problem shows up two or three years down the road — who do you call, and what is their typical response time on warranty issues.

What Exactly Is Included in the Written Scope of Work?

Get a detailed, itemized scope before work begins, not just a total price. The scope should specify which areas of the home are being treated, what foam type and thickness or R-value target is planned for each area, whether removal of existing insulation is included, and whether any air sealing, baffle installation, or fire/ignition barrier coating is part of the job. A vague scope is one of the most common sources of disputes after the work is done.

What Type of Rig and Equipment Do You Use?

Spray foam equipment ranges from smaller portable units to full truck-mounted proportioning rigs. Ask what equipment the crew will be using for your specific job and whether it is properly calibrated and maintained on a regular schedule. Equipment condition directly affects mix-ratio accuracy and spray consistency, so a contractor who takes equipment maintenance seriously is generally a good sign.

Is Your Crew Certified, and By Whom?

Ask whether the specific technicians who will be on-site (not just the company as a whole) hold any manufacturer or industry training or certification. Certification programs exist through several foam manufacturers and industry associations and typically cover safe handling, application technique, and building-science fundamentals. Certification alone does not guarantee a great outcome, but its absence combined with vague answers to your other questions is worth weighing carefully.

What Is the Timeline, Including Cure and Re-Entry Time?

Ask how long the job itself will take, and just as importantly, how long you and your family (and pets) need to stay out of the treated area after spraying before re-entry is safe. Re-entry time varies by foam type and application, and a professional crew should give you a specific timeframe rather than a vague "should be fine by tomorrow." Also ask about full cure time versus re-entry time, since these are not always the same thing.

Who Handles Cleanup, and What Does That Include?

Spray foam overspray, plastic sheeting used to protect surrounding surfaces, and any removed old insulation all need to be dealt with after the job. Confirm in advance whether cleanup and disposal are included in the quoted price or billed separately, and what "cleanup" specifically means — full removal of protective materials and debris, or just the foam application itself with the rest left to you.

Can You Provide References or Photos From Past Projects?

Ask for examples of similar past projects — ideally photos of comparable spaces (attic, crawlspace, whatever matches your job) and, where possible, contact information for past customers willing to speak about their experience. A contractor with a real track record should have no hesitation providing this.

How Do You Handle Ventilation and Code Requirements?

Certain attic and roofline applications have specific code requirements around baffles for ventilation or ignition/thermal barrier coatings over exposed foam in living or storage areas. Ask directly whether your project has any such requirements and how the contractor plans to meet them. This question also serves as a useful check on how thoroughly the contractor has actually assessed your specific space.

What Happens If Something Goes Wrong Mid-Job?

Ask how the contractor handles surprises discovered once work is underway — for example, finding rotted framing, unexpected moisture, or wiring that was not visible during the initial walkthrough. A contractor with a clear, calm answer about how they pause, communicate, and adjust scope if needed is more trustworthy than one who insists nothing like that ever comes up.

Putting It Together

No single answer to any one of these questions should make or break a hiring decision on its own, but the pattern across all of them tells you a lot. A contractor who answers specifically, provides documentation without being pushed, and is transparent about process and limitations is generally a safer choice than one who answers vaguely, avoids specifics, or seems annoyed by the questions. Spray foam is a significant, largely irreversible investment in your home — a short conversation covering these ten questions upfront is a small amount of effort relative to the value of getting the right crew for the job.