Frequently Asked Questions

Published national ranges run $1.50 to $3.50 per square foot for open-cell and $3.00 to $5.00 for closed-cell (HomeGuide, 2026), and many installers have a job minimum of $1,000 to $2,000 or more. The total depends on how many square feet get sprayed and how thick. We measure and give you a written price.

It depends on the surface. Closed-cell suits rim joists, crawl space and basement walls and metal buildings because it is dense and resists moisture. Open-cell is a good value for walls and some rooflines. Many jobs use both.

The concern is usually about foam sprayed on a roof deck in a way that hides leaks or rot, or about poor installs that leave odors. Those are installation and moisture questions, not a reason to avoid foam everywhere. We check the roof and framing first and explain where foam belongs and where it does not.

Per inch, foam is higher: about R-3.5 to R-3.7 for open-cell and R-5 to R-7 for closed-cell, by HomeGuide's figures. Its bigger advantage is that it seals air at the same time. On an open attic floor, sealing plus blown fiberglass or cellulose can match it for less money.

The 2020 Indiana Residential Code lists R-38 for ceilings in Zone 5. For existing attics the Department of Energy suggests R-60 if there is nothing there now, or adding R-49 on top of 3 to 4 inches.

Plan on it. HomeGuide advises staying out for 24 hours or more after spraying. We ventilate the work area and tell you when it is safe to come back.

Yes. Closed-cell foam on steel or wood walls and the roof cuts condensation and makes the building usable in winter. We check the building first and schedule around the temperature.

Yes. We seal the vapor barrier, close the vents where it makes sense, and insulate the walls and rim joist. If there is a drainage problem we point it out before any work starts.

Foam that is installed correctly and kept dry does not sag or settle the way batts can. It should last as long as the framing it is sprayed on.

Standard spray foam needs open stud bays. For closed walls we usually recommend dense-pack blown insulation, or foam where walls are opened during a remodel.

Home centers sell canned foam and small two-part kits for sealing gaps and small areas. Whole rooms, rim joists around a full foundation and crawl space walls are normally done with professional equipment that mixes and heats the two parts at the gun.

There can be an odor while it cures, which is why the space is ventilated and occupants stay out for a day or more. A properly mixed and cured install should not keep smelling.

It can, which is why we check the roof deck and framing first and do not foam over active leaks or rot.

Usually yes, if the existing material is dry and clean. We seal the ceiling first and then add to the target depth. Wet, moldy or rodent-damaged insulation should come out first.

Most attic sealing and blown-in jobs in a typical Greenwood home take a day. Roof deck foam or removal adds time.

Not if the ceiling is sealed and the attic stays vented. Problems come from warm, moist house air leaking into a cold attic, which is what air sealing stops.

Yes. We weatherstrip the frame and add an insulated cover so the opening is not a hole in the ceiling.

Often, but only as part of sealing and insulating the space. Closing vents without a vapor barrier and a plan for moisture can make things worse.

In a damp climate, insulating the walls and closing the space usually works better than batts in the floor, which tend to get wet and fall.

HomeGuide lists spray foam on rim joists at $2,000 to $2,500. Length and access change the number, so we measure first.

Some homes do and some do not. We look at the space and moisture levels and tell you in the quote.

Yes. Dense-pack blown insulation goes in through small holes in each stud bay, which are then plugged and patched.

It costs more than batts but seals around wiring and framing and reaches higher R per inch. Many people use it on exterior walls and in rooms over garages.

The 2020 Indiana Residential Code lists R-20 or R-13 plus R-5 continuous for wood-frame walls in Climate Zone 5.

We drill carefully and pack at the right pressure. In older plaster homes we often drill from outside under the siding.

Closed-cell foam on the inside of the steel keeps the surface warmer and blocks moist air, which is what causes the dripping.

Yes, but surfaces need to be within the foam's temperature range. Unheated buildings may need to be warmed first or scheduled on milder days.

Thicker than in a cold storage barn. We base it on how warm you keep the shop and how much you want to spend on heat.

Yes. That ceiling is often the reason a room over the garage is cold, and foam seals and insulates it in one step.

In attics, usually yes. It fills around obstacles and leaves fewer gaps. Batts work in open walls when they are cut and fitted carefully.

Some, especially cellulose. We blow to a depth that still meets the target after settling.

Yes, if the old material is dry and clean. Wet or contaminated insulation should come out first.

Most take a few hours to a day, including air sealing.