New loose fill can hide penetrations and make later sealing harder. The right sealant and detail depend on the gap and assembly, so this guide inventories openings without assigning unsupported generic material rates.
- Do not block intentional ventilation.
- Use approved details around heat-producing fixtures and flues.
- Document work before it is covered.
Formula or decision boundary
air-sealing inventory = count and dimensions of accessible leakage paths by approved detail typeProject order
| Order | Task | Exit condition |
|---|---|---|
| 1 | Inspect | hazards and moisture identified |
| 2 | Repair | water/unsafe conditions addressed |
| 3 | Air-seal | accessible boundary documented |
| 4 | Insulate | label coverage and clearances maintained |
Use the answer
Map the boundary
Trace the ceiling plane and mark penetrations, chases, top plates, and access.
Resolve exceptions
Get qualified input for combustion, electrical, fire-protection, and suspect-material conditions.
Photograph then cover
Keep an accessible record of completed details and product labels.
Safety and scope
- Do not seal combustion-air openings or cover unapproved fixtures.
- Active moisture and unsafe wiring require correction before insulation.
Sources and scope
Source links reviewed July 16, 2026. A review date is not the document's publication date.
- ENERGY STAR: Attic InsulationUnited States · government guide
Air leaks and moisture conditions should be addressed before insulation is added.
- Natural Resources Canada: Keeping the Heat In — Roofs and atticsCanada · government guide
Follow product labels for bag count and settled depth; do not disturb suspected vermiculite.