Air Seal Attic Top Plate

Figure 2 top plates may be missing where a lower ceiling meets the wall of a room with a higher ceiling.

Air seal attic top plate.

It s usually the hardest place to air seal because the cramped space underneath the eaves where the roof rafters rest on the outer wall makes it hard to move your hands and head. Conditioned air moving through light switches and other wall penetrations can find its way into the attic too. Install spray foam insulation on the attic side over the entire ceiling deck. Seal where the drywall meets the top plates to solve this problem.

When they push the drywall toward the plates they leave a gap to prevent damage from thermal expansion and contraction. Install spray foam insulation on the attic side of the ceiling at the eaves. Sealing wall intersections get your finger ready and some caulk spray foam or acoustical sealant. The open wall cavities should be closed off with an air blocking material like rigid foam plywood or dimensional lumber that is cut to fit the stud cavity and sealed in place with caulk or spray foam or fiberglass batt insulation that is rolled and friction fit into place and air sealed.

Throughout the attic of our 1960s ranch before adding add l insulation. Think about the rooms right below the attic. These are often found in the top plate drop soffits and chases and the volume of conditioned air that escapes through them is equivalent to leaving a window wide open the year round. Top plates are a focal point in almost every energy audit and air sealing job we perform.

Top plates are where a variety of building materials come together. A big culprit for air leakage in a home is through holes in the floor of the attic. The room most likely has drywall walls and ceiling that meet flush together. Air seal the top plate to drywall seams to reduce air leakage in an existing home using one of the following or another method.

In most houses that gap doesn t get any kind of air sealing so attic air can leak into the house or conditioned air can be pulled into the attic depending on the pressure differences. Air seal an attic series.