Attic Insulation Cost 2026: $1,800–$4,000 Typical US

Blowing cellulose or fiberglass into a common unfinished attic — about 1,000 to 1,500 square feet of attic floor, brought to a target around R-38 to R-49, over insulation that is dry enough to stay — often clusters around $1,800–$4,000. The wider national spread, about $1,000–$9,000, covers a small top-off at the low end and a larger attic, haul-away of the old fill, a real air-sealing package, or dense-pack of slopes and kneewalls at the high end. Spray foam on a roof deck is the spray foam insulation guide, typically $3,000–$5,000 for about 1,000 square feet of open-cell, and a large closed-cell deck can clear that spread. Vermiculite abatement and dense-pack of the whole house’s walls can clear it too. This is a planning range, not a quote.

This page is a vented, unfinished attic on a single-family house. A finished room in the attic, a cathedral ceiling opened from below, and a wall dense-packed from the outside are different projects.

Attic floor area is not living area. A compact two-story can have half the attic of a ranch with the same bedrooms. Square-foot rates are easy to misuse. Twelve hundred square feet is not twice the price of six hundred, because the trip, the blower, the baffles, and the hatch do not shrink in half. Price the attic you can see, not a rate you saw on a forum.

A common attic inside the typical band usually lands around $1.50–$3.50 a square foot of attic floor. That rate is a cross-check, not a bid. Two hatches and a kneewall do not get cheaper because the attic is small.

The rows below are ways to read one attic. They are not added together. The per-square-foot rate is the cross-check for a floor already inside the typical band. Spray foam on the roof deck is a different product, priced on the spray foam guide, and it replaces a blown-in top-off.

Scope	Typical cost
Blown cellulose or fiberglass, about 1,000 to 1,500 sq ft, toward R-38 to R-49	$1,800–$4,000
Per square foot of attic floor, inside that band	$1.50–$3.50
Open-cell spray foam, about 1,000 sq ft, on the spray foam guide	$3,000–$5,000
Wider national spread	$1,000–$9,000

What the range includes

The typical band assumes an existing single-family house, an unfinished vented attic a person can get into through a hatch, blown cellulose or blown fiberglass brought to a common target around R-38 to R-49, and existing insulation that is dry, even, and left in place. It includes eave baffles so the soffit vents stay open, dams so fill does not fall down the hatch or onto a flue, and ordinary cleanup. Where a rebate program or the city wants an inspection, ask who handles it. A full haul-away of the old insulation is not included.

Colder climates often aim higher, around R-49 to R-60. A mild climate may stop lower. Local code and the climate-zone recommendation are the target, not a single national inch count. The bag label is what that R-value means for that product. Cellulose at R-49 often settles around 14 inches. Blown fiberglass usually needs more depth for the same R. A bid that quotes inches and will not name the product and the settled R is not ready to compare.

A small attic, or a few inches added over a decent layer, with a hatch the crew can use and a truck that can park, sits toward the floor of the wider spread. A bare attic going all the way to R-49, or one with several baffles and a kneewall, sits at the top of the typical band and leaves it when the old fill has to come out.

The floor of the national spread, near $1,000, is a small top-off on easy access. It is not a dense-pack job that someone discounted. The top, toward $9,000, is where a larger attic, removal of the old insulation, a listed air-sealing package, and dense-pack of sloped ceilings and kneewalls usually land. Closed-cell spray foam on a large roof deck, mold remediation, or vermiculite abatement can clear that top. Treat a number above it as a different scope and ask which driver caused it.

None of the bands include a new roof, new windows, a furnace or an air conditioner, a bath fan ducted to the outside, or a rewire. If the attic is wet because the roof leaks, price an asphalt roof on the roof replacement guide, or a metal roof on the metal roof guide, before anyone blows insulation over the stain. New windows are a separate envelope bid. A furnace or a condenser sized to make up for a bare attic is the furnace guide or the central air guide, and it is the wrong first purchase. A one-time ant or spider treatment is the pest control guide, often $100–$500. Eighteen hundred, this typical floor, is $1,300 past that pest top. One thousand, this wider floor, is $500 past that pest top. Do not fold those into the insulation bid, and do not fold the treatment into the blanket.

As a cross-check, not a bid: a top-off on a small, open attic is often discussed toward the floor of the national spread, and a full air-sealing package plus dense-pack of the slopes is often discussed from the top of the typical band into the wider spread. Ask for blow-in only, and blow-in plus air sealing, as two proposals if you are deciding how far to go.

