When a North Jersey house is cold in winter and hot in summer, the attic is the first place we look. An inch of old rock wool is about R-3. Most pre-1980 attics we open in Bergen County are at R-11 to R-19, and the target for our climate is R-49 to R-60. That gap is why the upstairs rooms never feel right, no matter how the thermostat is set.
We start with the air, not the insulation. We seal the gaps around chimneys, plumbing stacks, wiring holes and recessed lights, then blow in cellulose or fiberglass to R-49 to R-60 (about 14 to 18 inches) with baffles holding the vents clear. In two-family houses in Hudson and Essex, where one heating system serves everyone and the top floor complains first, we treat the whole building at once so the tenants are not fighting over the same problem.
What's included
- Attic inspection: depth and type of the existing insulation, ventilation, moisture stains and any sign of roof leaks.
- Basic air sealing of the attic floor: top plates, chimney and flue chases, plumbing and wire penetrations, recessed light housings.
- Baffles at every eave vent, so insulation never blocks the airflow that keeps the roof deck dry.
- Blown-in cellulose or fiberglass installed to R-49 to R-60.
- Insulated and weatherstripped attic hatch or pull-down stair, which is the leak most people forget.
- Depth rulers set in the attic, so you can check the coverage yourself.
- Removal and disposal of old or damaged insulation when it is needed, listed as its own line in the estimate.
What it costs in North Jersey
Typical range
$1.50 to $3.00 per sq ft
Blown-in attic insulation, whether you are topping up what is there or starting over, typically runs $1.50 to $3.00 per square foot. For a 1,000 to 1,500 square foot attic that is typically $2,200 to $4,800, including basic air sealing.
A full attic job, with air sealing, baffles and new insulation to R-60, typically runs $4,500 to $9,000 per attic. Removing old material is priced as its own line at $1 to $2 per square foot, so you can see exactly what it adds.
What moves the price
- Access: a tight hatch, knee walls or low rafters slow the work.
- Removal: matted, wet or contaminated insulation has to come out before new material goes in.
- Target depth: R-49 and R-60 use different amounts of material.
- Air sealing: more penetrations and more recessed lights mean more sealing work.
How the work goes
- 1
Assessment. We measure the existing depth, check ventilation and look for moisture or roof leaks. It is free, and you get a written scope with ranges.
- 2
Prep. We protect the path to the attic, then set baffles and dams around flues and recessed lights.
- 3
Air sealing. Gaps and penetrations are sealed with foam and sealant before any insulation goes down.
- 4
Insulating. Insulation is blown to the target depth, with rulers placed so you can verify it.
- 5
Walkthrough. Most attics take one day, a few take two. We walk the finished attic with you and clean up.
When to choose attic insulation vs spray foam
Blown-in insulation on the attic floor is the right answer for most unfinished attics with a standard vented roof. It costs less per square foot and reaches R-49 to R-60 without trouble.
Spray foam on the roof deck makes sense when the attic is finished or converted, when ductwork or a furnace lives up there, or when the rafters are too shallow for the depth you need.