Frequently Asked Questions

National guides put installed spray foam at about $1.50 to $5.00 per square foot (HomeGuide), with closed cell at the high end, and many jobs carry a $1,000 to $2,000 minimum. A rim joist job and a whole-house job are very different numbers, so we measure and give you a written price.

Mostly because of poor installs and roof decks. Foam that was mixed or sprayed badly can smell and fail to cure, and foam sprayed under a roof deck hides the wood, so a slow leak can go unnoticed. That is why some inspectors and buyers ask questions. We check the roof first, spray to written thickness and tell you when blown-in is the better choice.

It usually is not, but some inspectors and lenders want to know who installed it, what product was used and whether the roof deck can still be checked. Keep your estimate, product name and invoice with the house records so you can answer those questions.

Spray foam insulates and air seals in one step because it sticks to the surface and fills gaps. Fiberglass and cellulose slow heat flow but do not stop air on their own, so the leaks need sealing first. Foam costs more per R-value, so we use it where sealing matters most.

Closed cell, in most cases. It goes on the rim joist and concrete walls without soaking up moisture and slows vapor at normal thickness. Open cell is better suited to attic rooflines and interior sound control.

Utility rebates pay by area insulated, not by material. DTE lists $600 for 500 square feet of attic insulation and $50 for rim joists for homes it heats, and Consumers Energy lists attic rebates of $125 to $200 for its gas and combination customers. Check each program's rules before you start.

Several chemical companies make two-part spray polyurethane foam, in both open-cell and closed-cell formulas. What matters for your house is the product type, the thickness and how it is installed, so we name the product on your estimate and can share its data sheet.

Two to three inches is common, which gives roughly R-10 to R-20 at HomeGuide's R-5 to R-7 per inch. We write the thickness on the estimate.

Not well. Foam needs to stick to clean framing or sheathing to seal, so old batts in the way are pulled first.

Once it has fully cured and the space has aired out, it is inert. The risk is during spraying and curing, which is why the house should be empty for at least a day (HomeGuide).

For new homes, Michigan's energy code sets ceiling insulation by climate zone, and the 2021 IECC the state has been adopting calls for R-60 in Zone 5. Existing homes do not have to be upgraded, but the Department of Energy recommends R-60 for an empty Zone 5 attic.

Sealing and insulating the attic floor removes most of the warm air that melts roof snow, which is the main cause. Roof shape and ventilation matter too, so we check both.

Both work over a sealed floor. Cellulose is denser and resists air movement a little better; fiberglass is lighter. We tell you which we plan to use and why.

Most attic sealing and blow-in jobs take about a day. Removal of old insulation can add time.

Yes, if you heat the basement or want warmer floors upstairs. The rim joist leaks air whether or not the basement is finished.

Foam can cover the sill and seal around wires and pipes. We keep it off things that should stay accessible, like electrical boxes.

Building codes generally require foam in living spaces to be covered by a thermal barrier such as drywall. Your building department sets the specifics.

It stops damp outside air coming in at the rim, which helps. A musty smell from water or mold needs the source fixed first.

Not with standard spray foam, which needs open framing. Closed walls are filled with injection foam or dense-pack cellulose through small holes.

In a sound wall, a properly filled cavity is fine. Walls with leaks or no siding protection need repair first, which we check.

Often a strip is lifted and replaced. Working from inside through plaster avoids the siding entirely.

A typical older house takes one to three days, depending on the number of walls and access.

Usually because the floor batts have gaps and the joist cavities open to the attic, so cold air flows under the room. Sealing and insulating the floor fixes it.

Not always. Foam needs open framing, but dense-pack can go in through small holes if the drywall stays.

If the garage is heated, an insulated door helps. We insulate walls and ceilings; doors are a separate trade.

Yes. Ceilings under living space need the right drywall, and foam needs proper covering. We keep that intact.

Closed-cell foam on the steel keeps warm, moist air from reaching it, which stops most condensation.

For condensation control on an unheated building, about an inch is common; heated shops need more. We size it to your use.

Foam should go on clean steel or framing. Loose wraps are usually removed first.

Foam in occupied buildings usually needs an ignition or thermal barrier. Requirements depend on use; we tell you what applies.