<!-- Place this tag where you want the widget to render. --> http://yellowpages.superpages.com/reviews/userreviews.jsp?&LID=5YysEMCl/sDpCPT7k4xZww== A Practical Air-Sealing Sequence by Andrew Webster If you aim to build a super-insulated airtight home and want to keep it affordable, your best bet is to use common materials and methods that don’t disrupt traditional work sequences very much. Last year, my architecture firm’s founding partner, Bruce Coldham, developed a set of details to create an affordable, durable, and continuous air barrier for a house with a conventionally framed 2x6 wall and a truss roof. Airtight wall sheathing We opt to use the exterior face of the wall sheathing as the air barrier, using either Huber Zip sheathing and Zip tape or a handmade version: OSB with Grace’s WB Primer and Vycor tape at all joints, burnished or rolled to get the best adhesion. This strategy keeps the air barrier out of the way of the electricians and plumbers who are called on to punch many holes in our walls. It also provides a durable, inspectable, and affordable solution to reducing air leaks. With a continuous layer (or two) of rigid polyiso over the OSB, we get warm sheathing and good overall wall R-values as well. The wall-roof intersection For reasons of construction economy, many clients want trussed roofs with traditional eaves and a ventilation channel. The immediate challenge in this design is figuring out how to connect the exterior sheathing air barrier on the walls to the interior drywall air barrier at the ceiling. The solution is found in a simple plywood cap plate (3/4 in. by 8 in.) that is attatched to the exterior walls. To achieve airtightness at this transition requires the use of construction adhesive in two locations: The wall sheathing has to be sealed with adhesive along the 2x6 top plate, and the plywood cap plate has to be sealed to the 2x6 top plate that it’s nailed to. Doing it this way doesn’t interrupt the construction sequencing, and the materials needed to accomplish it are typically on site already.