Wood-frame houses built before 1940, the kind you find in Jersey City Heights, Bayonne, Union City and West New York, usually have no insulation in the walls at all. Many are balloon-framed, which means each wall cavity runs unbroken from the basement to the roof, behind plaster and lath. Air moves up those cavities like a chimney, so the house loses heat in winter and picks it up in summer even when the attic has been done.
Dense-pack blown-in insulation fixes that without opening the walls. We drill small holes, either from outside with a course of siding lifted or from inside, and fill every cavity with cellulose packed tightly enough to stop air movement. The target for existing walls is R-13 to R-21. The same blown-in method also handles attics, where it is the standard way to reach R-49 to R-60.
What's included
- Wall check before drilling: framing type, cavity depth and any sign of moisture or old wiring.
- Dense-pack cellulose in every accessible wall cavity, installed with a hose through small holes in the siding or plaster.
- Attic blown-in insulation to R-49 to R-60 when it is part of the job, with baffles at the eaves.
- Closing and patching of every hole we drill.
- Careful handling around old wiring: knob-and-tube circuits can rule out filling a wall until an electrician has looked at it.
- Cleanup and a walkthrough with the finished areas shown to you.
What it costs in North Jersey
Typical range
$2.50 to $4.50 per sq ft of wall
Dense-pack wall insulation typically runs $2.50 to $4.50 per square foot of wall. For a two-story house that is typically $4,000 to $9,000, depending on how many walls can be filled and how the house is sided.
Blown-in attic insulation is priced the same way as on our attic page: typically $1.50 to $3.00 per square foot, or $2,200 to $4,800 for a 1,000 to 1,500 square foot attic with basic air sealing.
What moves the price
- Exterior: brick, stucco, vinyl and wood siding each need a different way in.
- Wall area: bay windows, dormers and additions add cavities.
- Obstructions: fire blocking and horizontal framing can mean extra holes per cavity.
- Wiring and moisture: problems found in the wall have to be dealt with before it is filled.
How the work goes
- 1
Assessment. We look at the framing, the siding and the attic, probe a few cavities and note anything that needs attention first. You get a written scope with ranges.
- 2
Protect. We cover floors and landscaping and mark every hole location with you.
- 3
Drill and fill. Holes go in, the hose goes in, and each cavity is packed to a firm density. Attics are blown to the target depth with depth rulers set.
- 4
Close up. We plug and patch every hole and remove all debris.
- 5
Walkthrough. Most houses take one to two days. We walk the work with you before we leave.
When to choose blown-in insulation vs spray foam
Choose blown-in for existing wall cavities and for open attic floors. It is the lower-cost option per square foot and it does not require the walls to come off.
Choose spray foam where there is nothing to blow into: a roof deck, a rim joist, or a cavity that is open to the framing. Foam also works where moisture is a concern and a closed-cell barrier is wanted.