The walls and ceiling between the garage and the interior of the home must be sealed properly, otherwise there is a risk of car exhaust entering the home. Particular attention must be given to any penetrations from the garage to the interior made by pipes or wires. These will usually come through the shared header area between the garage and interior.

When using the polyethylene as your barrier between the house and the garage, all joints, junctions, seams, and penetrations must be sealed.