Frequently Asked Questions

Per inch, closed-cell foam is near the top: HomeGuide lists R-5 to R-7 per inch, against R-3.5 to R-3.7 for open-cell. That matters in tight spaces like rafters, rim joists and three-decker walls where there is no room for thick batts. In an open attic, depth is cheap, so loose fill can reach R-60 for less.

Foam does not kill mold, but it can stop the warm, damp indoor air that condenses on cold surfaces and feeds it. Closed-cell foam on a rim joist or basement wall keeps that air off cold wood and concrete. If there is an active leak or wet framing, that has to be fixed first, and we point it out before quoting.

HomeGuide's 2026 range is $1.50 to $5.00 per square foot installed: $1.50 to $3.50 for open-cell and $3.00 to $5.00 for closed-cell. Fixr lists $3.15 to $7.50 for existing walls. Your written estimate after a visit is the actual price.

The stretch code summary from the Insulation Institute lists R-60 for ceilings in Climate Zone 5, which covers all of Massachusetts. That applies to new work. For an existing home it is a good target, and many older Worcester attics are well below it.

Mass Save lists 75 to 100 percent off approved insulation improvements after its no-cost Home Energy Assessment. The incentive applies to work approved through that program, so book the assessment first if you want it. For work outside the program, such as a garage ceiling or a shop, we price it directly.

Knob-and-tube wiring was common until the 1940s, and city guidance from Boston says an inactive system does not stop insulation. A live system is different and needs an electrician before anything covers it. We check during the visit and tell you what we find.

Closed-cell, in most cases. It slows vapor and does not absorb water, so it keeps damp indoor air off cold concrete and the rim joist. Open-cell can trap moisture against cold surfaces in our climate.

Foam that stays dry and protected does not settle or sag the way loose fill can. It is usually expected to last the life of the building. Damage comes from leaks, pests or later remodeling.

In living spaces and many basements, foam must be covered by a thermal barrier such as drywall, or use a product rated for exposure. We explain what your space needs before you sign.

Yes, in heated spaces. Unheated attics and garages are harder in deep cold because the surface and the material need to be within a working temperature range. We plan the date around that.

Sealing and insulating the attic floor cuts the heat that melts roof snow, which is the main cause of ice dams. Ventilation and roof shape also matter, so we look at the eaves and soffits too.

Only if it is wet, moldy, full of rodent waste or blocking the air sealing. Dry, clean insulation can stay, and new material goes on top. Vermiculite should be tested before it is disturbed.

Many single-family attics are done in a day. Capes with kneewall attics or homes that need removal can take longer. The quote gives you a time estimate.

Often yes, but many have a shallow space under a low-slope roof. Sometimes we can blow loose fill in from a small opening; other times foam at the top-floor ceiling or roof deck works better. We look before recommending one.

Yes. Dense-pack cellulose goes in through small holes, from outside under the siding or from inside through the plaster. The wall stays in place.

Loosely blown material can settle. Dense-pack is blown at a high density specifically so it does not, and it also slows air moving through the bay.

Dense-pack cellulose is the usual choice for closed walls in older homes because it fills around obstructions and costs less. Foam is best when the wall is open.

No. We can work from inside, or lift and replace sections of siding. If you are re-siding anyway, that is a good time to fill the walls.

It is one of the best values in insulation because the rim leaks air around the whole house and the job is small. Most homeowners notice warmer first-floor rooms.

We usually remove it. Foam needs to bond to the wood to seal, and old batts often hide moisture or mouse damage.

It depends on the town and the scope, especially if you are finishing the space. Check with your local building department; we can describe the work for your application.

No. Foam is not waterproofing. Leaks have to be fixed with grading, gutters or drainage first.

It has cold air below and often an unsealed kneewall attic beside it. Air moves through the floor framing and around the batts. Sealing the floor and kneewalls usually makes the biggest difference.

Not always. Sometimes we can fill the floor bays from the side attic or through small openings. In other cases removing the drywall gives the best result. We explain the options.

Sealing the floor framing closes most of the air paths between the garage and the room. We also check the door between the garage and the house.

Not usually. Dry, clean insulation can stay. Removal makes sense when it is wet, moldy, contaminated by rodents, or in the way of air sealing.

It looks like small gray-brown or gold pebbles, lightweight and loose. If you see it, do not disturb it and get it tested. We point it out during the visit.

Many attics are cleared in a day. Large attics, heavy contamination or tight access can take longer. The quote includes a time estimate.