Replies

1. 
   Michael Chandler | Sep 13, 2009 11:19am | #1

   Stanley

   I looked into this in some depth about a year ago for a prospective client. The system has been around for over 20 years but has failed to get much of a market share. The issue seems to be that the final product sets up rigid and brittle and wood frame buildings settle and move with the seasons which leads to gaps at the intersections of the wood and the aircrete. In the end we chose to change from open cell spray foam in our 2x6 walls to the new JM Spider micro-filament blown-in fiberglass and the prospective client chose to work with another builder.

   My favorite wall system at this point is a double 2x4 wall with a 2 1/2" gap between (2x10 upper top plate) netted and stuffed full of the Spider with 1/2" OSB exterior sheathing. If I didn't live in a hurricane area I'd be looking at a foam board exterior sheathing system such as is featured in most of the CAD details on this site.

2. 
   homedesign | Sep 13, 2009 11:31am | #2

   Michael,
   I am not in hurricane country......we do get tornadoes
   I like full structural sheathing too...
   9-1/4" - 3-1/2" - 3-1/2" = 2-1/4" ;-)

3. 
   Michael Chandler | Sep 14, 2009 12:44am | #3

   John,

   You're always there with a calculator when it's needed, and you're right of course but...

   The way that really happens in the field is that they snap out the lines on the floor to 9 1/2, split 2x6s into two 2 5/8" purlins in the middle and then sort of torture it all back towards 9 1/2 at the top with the 2x10 kinda fittin' okay (at least compared to grandpa's house).

   There is some old carpenters saying about "cut once, beat to fit" that works here.