Insulating scissors trusses — best practice or economics?
I'm going to build a one story house with walk out basement in northern Idaho, east of Coeur d'Alene. The main roof will be scissor trusses with a 16" heel. With an 8/12 pitch roof and 4/12 pitch ceiling. Due to the spans, there will probably be a 7' to 8' space at the peak between the roof and ceiling. The roof will be standing seam metal and the finish ceiling will first get a taped drywall ceiling and thane 1x T&G boards over that.
I am considering CC spray foam under the roof deck and an unvented ceiling. Another option mentioned to me was to forgo the high cost of the foam and use batts with blown in on top of that with a vented roof assembly.
For the latter, would I need a vapor barrier somewhere in the assembly and or would I need rigid insulation between the roof sheathing and the finish metal roof?
I've been in construction over 35 years and lately the more I read up on newer thoughts and ideas, the more I find out what I don't know.
My last name is not Rockefeller so I am torn between what may be the best practice for the situation and economics. Any advice would be appreciated.
Posted Fri, 02/28/2014 - 11:58
Edited Fri, 02/28/2014 - 13:24
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