Questions to ask
1. Are you licensed (if your state or city requires it) and can you show general liability insurance and workers’ compensation?
Why it matters: Insulation work often means attic crawling, ladder work, cutting around wiring and recessed lights, and hauling bags of material. Ask for a certificate of insurance naming your address for the job dates, liability limits, and workers’ comp if they have employees. Uninsured fall or fire damage from mishandled fixtures becomes your problem. “We’re bonded” is not the same as liability coverage — get carrier name, policy number, and dates in writing before work starts.
2. What insulation type do you recommend for each area — blown-in (cellulose or fiberglass), batts, rigid foam, or spray foam — and why for my house and climate?
Why it matters: Attics, walls, and crawl spaces often need different products. Blown cellulose or fiberglass suits many open attics; batts need careful fitting; closed- or open-cell spray foam air-seals but costs more and needs dry, compatible substrates. Ask how climate zone, existing insulation, budget, and access drive the choice. A one-product pitch for every house (“we only do foam”) may ignore a better, cheaper fit. Get product brand, density or bag count, and installed R-value per area in the written quote.
3. What target R-value will you install in the attic, walls, and floors — and does that match local code or DOE climate-zone guidance?
Why it matters: R-value is the resistance to heat flow; under-insulating saves little on the bill and leaves comfort gaps. Ask for the installed R-value (not just “we’ll add some”), whether they account for existing material, and how depth or inches of blown-in translate to R for the product they use. Compare their numbers to your climate zone recommendations and permit requirements. Vague “enough to make it warmer” without numbers is a red flag.
4. Will you air-seal before insulating — attic bypasses, top plates, chases, recessed lights, and duct penetrations — and is that included in the price?
Why it matters: Insulation without air sealing often underperforms; heated air leaks into the attic or outdoors. Ask whether they caulk or foam gaps, seal around flues with fire-safe materials, and protect or box IC-rated vs non-IC fixtures per manufacturer rules. Confirm air sealing is a line item, not an optional upsell after a low “blow only” bid. Skipping sealing is a common way cheap attic jobs disappoint.
5. How will you handle vapor barriers, attic ventilation, and moisture — especially if spray foam or dense-pack walls are involved?
Why it matters: Wrong vapor-control layers or blocked soffit vents can trap moisture and encourage mold. Ask whether ridge and soffit vents stay clear (baffles/chutes for blown attic insulation), how they treat cathedral ceilings, and whether a vapor retarder is recommended for your climate and wall assembly. For spray foam, ask about ignition barriers or thermal barriers where codes require them, and whether framing must be dry before application. Moisture problems after insulation are expensive to reverse.
6. Will you inspect for old vermiculite, suspected asbestos, or mold before disturbing attic or wall cavities — and what happens if you find them?
Why it matters: Some older attics contain vermiculite that may contain asbestos (e.g., historic Zonolite-era material). Disturbing it without testing and proper abatement can contaminate the home. Ask whether they look for vermiculite or crumbling pipe wrap before blowing new material, whether they require third-party testing, and who pays if work stops. Active mold or wet insulation should be addressed with remediation and dry-out — not covered over. “We’ll just blow over whatever is there” is not acceptable when hazardous materials are possible.
7. What is the written scope — rooms and assemblies, remove vs add over existing, square footage or bag counts, and what is excluded?
Why it matters: Phone quotes based on “insulate the attic” hide walls, knee walls, rim joists, crawl spaces, and whether old batts are removed. Ask for a written plan: areas included, target R-value, product, whether existing insulation is removed or topped, access points, and exclusions (electrical upgrades, mold remediation, asbestos). Clarify change-order rules if cavities are blocked or wet. The cheapest lump sum often grows once “extra areas” appear mid-job.
8. Who pulls permits if required, and will electrical clearances (recessed lights, knob-and-tube, junction boxes) be handled safely?
Why it matters: Some jurisdictions require permits for insulation or energy upgrades. Covering knob-and-tube or non-IC fixtures incorrectly is a fire hazard. Ask who obtains permits and inspections, how they treat old wiring, and whether an electrician must upgrade fixtures first. Get that sequence in writing. Crews that ignore electrical clearances to finish fast create liability you may not see until an insurance claim.
9. What warranty covers materials and workmanship — settling of blown-in, foam adhesion, and who re-services if R-value or coverage fails inspection?
Why it matters: Blown insulation can settle; foam can shrink or miss coverage in corners. Ask for manufacturer material warranty terms and the contractor’s workmanship period, what “coverage” means (depth checks, infrared or visual), and whether they return at no charge if an inspector finds voids. Get warranty contacts in writing. Lifetime marketing language with fine print that voids for “any settling” is weak protection.
10. What cleanup is included — attic floor protection, bag and scrap removal, HVAC filter or register care, and living-space dust control?
Why it matters: Fiberglass and cellulose dust spreads easily. Ask how they contain work areas, protect stored items, remove empty bags and scraps, and whether attic access and living spaces are vacuumed. Confirm dump fees are included. “Homeowner sweeps the attic” after a blow job is a common surprise. For spray foam, ask about overspray protection and odor/ventilation timelines before reoccupying rooms.
11. Can you provide recent local references for similar jobs, and is payment tied to milestones rather than a large cash-only deposit up front?
Why it matters: References from homes with comparable scope (attic blow, wall dense-pack, spray foam rim joists) beat star ratings alone. Ask for two recent clients, how long the company has operated locally, and a payment schedule tied to material delivery, completion, and final walkthrough or inspection. Large cash-only demands before work, or pressure to “sign today for rebate deadlines” without a written scope, are classic high-pressure tactics. Legitimate firms usually invoice under a business name and accept card or electronic payment.
Red flags
- No insurance proof, or refuses licensing info where your area requires contractor credentials.
- Cannot name product, installed R-value, or bag count / coverage depth — only a vague lump sum.
- Skips air sealing and ventilation baffles; “we just blow it in” for a full attic job.
- Ignores vermiculite, wet insulation, or mold — or offers to cover hazardous material without testing.
- Spray foam over damp framing or no discussion of thermal/ignition barriers where codes apply.
- Large cash-only deposit before work, no written scope, no receipt.
- Pressure tied only to “rebate expires tomorrow” without leaving a detailed quote you can compare.
Next-step checklist
- Note climate zone goals, existing insulation type/depth, and any vermiculite or moisture history before quotes.
- Confirm licensing (if required) and get written proof of liability insurance (and workers’ comp if they have employees).
- Compare at least two written scopes with the same areas, products, R-values, air sealing, and cleanup line items.
- Ask about permits, electrical clearances, and vapor/ventilation details for your assemblies.
- If vermiculite or asbestos is possible, arrange testing before anyone disturbs the attic.
- Hold final payment until a walkthrough confirms coverage depth, clear vents/baffles, and agreed cleanup.