Serving Nationwide, all 50 statesAttic Insulation Help connects you with licensed local companies. We are not a contractor and do not perform the work ourselves.
info@atticinsulationhelp.com
Attic Insulation Help
Email Us
United States

How much does spray foam attic insulation cost?

Spray foam attic insulation costs $2-$5 per square foot, the highest of common materials. See why it costs more than blown-in and where it earns the premium.

Request a Quote
How much does spray foam attic insulation cost?

How much does spray foam attic insulation cost?

Spray foam runs about $2 to $5 per square foot installed - the highest of the common attic insulation materials (HomeAdvisor, 2026), against $1 to $4 for blown-in and $2 to $4 for fiberglass batts. Closed-cell foam, which delivers the highest R-value per inch of any common option (roughly R-6 to R-7), sits at the top of that range.

How much does spray foam attic insulation cost?

Why does spray foam cost more than blown-in?

Spray foam does two jobs at once - it insulates and air-seals in a single application - while blown-in fiberglass or cellulose insulates only, at a lower R-value per inch. That dual function, plus the equipment and training spray application requires, is what drives the premium. Foam tends to earn that premium most at rooflines, rim joists, and tight spaces where blown-in cannot reach evenly. See the full [spray foam vs blown-in](/guides/spray-foam-vs-blown-in/) comparison.

Sources

2 cited
  1. Spray foam cost per square foot: HomeAdvisor, Attic Insulation Cost, 2026 (checked 2026-08-19).
  2. Closed-cell spray foam R-value per inch: LearnMetrics, Insulation R-Value Chart (checked 2026-08-19).
How it works

How blown-in insulation is actually installed

Four steps, done in order. The Department of Energy is explicit that skipping the air-sealing step is the most common way a new insulation job still leaves an attic underperforming.

Request a Quote
  1. 1

    Air seal first

    The EPA recommends sealing attic-floor penetrations before insulating, because loose-fill does not stop air moving through gaps around wiring, pipes and fixtures.

  2. 2

    Add baffles and depth markers

    Rafter baffles keep blown material off the eaves where it could get wet, and depth rulers mark the target R-value before the blower starts.

  3. 3

    Blow to depth

    A pneumatic machine feeds loose fiberglass or cellulose over the attic floor, covering the tops of the joists so heat cannot bypass the insulation.

  4. 4

    Verify and clean up

    The settled depth gets checked against the target R-value for your climate zone, then tools and debris are cleared.

How we work

What this site will and will not do

We explain the R-value target and the real cost drivers first, and we do not sell you the installation - which is why we can say plainly when topping up beats a full replacement.

01

R-value before a quote

ENERGY STAR recommends R-30 to R-60 depending on your climate zone. Knowing your target before you call means you can hold every bid to the same number.

02

Air sealing first, always

The Department of Energy is explicit that insulation slows heat flow but does not stop air leaks - sealing gaps first is what makes the insulation you pay for actually perform.

03

We are not the installer

We do not install anything ourselves, so we have nothing to gain from steering you toward the bigger job. Licensed local companies do the work and quote it themselves.

04

Nothing we cannot source

Every figure on this site traces to a named, dated source - HomeAdvisor, the DOE, ENERGY STAR, the EPA or the FTC. Where we have not sourced a number, we say so instead of guessing.

Questions

Frequently asked

The questions people actually type before calling a company.

Request a Quote
Is spray foam more expensive than blown-in insulation for an attic?

Yes. Spray foam runs $2 to $5 per square foot installed, versus $1 to $4 for blown-in (HomeAdvisor, 2026). Foam air-seals as it cures, which is part of why it costs more.

Is spray foam worth the extra cost in an attic?

Often only in specific spots - rooflines, rim joists, and tight spaces where air-sealing and insulating in one step pays off. For a standard attic-floor top-up, blown-in usually reaches the target R-value for less money.

Get matched with a licensed local insulation company

Request a QuoteEmail Us
Request a QuoteEmail Us