Frequently Asked Questions

HomeGuide's 2026 guide lists $1.50 to $5.00 per square foot installed, with rim joists at $2,000 to $2,500 and an attic at $3,000 to $8,000. Size, access, foam type and removal change the total. The written estimate after our visit is the price.

Most concerns trace back to bad installs: foam sprayed too thick at once, foam over a leak, or a sealed attic or crawl space planned without thinking about moisture and the HVAC system. Lenders and inspectors also ask about foam that hides roof sheathing. A clear plan, the right thickness and paperwork showing what was installed answer most of those questions.

Mold needs moisture and food. Cured foam is not a good food source, but mold can grow on dust or on wood next to foam if water gets in. Closed-cell foam resists water; open-cell can hold some. The real protection is keeping water out: fix leaks and drainage before insulating.

Per square foot, blown-in fiberglass or cellulose is cheaper: HomeGuide lists $1.00 to $2.80 per square foot versus $1.50 to $5.00 for foam. Foam costs more but seals air in the same step, which matters on rim joists, basement walls and steel. We recommend each where it pays.

Indiana's code summary lists R-38 for ceilings in Climate Zone 4. ENERGY STAR recommends R-60 for an uninsulated Zone 4A attic, or adding R-49 to one with 3 to 4 inches.

In most Evansville houses with a basement or crawl space, yes. The rim joist is often bare or stuffed with loose fiberglass and leaks cold air all winter. Closed-cell foam seals and insulates it in one step; HomeGuide lists the job at $2,000 to $2,500.

On rim joists, foundation walls, crawl space walls and steel buildings, usually yes. In interior walls or above-grade cavities, open-cell often does the job for less.

In heated basements, yes. Cold attics and unheated buildings may need temporary heat or a milder day.

HomeGuide advises at least 24 hours.

Closed-cell slows vapor and keeps warm, moist air off cold surfaces. It does not fix leaks and is not waterproofing.

The Insulation Institute's summary of the 2020 Indiana Residential Code lists R-38 for ceilings in Climate Zone 4. ENERGY STAR suggests R-60 for an uninsulated Zone 4A attic.

It cuts the heat that melts roof snow, which is the main cause. Good ventilation helps too.

If what is there is dry and clean, add on top after sealing. If it is wet, soiled or blocks sealing work, remove it first.

Most sealing and blown-in jobs take a day.

In most older houses, yes. It stops perimeter drafts and warms floors. HomeGuide lists it at $2,000 to $2,500.

Yes, foam needs to bond directly to the wood.

Not until the water problem is solved.

In finished or occupied spaces it generally needs a thermal barrier unless the product is approved for exposure.

In a damp crawl space, usually. It cuts musty air and condensation and warms floors. It depends on how wet the space is now.

A sealed crawl space needs a way to stay dry: a dehumidifier or conditioned air.

Sealing vents and insulating the walls keeps the crawl space warmer in winter, which helps protect pipes.

Ask your pest company what they need. Some want an inspection gap at the top of wall insulation.

To stop condensation, a modest layer of closed-cell on the roof steel is often enough. A heated shop needs more. Thickness and R-value are on the quote.

Yes, if the building and steel can be brought into the working temperature range, often with temporary heat.

Closed-cell bonded to the steel keeps warm, moist air off the cold metal, which is what causes the drip.

It depends on the building and use. Check with your county building office.

In attics, usually, because it fills around joists and wiring without gaps.

Often, with dense-pack through small holes, after checking wiring.

Some, which is accounted for in the installed depth.

HomeGuide lists blown-in attics at $900 to $3,600 nationally. Your written estimate is the price.