What moves the price

Driver	How it changes the bid
Area	More attic floor is more material. The setup charge does not shrink just because the hatch is over a small closet.
Starting depth	Adding a few inches over a dry layer is less cellulose than a nearly bare attic brought to R-49.
Material	Blown fiberglass and cellulose are the typical band. Cellulose often costs a little more and reaches the same R in less depth. Spray foam is a different assembly.
Target R	R-38 is less depth than R-49 or R-60. The settled R on the product chart is the number that matters, not the depth on the day of the blow.
Air sealing	Sealing top plates, wire and pipe holes, chases, and the hatch is labor before the blower starts. A package that includes it sits above a blow-only bid.
Dense-pack	Loose-fill is the open attic floor. Dense-pack is for closed cavities: kneewalls, sloped ceilings, sometimes walls. It is slower and it belongs in the wider spread.
Removal	Dry, even fill can stay. Wet, moldy, pest-soiled, or vermiculite fill has to be handled first, and that haul-away is often a four-figure line.
Access	A walk-in attic is easier than a scuttle with no decking. Low pitch and tight trusses slow the crew.

Air sealing is the part people skip because it does not show up as a thicker blanket. The hatch, the top plates of the walls below, plumbing stacks, and an open chase can move more comfort than another inch of cellulose. A bid that says “air seal” and lists nothing is a blow-in with a better adjective. Baffles at the eaves keep the new fill off the soffit vents. Insulation that plugs those vents turns a hotter attic into the next problem. Intake and exhaust are the roof guide, not a thicker layer on the ceiling.

Do not bury a recessed light that is not rated for insulation contact, and do not cover a bath fan. A fan that dumps into the attic is moisture you are about to hide. Vent it outside before you add fill. That duct is closer to the bathroom remodel guide than to a bag of cellulose. Live knob-and-tube in the attic is an electrical job before it is an insulation job. Do not cover it. A service upgrade, if you need one, is the electrical panel guide. Abandoning old wiring is not that bid, and it is not an insulation add-on.

A cold house is not automatically a small furnace. Price a thin attic here before you price a larger unit on the furnace guide or the central air guide. New windows on the same comfort complaint are the window guide. A cold floor over a damp crawl is the crawl space encapsulation guide, not another inch of cellulose.

DIY or hire

An open, unfinished attic is a realistic project for someone who can stay on the joists, set baffles so the soffits stay clear, seal the large holes, and blow cellulose or fiberglass to a settled depth the bag chart calls the target R. Many retailers include a blower rental with a minimum purchase of bags. The savings is the labor. The risks are a foot through the ceiling, soffit vents buried under fill, and insulation over a problem that should have stopped the job.

Hire dense-pack. It is blown into closed cavities under pressure, and a bad job can blow drywall off or leave a slope empty. Hire spray foam, especially foam on the roof deck, which turns a vented attic into an unvented one. That is a different assembly, not a thicker blanket, and it belongs with a contractor who will say what happens to the ridge vent. Price that foam on the spray foam insulation guide. Hire any attic you cannot move through without stepping on the ceiling, and any attic with a roof leak, mold, or animals.

If the fill looks like small pebbles, treat it as vermiculite until someone qualified says otherwise. It can contain asbestos. Do not vacuum it, bag it, or blow new insulation over it. Testing and any abatement are a different scope and can clear the spread on this page.

Repair or replace

Top off when the insulation that is already there is dry, not matted, and simply short of the target. Even, clean cellulose or fiberglass can stay. Rake it level only if you can do that without spreading dust through the house and without disturbing vermiculite. Then add enough to reach the settled R you actually want.

Remove and replace when the fill is wet, moldy, packed with nesting material, or compressed to a crust. New cellulose on a soaked attic holds the water against the ceiling. If the sheathing above it is stained or soft, the roof is the project. Price an asphalt roof on the roof replacement guide, or a metal roof on the metal roof guide, and let the attic dry before anyone insulates. A stain on a bedroom ceiling is not automatically thin insulation. Water can travel along a rafter and show up far from the hole.

Vermiculite stays put until it is tested. Do not add a layer over it. If the fill mats into clumps or darkens the ceiling under it, it is wet, and the inch count does not matter until the attic is dry. If the depth is already at the target and the house is still uncomfortable, look at the hatch, the can lights, the ducts, and the windows before you buy more bags.

How to use this number

Ask for bids that state the square feet of attic floor, the material, the target R and the settled depth, whether the existing insulation stays, whether baffles and a hatch cover are included, which holes get sealed, and whether removal is included. Compare a blow-in of cellulose or fiberglass on a dry open attic with the typical band. Compare a small top-off with the floor of the wider spread. Compare removal, a listed air-sealing package, and dense-pack with the wider spread, and make air sealing a line you can see so you know the bags versus the caulk.

A very low bid on a bare attic going to R-49 is a reason to ask whether baffles, dams, and air sealing were left out, not a reason to celebrate. A high bid should point at removal, dense-pack, spray foam, or contamination. Two or three local bids on the same attic and the same target R are the number that matters. How this site sets the band is explained on the methodology page.