Frequently Asked Questions
Spray Foam Insulation Questions
How much does it cost to spray foam?
HomeGuide lists installed spray foam at $1.50 to $5.00 per square foot, with closed-cell at $3.00 to $5.00. Thickness and access drive the final number; we measure and quote in writing.
Why is spray foam insulation now a red flag?
Some buyers and inspectors worry about poor installs: foam over wet or rotten wood, wrong mix ratios or foam hiding roof leaks. Careful prep, the right foam for each surface and a written record of what was installed address those concerns.
Does Lawrence, Kansas get snow?
Yes, though not a lot by northern standards. Wikipedia's 1991-2020 table lists about 10 inches a year, with a record low of -25F. Cold snaps still drive heating bills, which is why air sealing pays.
Can you insulate an old house without removing plaster?
Yes. Dense-pack cellulose goes in through small holes, from inside or outside, and the holes are patched. Balloon-frame cavities are blocked first.
What R-value does Lawrence require in attics?
The city's 2018 IECC table lists R-49 for ceilings in zone 4 for new work. ENERGY STAR recommends R-49 added over 3 to 4 inches for existing homes.
How long do I stay out after spray foam?
HomeGuide advises at least 24 hours. We give you the time for the product used.
Spray Foam Insulation Questions
Is spray foam safe for old houses?
Yes, on the right surfaces. Closed-cell on rims and foundation walls works well; in walls, we make sure the exterior sheds water and there is no active moisture first.
Can spray foam go into closed plaster walls?
Standard spray foam needs open cavities. For closed walls we dense-pack cellulose.
Will foam hide knob-and-tube wiring?
We do not cover active knob-and-tube; have it evaluated by an electrician first.
How long does it take?
Rims take a few hours; a remodel's open walls usually a day.
Attic Insulation & Air Sealing Questions
Why seal before insulating?
Insulation slows heat but not air. Sealing stops the air that carries most of the heat.
What is balloon framing?
Older framing where wall studs run from the foundation to the roof, leaving cavities open between floors.
Can you blow over vermiculite?
No. Vermiculite should be tested first and removed by an abatement contractor if it contains asbestos.
How long does an attic take?
Most take a day.
Dense-Pack Wall Insulation Questions
Will dense-pack damage my plaster?
The holes are small and patched. Some touch-up paint may be needed.
Can you insulate from outside?
Yes, depending on your siding.
Does cellulose settle in walls?
Dense-packed walls are filled tight to limit settling.
Is this OK for historic districts?
Inside access leaves the exterior untouched.
Crawl Space & Rim Joist Insulation Questions
Should I close my crawl space vents?
If the crawl is sealed and insulated with a vapor barrier, yes. We explain the full approach.
Does foam stick to stone?
Yes, on clean, dry surfaces. Damp stone needs moisture handled first.
Is a rim joist rebate available?
Evergy's Kansas chart lists $50 for at least 50 linear feet. Check eligibility.
How long does a rim job take?
A few hours for most houses.
Pole Barn & Metal Building Insulation Questions
Will foam stop my pole barn from dripping?
Yes. It keeps warm, moist air off the cold steel.
Can you spray over old fiberglass blanket?
Only if it is dry and well attached. Wet blanket comes out first.
Do I need to empty the barn?
Move items away from the walls and cover them.
Can you do just the roof?
Yes, it is a common first step.
Insulation Removal Questions
Do I have to remove old insulation?
Only if it is wet, moldy or soiled. Clean, dry insulation can stay.
What about vermiculite?
Leave it alone and have it tested.
Can you clean out a crawl space?
Yes, including fallen batts and old vapor barrier.
How long does removal take?
Usually a day.