Green Building Q&A: What are the negative aspects of using Tyvek on a double wall system instead of plywood sheathing?
I am detailing the exterior walls to be a double wall, its sequence as follows from interior to exterior: gypsum board on structural 2x6 with rockwool insulation, 1/2" plywood sheathing, continuous 10 mil vapor/air barrier, 11 7/8" TJI joist with dese packed cellulose insulation, 1/2" plywood sheathing, WRB membrane, 1x3 rainscreen furring strip and hardi-plank siding. I have read Thorsten Chlupp's wall detail that uses Tyvek thus eliminating the use of the 1/2" plywood and WRB membrane. I would like to go down this path because of the economy of materials but am not sure about using only Tyvek at that location. Any guidance would help.