Air-sealing at Every Stage
Solid blocking at the ceiling line of the rake walls is integral to air-sealing the house.
Huber Zip System wall sheathing is our primary air-control layer, and we sealed it to the top plate of the second-story walls — where there was a top plate. Because we framed the rake walls with continuous studs from the second-floor deck to the roof sheathing line, we needed to install a row of blocking at the ceiling line. These blocks serve several functions: The building code requires solid blocking on tall walls at prescribed elevations, the blocking will provide a nailing base for the drywall, and the blocking transfers the air seal from the Zip sheathing to the primary ceiling air-control layer: CertainTeed MemBrain.
Bruce cut the blocks to fit tight between studs. To ensure a good seal, he ran a generous bead of TiteBond acoustical sealant along the inside of the Zip sheathing and the sides of the studs. When we install the MemBrain, we’ll bed the sheet in a bead of sealant applied to the face of the blocking.
