Where heat usually escapes
- Attics and the top-floor ceiling.
- Rim joists and basement walls.
- Gaps around pipes, wires and recessed lights.
- Ductwork running through unconditioned spaces.
Common insulation types
| Type | Often used in | Note |
|---|---|---|
| Fiberglass batts | Open walls and floors | Needs a snug fit without gaps or compression. |
| Blown-in cellulose or fiberglass | Attics and wall cavities | Fills irregular spaces. |
| Spray foam | Rim joists, rooflines | Also seals air. Professional installation is common. |
| Rigid foam board | Foundation and exterior walls | Good moisture resistance. |
Air sealing in plain words
Caulk, spray foam and weatherstripping close gaps where air moves. Many utilities and local programs describe how to find leaks, sometimes with a blower-door test. Check what is offered where you live.
Moisture and ventilation
Tighter homes can trap moisture. Bath fans, kitchen hoods and attic ventilation should keep working properly. Ask any installer how they plan for moisture.
Questions worth asking
- Will air sealing be done before insulation?
- What R-value will be installed, and where?
- How will recessed lights, vents and chimneys be handled safely?
General information only. Gablevo is not a contractor, remodeler, lender, insurer, or licensed professional, and this is not professional, legal, or financial advice. Codes, prices, and practices vary by location and change; check with a licensed professional and your local building department. Updated October 30, 2026.