Spray foam insulation is not a commodity. The difference between a properly installed job and a sloppy one can mean the difference between a home that’s significantly more comfortable and energy-efficient versus one with trapped moisture, voided warranties, or structural damage to the roof deck or floor joists. Choosing your contractor carefully is as important as choosing the right product.

In Michigan’s cold climate (Zone 5/6), spray foam thickness and vapor barrier placement are critical. Open-cell foam in the wrong location can allow condensation to accumulate inside the wall or roof assembly during Michigan winters. Getting the vapor profile right requires a contractor who understands cold-climate building science.

The 7 Questions to Ask Before Hiring

1. What specific spray foam system are you using, and why?

A contractor who can’t name the manufacturer and product line they’re installing, and can’t explain why it’s appropriate for your specific application, is a red flag. Open-cell and closed-cell foam have fundamentally different properties, and the right choice depends on where in your home it’s going, your climate zone, and your goals. If the contractor just says “we use spray foam,” dig deeper.

2. What thickness are you installing, and why?

Thickness determines R-value. In Michigan, typical applications range from 2 inches (R-12 closed-cell for rim joists) to 5–6 inches (R-30+ for roof decks). A contractor who gives you a square footage price without specifying installed thickness is quoting incomparable work. Get the thickness in writing.

3. Do you have manufacturer authorization for the product you’re installing?

Most major spray foam manufacturers (Demilec, Icynene/Huntsman, BASF, Lapolla/Covestro, Carlisle) offer contractor authorization or training programs. Authorized applicators have been trained on proper mixing ratios, temperature requirements, and application technique. This doesn’t guarantee quality, but unauthorized installers often produce off-ratio foam with dramatically reduced performance.

4. What are the temperature and humidity conditions required for installation?

Spray foam requires specific ambient and substrate temperature ranges to cure correctly — typically substrate temps above 50°F for most products. A contractor who doesn’t discuss installation conditions, or who dismisses the importance of substrate temperature, hasn’t been properly trained. Off-ratio or moisture-contaminated foam looks fine initially but fails to achieve rated R-values and can delaminate over time.

5. What does your warranty cover, and who backs it?

There are two separate warranties: the manufacturer’s product warranty (covering the foam itself) and the contractor’s workmanship warranty. Understand both. Manufacturer warranties on quality spray foam products typically run 10–25 years. Workmanship warranties vary by contractor — anything less than 2 years is short for this type of work.

6. How do you handle ventilation and occupant re-entry?

Spray foam off-gasses isocyanates during the cure process. The area must be vacated during installation and for a minimum period afterward — typically 24–48 hours depending on the product and ventilation conditions. OSHA and most manufacturers require proper respirator protection during application. A contractor who doesn’t address this is either skipping it or doesn’t know the protocol.

7. Can you provide local references from jobs completed in the past 12 months?

Recent local references are more valuable than portfolio photos. Ask to speak with 2–3 homeowners who had similar projects in Michigan in the past year. Ask those references: Did the crew show up on time? Did the finished product match the quote? Did you notice any performance difference, and were there any problems after installation?

Red Flags to Watch For

• No written quote with product specs, thickness, and R-value — walk away from verbal-only quotes
• Significantly lower price than other quotes — usually means thinner application, inferior product, or off-ratio foam
• Pressure to book same-day — legitimate contractors don’t disappear if you want a day to compare quotes
• No business address or verifiable online presence — spray foam work requires follow-up accountability; anonymous contractors don’t provide it
• Claims of R-values that exceed physics — closed-cell foam achieves about R-6.5 per inch; someone claiming R-10 per inch is misrepresenting the product
• Offering to skip permits — some jurisdictions require permits for spray foam work, particularly in attics. A contractor who routinely skips permits is signaling their relationship with code compliance generally

What a Proper Quote Should Include

Any legitimate spray foam quote should specify at minimum:

• Location in the home (attic, crawl space, rim joists, walls)
• Foam type (open-cell or closed-cell)
• Manufacturer and product name
• Installed thickness in inches
• Expected R-value
• Square footage being treated
• Any surface prep or removal of existing insulation included in the price
• Timeline and crew size
• Warranty terms

If any of these are missing, ask for them before signing.

What to Check After Installation

Once the work is complete and you’ve been cleared for re-entry:

• Verify the foam appearance — cured spray foam should be consistent in color and texture, with no voids, gaps at penetrations, or delaminated sections
• Check that penetrations (pipes, wires, HVAC lines) are properly filled and sealed, not just foamed around loosely
• Get the post-installation documentation — invoice with product specs, manufacturer data sheets, and the manufacturer’s certification statement (you’ll need this for the Section 25C tax credit)

Get Multiple Quotes from the Right Contractors

The right contractor for your project is one who answers all seven questions above confidently, provides a written quote with full specs, and has verifiable local references. Reach out for a no-obligation estimate — we work with crews in Michigan who meet this standard, and we’re happy to walk you through what to expect before you commit to anything.