Most R-value per dollar
Blown-In Insulation in Oshkosh, WI
Loose fill over a sealed attic floor, or dense-packed into older walls.
- Free on-site estimates
- Written quote by area with R-values
- Damp basements and roof leaks flagged before work
Loose Fill Done Right
Blown-in insulation is loose cellulose or fiberglass delivered through a hose. On an open attic floor it is usually the least expensive way to reach a high R-value, since it fills around joists, wires and pipes without cutting. In older Oshkosh homes it is also how we fill walls that were built empty, without removing plaster or siding.
Cellulose or fiberglass
HomeGuide rates cellulose at R-3.1 to R-3.8 per inch and blown fiberglass at R-2.2 to R-2.9. Cellulose is denser and slows air a little better; fiberglass is lighter and does not absorb water. Either works at the right depth over a sealed ceiling.
Dense-pack walls
For closed walls, we drill one hole per stud bay, usually from outside behind a course of siding, and blow cellulose in at high density so it fills the whole cavity and resists settling. The holes are plugged and patched. We look for knob-and-tube wiring before filling any wall.
Sealing comes first
Loose fill does not stop air. In attics we seal the bypasses, insulate the hatch and set baffles at the eaves before we blow. That work is its own line on the quote.
Blown-In Work
Attics, walls and the sealing that goes with them.
Attic top-ups
Fill added over existing insulation to reach target depth.
Dense-pack walls
Cellulose blown into closed walls and patched.
Air sealing
Bypasses sealed before the fill goes in.
Baffles
Soffit vents protected.
Published Blown-In Insulation Costs
| Job | Range and source |
|---|---|
| Blown-in, per sq ft | $1.00 to $2.80 (HomeGuide); $1.65 to $3.80 (Fixr) |
| Attic | $900 to $3,600 (HomeGuide); $1,750 to $5,500 for about 1,500 sq ft (Fixr) |
| Exterior walls | $1,900 to $7,800, $1.10 to $3.70 per sq ft (HomeGuide); $2,000 to $4,000 (Fixr) |
| Dense-pack cellulose | $1.60 to $4.20 per sq ft (HomeGuide) |
| Fiberglass / cellulose | $1.65 to $2.60 / $1.75 to $3.80 per sq ft (Fixr) |
| Typical job | $800 to $3,000 (HomeGuide); $3,000 to $7,000 (Fixr) |
HomeGuide (November 2025) and Fixr (August 2025) provide these national figures. Depth, access, sealing and any removal change the cost. The written estimate we give you after the visit is the price.
How Blown-In Work Goes
1. Inspect
Existing depth, wiring and leaks checked.
2. Quote
Depth, R-value and sealing itemized.
3. Seal
Bypasses sealed and baffles set.
4. Blow and verify
Fill to depth; walls checked bay by bay.
Why Choose Us for Blown-In Insulation
Sealed first
No loose fill over open bypasses.
Wiring checked
Old wiring found before walls are filled.
Every bay filled
We probe for blocking in walls.
Blown-In Insulation Questions
What is cheaper, spray foam or blown-in insulation?
Blown-in is cheaper per square foot. HomeGuide lists it at $1.00 to $2.80 per square foot versus $1.50 to $5.00 for foam. Foam earns its cost where air sealing and moisture matter most.
Will dense-pack settle in my walls?
Installed at proper density, cellulose resists settling.
How deep should blown-in be in my attic?
Enough to reach R-49, the ceiling value in Wisconsin's Zone 6 code summary. For cellulose that is roughly 13 to 16 inches.
Can you blow insulation over old batts?
Yes, if they are dry and clean, after sealing.
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Get a Blown-In Insulation Estimate
Ask us how much depth your attic is missing.