Most homeowners think about adding insulation when they want to improve energy efficiency. But without air sealing, new insulation can't perform at its full potential. Air leaks allow conditioned air to escape and unconditioned air to enter — regardless of how much insulation you have.
The Scale of the Problem
The average home has enough air leaks to equal a 2-square-foot hole in the wall. That's like leaving a window wide open, year-round. These leaks are spread across dozens of small gaps, cracks, and penetrations — individually small, collectively enormous.
Top Air Leak Locations
- Attic penetrations (30-40% of total leakage): Wiring, plumbing, HVAC chases, recessed lights, attic hatches
- Rim joists (10-15%): The joint between your foundation and first floor framing
- Windows and doors (10-15%): Gaps in weatherstripping, caulking, and framing
- Ductwork (15-20%): Leaky ducts in unconditioned spaces
- Electrical and plumbing (5-10%): Outlets, switches, and pipe penetrations on exterior walls
- Foundation/basement (5-10%): Cracks, gaps at sill plate, and utility entries
How Air Sealing Works
Different materials seal different types of leaks:
- Caulk: Small gaps (less than 1/4 inch) around windows, trim, and fixed joints
- Expanding foam: Medium gaps (1/4 to 3 inches) around pipes, wires, and irregular openings
- Weatherstripping: Moving joints — doors, operable windows, attic hatches
- Rigid materials: Large openings — framing chases, duct boots, dropped soffits
- Spray foam insulation: Provides insulation and air sealing simultaneously for crawl spaces and rim joists
Why It Matters
Air sealing alone can reduce energy costs by 10-20% with an investment of $500-$1,500 — often the fastest payback of any home improvement. Combined with insulation upgrades, the impact multiplies.
Contact us for a professional air sealing assessment.