The short answer
Ask questions that produce documents, not reassurance: who will spray and what training they have, where the insulation boundary is, which exact product and minimum thickness, how moisture and drying are handled, how people and pets will be kept out and when you can safely return, what fire protection is required, how thickness will be verified, and what the itemized price excludes. The five answers that matter most are the boundary, the product, the moisture plan, occupant protection and what counts as a finished job.
Bring this checklist to the site survey and mark each answer verified, unclear or missing. A contractor unable to identify the exact product, installation limits, insulation boundary or occupant exclusion plan isn’t ready to quote a complex SPF job.
25 essential questions—and acceptable evidence
| # | Question | Evidence to request |
|---|---|---|
| 1 | What is your legal business name? | Identifiable company entity |
| 2 | Are you licensed where required? | Current authority record |
| 3 | What insurance do you carry? | Current certificates |
| 4 | Who will actually spray the foam? | Crew and supervisor identities |
| 5 | What training does the crew have? | Relevant verified credentials |
| 6 | Have you done this exact assembly? | Comparable project references |
| 7 | Have you inspected leaks and moisture? | Survey notes/photos |
| 8 | Where is the insulation boundary? | Sketch or assembly description |
| 9 | Why foam rather than cheaper alternatives? | Building-specific explanation |
| 10 | Open-cell or closed-cell—and why? | Design rationale |
| 11 | What exact product and manufacturer? | Technical/safety sheets |
| 12 | What minimum thickness is required? | Written specification |
| 13 | What R-value and code path apply? | Product plus assembly calculation |
| 14 | How is the air barrier continuous? | Transition/joint detail |
| 15 | What is the moisture/drying strategy? | Condensation/water-control explanation |
| 16 | Are existing vents changing? | Approved attic/crawl-space design |
| 17 | Which electrical/mechanical areas need protection? | Worksite plan |
| 18 | How will people and pets be excluded? | Written exclusion plan |
| 19 | What PPE and ventilation are used? | Site safety plan |
| 20 | When can we safely re-enter? | Product-specific cure/re-entry plan |
| 21 | What fire protection is required? | Code-accepted finish/detail |
| 22 | How will thickness/coverage be verified? | Inspection/photos |
| 23 | What’s the full price and board-foot scope? | Itemized proposal |
| 24 | What is excluded and what causes extras? | Written exclusions/change orders |
| 25 | How do warranty and defect repairs work? | Warranty and contact process |
The five answers that matter most
Where is the thermal boundary? Attic floor and roof deck are not interchangeable. A vented crawl-space floor and sealed foundation perimeter also differ.
What product will be installed? Demand a named manufacturer and data sheet, not just “premium foam”.
How will moisture be managed? The contractor should address roof leaks, foundation drainage and vapor behavior before spraying.
How are occupants protected? EPA recommends exclusion of unprotected people from application areas, worksite ventilation and specific re-entry instructions[1][2].
What counts as a finished job? Require acceptance criteria and photos before finishes conceal the insulation.
Questions about price and quantities
The checks that apply to any spray foam bid (credentials, product traceability, site assessment, safety plan, verification and an itemized all-in price) are set out in how to choose a spray foam contractor.
Questions about installer competency
The checks that apply to any spray foam bid (credentials, product traceability, site assessment, safety plan, verification and an itemized all-in price) are set out in how to choose a spray foam contractor.
What good and bad answers sound like
| Weak answer | Stronger answer |
|---|---|
| “Two inches is code everywhere” | “Here’s the climate/code pathway and product-specific depth for this assembly” |
| “It waterproofs the roof” | “Roof leaks must be fixed separately; this is the insulation and air-control design” |
| “Everyone can return tomorrow” | “Here’s the named product’s re-entry/ventilation procedure” |
| “It’s R-21, trust us” | “Here’s the product R-value and measured minimum installed thickness” |
| “We cover all problems” | “Here’s the workmanship warranty, exclusions, inspection and remedy process” |
| “You won’t need ventilation anymore” | “Here’s the post-retrofit whole-house ventilation and humidity assessment” |
Copy-and-send contractor quote request
Use this message to get comparable written offers:
I’m getting comparable quotes for insulation at [attic floor / roofline / exterior wall / basement / crawl space] in [city/ZIP]. Please inspect moisture and existing conditions, measure the treated surface, and specify your exact foam product, minimum depth, insulation/air barrier design, fire protection, worksite ventilation and product-specific re-entry instructions. Please include prep, removal, masking, labor, inspection, cleanup, warranties, exclusions, crew minimums and total price. If another insulation system offers better value, please explain it.
Include photos of the access points, known leaks and the existing insulation if available. Do not send personal information to an unverified lead broker.
How to score responses before signing
Score each of the five core areas—suitable assembly, proven qualifications, product/installation detail, occupant safety, and clear all-in contract—as pass or fail. Any failure needs resolving before award; this is a decision checklist, not an invented numerical contractor-quality score.
Use more competitive price comparison only among contractors who pass the essential technical and safety checks.
Questions owners ask
What should a foam estimate include?
Named product, treated area, depth, required protection, preparation, ventilation/re-entry procedure, inspection, cleanup, warranty and all costs.
What is the most important question?
Why is this particular foam assembly appropriate for the building's thermal, air and moisture requirements?
Sources
- Safer Workplace Practices for Spray Polyurethane Foam Installation, U.S. Environmental Protection Agency (archived). Accessed October 19, 2026. Last updated November 5, 2020; archived EPA page. PPE, isolation and ventilation for SPF work.
- Vacate and Safe Re-Entry Time for Spray Polyurethane Foam Application, U.S. Environmental Protection Agency (archived). Accessed October 19, 2026. Last updated September 2, 2020; archived EPA page.