PoleBarnGuru
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Glad to be able to contribute.POLEBARNGURU : Welcome!
Some good ideas in that post. I was already prepared to block between girts. Wiring, no problem, everything will be on the surface in conduit as I always do.
Count me as one of those people unwilling to double the girts too. My main reason for using the bookshelf system is ease of finish. And economy of materials of course. If I was willing to use double girts, I'd let the builder build using standard external girts, then I'd put a whole second set between like bookshelves, insulate between, and finally sheet internally. All the girts would be 2x4, and the builder's bill would be lower. But to my thinking, if using 2x6 laminated columns and 2x6 bookshelf girts (fully blocked), I am building with about as little amount of wood as possible (for a completly insulated and internally sheeted).
What is BIBS ? Sounds like maybe "blown in something something".
You did not mention Tyvek or similar -- assuming you would want to use this on the outside, and a vapor barrier on the inside just under the sheeting.
(quote) Most people are not willing to go through the effort of the double layer of girts, in which case, use a girt one size larger than the columns (2x8 on 6x6, etc.), setting the girt so 1-1/2" hangs past the exterior face of the column. You will find this installation method allows to compensate for any irregularities in the column dimensions and creates a deeper insulation cavity. Side benefits - electrical can be run around the outside of the columns, without the need to drill through them to run wires. On walls which are a multiple of 3' in length, it also saves having to rip the edge of a panel off either the first or last sheet of steel on the wall. (end quote)
This is interesting and I will think about it. At least you reminded me to add 2 inches to my plan in each direction, as I forgot about that last sheet covering 2 extra inches.
I would not recommend the use of 2x6 "laminated" columns, unless they are truly glu-lams. Nailing up three 2x6s together and calling it a "column" is not without some issues. Having tested them to failure at the University of Oregon Forest Products laboratory, we found the middle ply of 3 ply 2x6 columns fails far below the expected point. Why? Because the middle ply has twice as many nails into it.
We also found them to be very flexible in the "weak" direction (the 4-1/2" direction), so much so that it was nigh on impossible to hold the building still long enough to be able to square the building up, with the problems becoming progressively worse as the building eave height increases.
For information on BIBS insulation: Blow-In-Blanket Insulation System: Home Page This is not a product the company I work for has any financial connection to, or sells. It is just a great product.
Keep in mind house wraps have no R value, they create no thermal break. For about the same price, you can use reflective insulation. You get an R value, plus the product is great for helping to prevent heat gain. See Buy Reflective Insulation | Foil Insulation | Radiant Barrier | Vapor Barrier for lots of information and great prices.
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