The basement walls are insulated, but your ankles still know it's January. Before the ceiling closes, look at the awkward strip where the floor framing meets the outside wall. It's easy to miss from the middle of a freshly finished room.
Find the overlooked edge of the room
NRCan's basement guide identifies the joist-header area as an important air-leakage location. Its treatment varies with construction. Inspect for dampness and deterioration before choosing the assembly; the hidden edge is not a suitable place to bury an unresolved problem.
Resolve the detail before the finish sequence
Ask the contractor to show where the air barrier continues around the perimeter and how pipes, cables, and obstructions are handled. Confirm material compatibility and any required protection for exposed insulation. Photograph completed work before ceiling framing makes it inaccessible. Keep necessary service clearances and access intact.
Before the next step
- Inspect the perimeter before installing soffits.
- Ask how the air barrier connects to adjacent assemblies.
- Record the completed details before concealment.
Before the drywall date, ask to see that perimeter strip and the completed air-barrier connections. Take the photographs while there's room to get your phone in, not after the soffit is in the way.