Thoughts on Larsen Truss wall idea
After watching the video(s) regarding interior poly as an air barrier (http://www.greenbuildingadvisor.com/blogs/dept/musings/using-interior-po...) I started to think about using Tyvek (or similar) for an exterior sheathing (in a non-structural role) to hold in dense pack insulation. A similar technique was used to insulate the cathedral ceiling in a demonstration home built in the videos in the previously mentioned blog link.
Attached is a graphic of my idea.
There have quite a few many homes built with a a similar wall system, but the key difference is that the exterior sheathing (non-structural) layer is just Tyvek stapled on instead of fiberboard, Agepan or plywood. The primary advantages that I see is that there is reduced material cost and the Tyvek is high perm. The primary disadvantages that I see are that the labor increases some and the only lateral loading support on the I-joists is the 1x3 furring strips (horizontal). Moreover, there could be some bulging of the Tyvek, but this should be mitigated by the horizontal furring strips and the gap should be large enough that is won't affect the siding (1.5").
I wanted to see if there were any other thoughts on this idea?
Other discussions on similar wall systems can be found here: http://www.greenbuildingadvisor.com/blogs/dept/musings/klingenberg-wall
(Note, the double top plate is due to the discomfort of the local framers with using a single top plate for whatever reason.)
Posted Sat, 02/08/2014 - 15:37
Edited Sun, 02/09/2014 - 07:19
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