Green Building Library
Advanced Air Sealing:
Connections Between Floor and Exterior Wall
Some builders use caulks or gaskets under the bottom plate of an exterior wall. To expand and contract, caulk requires a joint that’s at least 1/8 in. x 1/8 in. Setting a wall on top of a bead of caulk simply mashes the caulk, leaving nothing to fill a gap that may open in the future. Another gasket is needed between the bottom plate and the drywall. Here’s a simpler way:
Seal the joint between the subfloor and the drywall or other interior wall covering.
Sealing this leakage site after the drywall saves the framing crew an extra step while they’re trying to put up the walls. It also makes it possible to do the sealing work when the home is weather-tight. This step can be postponed until just before the finish floors go down.
This method requires some surface preparation. Brush away dust and loose debris before caulking.
