One of the things I have learned through my “net zero” education is the importance of sealing up the shell of the buildings. I witnessed the haphazard performance of the advanced weather barrier wraps over the years, and it seemed like it was time for an advance in science and methodology of these wraps. And technology has come through. Drain plane wraps are a step in the right direction.
The one that caught my attention because of the scientific information, couple with the basic toughness of the product, was Tremco, made by the same people that make foundation sealants. It is water permeable, while performing at a high level for air tightness. This tightness, modified my original intention to build super thick walls, and instead enhance air barrier system. Admittedly. this is a test for me in my own lab, to try my personal selection of materials.
An additional feature of this flexible sealant, is its ability to seal around the staple/nail hole of the siding fastenings.
It feels like I’m coating my home in black, but I know that it will keep me in the black, and in the warm pink, for a years to come.
An aspect that needs to be discussed with this air tightness coupled with a well insulated structure, is the over all-efficiencies that we actually achieve. We should down-size our heating/cooling systems. With the structure performance plus the Milgard Monticeto windows this is a high performance package. We are using Jacobs Heating & Air Conditioning to engineer out equipment. We are using a Panasonic ductless heat pump with actual ducts inside the conditioned envelope. (sounds like jumbo shrimp) The equipment does not have backup heat available, because it does not need it, it operates down to 0 degrees. We tested the duct system, using Better Air NW, at 50 pascals of pressure we had 50 cubic feet of leakage. . . less then 3% leakage, pretty good, plus it is leaking into the interior of the building!