Now on to the part everyone loves… Framing. Although our site supervisor wasn’t overly excited about this house. Our walls are 10-1/2″ thick (including exterior foam) and take a little bit of planning to account for things like installing windows, doors, and siding! Our primary load bearing exterior walls are 2×6 and we offset the walls inward to account for the 4″ of exterior foam. The plan is for the exterior foam to match up with the outside of the foundation wall, so obviously we offset the wall 4″ to account for this.
In an effort to manage water if it were to collect in the layers of foam sheathing, we installed Dow Weathermate butyl flashing on the face of the OSB sheathing and out on to the top of the foundation to direct water out and away from the bottom plate of the wall assembly. The door and window buck extensiosn serve multiple purposes; 1. It is difficult, and expensive, to have exterior door jambs made in a 10-3/4″ depth, so the offset buck allows us to use a smaller jamb (inset) into the wall opening, 2. It allows us to have a nailing surface on the windows by only having to penetrate 2″ of foam rather than all 4″, 3. By overlapping the second layer of 2″ foam over the buck, we create a thermal break in the rough frame.
This is also the first home I’ve used an 18″ Energy Heal truss on…. And believe it or not, there was little to no difference in cost from a 12″. My local truss supplier built the added height truss for no extra cost, but the benefit is monumental. The extra 6″ really helped us in the living room/ kitchen area where we are using scissor trusses. I use cellulose in the attic, and to achieve the R-65 value, we need approximately 19″ of cellulose. That being said, our insulation depth will be uniform from heal to heal.