Insulation Without Air Sealing Is Half a Job.
Insulation slows heat transfer. Air sealing stops air movement. In many existing homes, insulation and air sealing work together. Adding insulation without addressing significant accessible air-leakage pathways can leave important performance problems unresolved.
What Is Air Sealing?
Air sealing is the process of identifying and closing the gaps, cracks, and penetrations in your building envelope that allow conditioned air to escape and outside air to enter. These bypasses are often invisible — hidden in attic floors, wall top plates, around plumbing and electrical penetrations, and at the rim joist.
Where Air Leaks Hide
Attic floor
Top plates, partition walls, and framing gaps are major bypass routes — often hidden under existing insulation.
Rim joist
The band of framing at the foundation level is one of the leakiest areas in most homes.
Recessed lights
Old-style recessed cans are essentially holes in your ceiling — each one leaks significant air.
Plumbing & electrical
Every pipe, wire, and duct that passes through the building envelope is a potential air leak.
Attic hatch
Uninsulated, unsealed attic hatches are a direct connection between conditioned and unconditioned space.
Knee walls
In cape-style homes, knee walls and the floors behind them are common bypass routes.
Our Air Sealing Process
Assessment
We inspect accessible areas of your home to identify air-leakage pathways. When diagnostic testing is included in the project scope, blower-door testing and other building-science tools can help identify and evaluate significant air-leakage pathways.
Attic Bypass Sealing
We seal top plates, partition walls, penetrations, recessed lights, and other attic bypasses using caulk, foam, and rigid blocking as appropriate.
Rim Joist Sealing
Rim joists are sealed and insulated using spray foam or rigid foam board, addressing one of the most common leakage points.
Documentation
We document the work completed. Post-work diagnostic testing may be performed when included in the project scope.
Air Sealing + Insulation: The Complete Package
We air seal before adding insulation — not after. Sealing first means the insulation performs as intended. Adding insulation without addressing significant accessible air-leakage pathways can leave important performance problems unresolved. Attic insulation projects we do typically include air sealing as a standard part of the scope.
Stop Paying to Heat the Outdoors
For many existing homes, addressing significant air leakage can be an important and cost-effective part of improving building performance. We'll assess your home, identify the leaks, and give you a straight estimate.