Air Seal Attic Top Plate

Top plates are where a variety of building materials come together.

Air seal attic top plate. Air seal an attic series. Air sealing the wall plate around the perimeter of your attic blocks air from escaping around the outer edges of your home. 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.

Install spray foam insulation on the attic side over the entire ceiling deck. Conditioned air moving through light switches and other wall penetrations can find its way into the attic too. 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.

Figure 2 top plates may be missing where a lower ceiling meets the wall of a room with a higher ceiling. 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. Air seal the top plate to drywall seams to reduce air leakage in an existing home using one of the following or another method. The room most likely has drywall walls and ceiling that meet flush together.

Top plates are very leaky. Exterior top plates are inaccessible tyler tervooren posted in general questions on april 12 2019 07 40pm i am diligently spray foaming every top plate chase gap dropped soffit penetration etc. Think about the rooms right below the attic. Seal where the drywall meets the top plates to solve this problem.

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. 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.