Spray Foam Questions, Answered Straight

Closed-cell foam runs about $1.50 per board foot - a board foot being one foot by one foot, one inch thick. So three inches in a wall works out to $4.50 per square foot of wall. Full breakdown of how that works here.

That is our rate, though, not your total. What we cannot do is price your job over the phone, because the total depends on how thick the assembly needs to be and how hard the space is to get into - a crawl space you belly-crawl through costs more per foot than an open new-construction wall. The rate is public; the total needs somebody to look at the building. The walk-through is free.

Sometimes not, and we will tell you when. If your walls are already open and you are heating with oil, closed-cell in the right places usually pays for itself in a few winters. If you have a finished house with decent existing insulation and no draft problem, we might point you at injection foam instead, or tell you to leave it alone.

What we will not do is quote the whole house when the attic is the problem.

Closed-cell where moisture and strength matter, open-cell where you need to fill an awkward space and want to spend less. Most jobs use both, in different places. Full comparison here.

Yes, but not with spray foam. Spray foam has to go into an open cavity - it expands hard enough that filling a closed wall can bow your drywall. For finished walls we use injection foam or dense pack, which go in through small holes we patch afterwards.

Plan on more than a day. The spray itself is often a single day, but a complete insulation job also means air sealing every penetration and crack in the exterior wall, and blowing the attic where that is the right answer. Together that regularly runs several days, and on a full house it can take the better part of a week.

The foam goes in after the plumber and electrician have finished their rough-in and before the drywall goes up. If we are doing your drywall too, that is one schedule instead of two. More on how the job runs.

Maine is climate zone 6. Current guidance for a new build is R-60 in the roof and attic and R-30 in the walls. You can also get there by REScheck, or by a blower door test under three air changes per hour - worth settling with your code official early, because it changes what you have to buy.

R-value on its own is only half the story - a wall stuffed with R-21 fiberglass that leaks air at every seam performs worse in February than a properly sealed wall with less nominal R-value. More on that here.

No. Venting exists to carry moisture out of fibrous insulation so it can keep working. Foam is a solid cell structure - air and moisture do not move through it, so there is nothing to vent off. Closed-cell cathedral ceilings and roof decks do not need a vent channel.

No. It is adhered to the framing rather than stuffed between it, so there is nothing to fall down. As an inert plastic in a wall cavity it lasts as long as the building.

That is the main practical difference from the fiberglass we pull out of forty-year-old Maine attics, which has usually compressed to half its thickness and slid down the rafter bays.

No formaldehyde resins. Once cured it is inert - the resins are similar to the polyurethane varnish on a wood floor. During the spray itself the house needs to be clear and our crew is in respirators, which is why we schedule it as its own day.

Usually, because ice dams are a heat problem rather than a gutter problem. Warm air escaping into the attic melts the snow on the roof, the water runs to the cold eave and refreezes. Seal the ceiling and the roof stays cold. More on ice dams.

Yes. Denmark is about ten minutes from the line and we work both sides of it regularly - the Conway area, Ossipee, Wolfeboro, Bartlett, Jackson and the towns around them.

Yes. Hanging, taping and skim coat plastering, same crew. Most insulation contractors stop at the foam. More on the finish work.