Procedure: Wall Top Plate and Plumbing/Electrical Penetrations
Expose the ceiling finish approximately 12" on both sides of the top plate. Clean area with brush or vacuum to ensure adequate sealant adhesion.Install flexible gasket or polyethylene sheet around larger penetrations such as plumbing stacks. Seal it with acoustical sealant, staple it to the ceiling, and clamp it to the vent stack with a pipe clamp. Alternatively, use high-performance flexible tape. This flexible air seal is to accommodate thermal movement of the plastic vent pipe.Install sealant around smaller penetrations such as electrical wires. Install spray foam over the top plate joints and other penetrations where needed to seal the ceiling to the top plate.Alternatively, cover the entire top plate with spray foam at the ceiling level to minimize air leaking at gaps, small penetrations and joints.
Replace existing insulation and install additional insulation.For homes with many interior walls and top plates at the ceiling, it may be prudent to completely remove the existing insulation in order to more easily view and access the top plates for repair.
