Frequently Asked Questions

National guides put installed foam at $1.50 to $5.00 per square foot (HomeGuide), with closed-cell at the top of that range. A whole house runs $8,000 to $20,000 by HomeGuide's figures, while a single addition or attic is far less. We measure and send a written price.

It depends on the spot. Closed-cell gives R-5 to R-7 per inch and slows moisture, so it suits tight roof lines, rims and floors over garages. Open-cell costs less per square foot and fills irregular cavities well. Many houses get both.

Mostly in the attic and walls. The slab carries the radiant heat, so the work is usually sealing and insulating the attic floor or roof line, filling empty exterior walls where they are open or can be drilled, and dealing with additions built over porches or garages.

Foam does not feed mold and closed-cell resists water, but no insulation stops mold if a leak or damp air keeps surfaces wet. We find and fix moisture sources first, then insulate.

Closed-cell foam, at R-5 to R-7 per inch by HomeGuide's figures, about twice open-cell's R-3.5 to R-3.7. That makes it the choice where depth is limited, like a cathedral ceiling or low-slope addition roof.

HomeGuide advises allowing at least 24 hours before re-entering. We confirm the time for the product we use when we schedule, and we close off the work area while we spray.

Yes. On a wide attic floor, blown cellulose or fiberglass over sealed leaks is often the better value. We quote foam and blown-in side by side when both would work.

ENERGY STAR recommends R-60 in zone 4A for an attic with no insulation, or adding R-49 when three to four inches are already there. We measure what you have and quote the depth to get there.

Open-cell is soft, R-3.5 to R-3.7 per inch, and lets some vapor through. Closed-cell is rigid, R-5 to R-7 per inch, and slows vapor. Open-cell costs less per inch; closed-cell does more in tight spaces and damp spots.

Not with standard spray foam, which needs open framing. For closed walls we use injection or dense-pack methods instead. See our wall insulation page.

On the original attic floor, sealing plus blown-in is usually the better value. Foam pays off on additions, cathedral ceilings, floors over garages and anywhere space is tight.

There can be an odor during and shortly after spraying while it cures. That is why we ventilate the space and you stay out for the re-entry period.

Several national chemical companies make the two-part systems installers use. We tell you the product planned for your job on the quote, along with its R-value per inch.

If you can see the tops of the ceiling joists, there is almost certainly less than R-30. Hot upstairs rooms in summer and high cooling bills are other signs. We measure and tell you.

Only if it is wet, moldy, contaminated by rodents, or in the way of sealing. Clean, dry insulation can usually stay, with new material added on top.

Yes. We seal the duct runs we can reach, or recommend foam on the roof deck so the ducts end up inside the insulated space.

On an open attic floor, sealing plus blown-in usually gives the most R-value for the money. Foam makes more sense on the roof deck or in tight sections.

Yes. Dense-pack cellulose or injection foam goes in through small holes drilled in each stud bay, from inside or outside, and the holes are patched.

Pull an outlet cover on an exterior wall with the power off and look beside the box, or we can check with a small test hole. We do this on the visit.

For closed walls, dense-pack is usually the practical choice. Spray foam needs open framing; when walls are open, closed-cell gives the most R-value in a shallow wall.

Wall insulation alone rarely makes a house too tight. If we do extensive air sealing as well, we talk about bath and kitchen ventilation.

If the crawl space holds ductwork or plumbing, sealing it and insulating the walls usually works better. If it is a simple, dry vented crawl, insulating the floor above can be enough. We explain the choice for your house.

Batts do not stop air, and air is the main problem at the rim. Closed-cell foam seals and insulates in one layer and slows moisture.

It cuts the moisture that feeds mold by keeping humid air and ground moisture out. Existing mold or wet wood should be dealt with first.

Maybe not for the original house, but often for an addition built over a crawl space, or a porch enclosed into living space. We check those on the visit.

Per square foot, yes, usually by a wide margin. HomeGuide lists blown-in at $1.00 to $2.80 per square foot versus $1.50 to $5.00 for foam. On an open attic floor, sealing plus blown-in is often the better value.

Cellulose settles a little after install, which is accounted for in the installed depth. Fiberglass settles less. We blow to the depth needed after settling.

Yes, if the existing insulation is dry and clean. Wet, moldy or rodent-damaged material should come out first.

Most single-family attics take a day or less, including the air sealing. Dense-pack walls take longer because of drilling and patching.

Not always. If it is dry and clean, we can add to it. If it is wet, moldy, rodent-soiled or blocking air sealing, it should come out.

The vacuum runs to bags or a container outside, so material does not pass through the living space. We cover the access area and clean up.

We do not touch it. We recommend testing, and if it contains asbestos, a licensed abatement contractor handles removal.

Usually because it was installed over a leak, applied badly, or needs to come off for roof work. Correctly installed foam rarely needs removal.