Thanks to Huber's ZIP System, these walls will be insulated by a three-in-one sheathing
The original 1970s home was built with 2x4s, and so that was matched for new wall framing, with one noticeable upgrade: Wall sheathing would be not just OSB, but Huber Engineered Wood’s ZIP System Insulated R -Sheathing. The product comes with the notable advantage of being a moisture, air, and thermal barrier all in one.
In this case, the finished product is 1½” thick, thanks to Owens Construction's use of 1” of polyisocyanurate foam bonded to a ½” ZIP panel (the sheathing and exterior insulation so preferred by the IECC codes). The 2015 IECC specifies for Climate Zone 5 a wall R-value of 20, or R-18 if you use at least R-5 exterior insulation. The 1½” insulated sheathing here is rated at R-6.6, and the cavity fiberglass will be R-13, for a total wall R-value of at least R-19.6.
To stabilize the frame, Bill Owens’ crew started at the corners and worked down the wall. “I’ve worked with ZIP a lot, but this was my first time using the insulated panel,” says Owens. “The only change I had to make was to buy a larger coil nailer that could handle the 3-inch nails it takes to get 1½” penetration into the studs.”
Owens added that the inspector allowed them to tape the seams on the roof to get it watertight, but still wanted to see the nailing on the wall sheathing. “So, we’re holding off on taping the wall seams for about a week until the next inspection,” he says.