Frequently Asked Questions
Spray Foam Insulation Questions
How much should I expect to pay for spray foam insulation?
HomeGuide's 2026 figures put installed spray foam at $1.50 to $5.00 per square foot, rim joists at about $2,000 to $2,500 and a whole house at $8,000 to $20,000. Your written estimate after the visit is the price.
What is the downside of spray foam insulation?
It costs more per square foot than cellulose or fiberglass, is hard to remove once cured, and the house needs to be empty for about a day while it cures. It also seals so well that moisture and ventilation need planning. Where those trade-offs do not pay, we recommend something else.
Why are people removing spray foam insulation?
Usually because it went in wrong: too thick, over a leak, mixed badly, or hiding damage an inspector wanted to see. HomeGuide puts removal at $1.00 to $2.50 per square foot.
Why is spray foam insulation now a red flag for some buyers?
Mostly because of poor installs and foam that covers the roof deck so inspectors cannot see it. A careful plan, the right thickness and paperwork showing what was installed answer most concerns.
What R-value should a York attic have?
Pennsylvania's code lists R-49 for ceilings in Zone 4. ENERGY STAR recommends R-60 for an existing Zone 4A attic with no insulation, or adding R-49 over 3 to 4 inches.
Can you insulate a rowhome roof with no attic?
Usually, by filling the shallow roof cavity with closed-cell foam or blown insulation through small openings, after checking the roof for leaks.
Spray Foam Insulation Questions
Is spray foam good for a York rowhome?
In the right spots: the rim joist, the shallow roof cavity when it is opened, and back additions. Party walls are usually shared masonry and are left alone.
Which foam has the highest R-value?
Closed-cell, at about R-5 to R-7 per inch.
How long should we stay out?
HomeGuide recommends at least 24 hours.
Does exposed foam need covering?
Usually a thermal or ignition barrier, which we plan in the quote.
Attic & Knee Wall Insulation Questions
What R-value should my York attic have?
Code lists R-49 for Zone 4 ceilings; ENERGY STAR suggests R-60 for an uninsulated Zone 4A attic.
Why is my third floor so hot?
Usually thin knee walls and sloped ceilings plus air leaks. Sealing and foam there fix most of it.
Will this stop ice dams?
Air sealing, insulation and clear eave vents are the main fixes.
Can new insulation go over old?
Usually, if the old is dry and clean.
Basement & Rim Joist Insulation Questions
Is rim joist foam worth it in a rowhome?
Usually yes; the front and back rims leak a lot of air and there is little rim to cover.
Can you foam a damp stone basement?
Only after the water source is handled.
What R-value do basement walls need?
Pennsylvania's Zone 4 summary lists R-13 cavity or R-10 continuous.
Does foam need covering in a basement?
Usually a thermal or ignition barrier.
Wall Insulation for Rowhomes & Older Homes Questions
Can you insulate brick rowhome walls?
Solid brick cannot be filled; insulating from inside during a remodel is the main option.
Will dense-pack settle?
Not when installed at proper density.
What about knob-and-tube?
It must be checked or replaced before walls are filled.
Is the party wall insulated?
Usually not needed; it is shared with a heated home next door.
Garage, Shop & Pole Barn Insulation Questions
Will foam stop my shop from sweating?
Yes, closed-cell keeps moist air off the steel.
Can you work in winter?
Yes, with the space warmed.
How thick should foam be?
It depends on how warm you keep it; we quote it in writing.
Do I need a permit?
Check with your township; rules vary.
Insulation Removal & Replacement Questions
How do I know it should come out?
If it is wet, moldy, smells or shows droppings.
Can you remove vermiculite?
Only after testing; positive material needs a licensed abatement contractor.
How long does it take?
Most attics take a day.
Do you reinsulate after?
Yes, after sealing the attic floor.