Replies

1. 
   Nick_Pitz | Jan 24, 2000 06:33pm | #1

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   Boone -

   I'm assuming you mean some kind of 1/2" foam insulation, and not "blueboard" as in plaster board for skimcoat. If you do mean foam insulation, then I have done this quite a few times. We use 1/2" R-max (foil faced polyiso), nail it up with as few roofers as possible, and tape the joints with Tyvek tape. There are a few things to look out for. Obviously, you have to set all electrical boxes farther out to make them come flush with the drywall. Also, make sure you mark all your nailers and studs carefully before you put the R-max up. It's tough to find them again later. Make sure you set the roofers deep in the R-max so they don't mess up the drywall later. When you put up the drywall, use a tight screw pattern, and double screw 1-2" inches apart, like they used to recommend for ceilings. The problem is that the drywall doesn't always get pulled tight to the insulation, and the later, especially when you nail on baseboards or casings, you get screw pops from the drywall moving. No matter how careful you are, you will get a few screw pops anyway, but just figure on going back and checking after the drywall finisher is done. Obviously you will also have to make extension jambs for your doors and windows. This is all a lot of work, but it works very well to form a good vapor barrier and stop conduction through the studs. I wouldn't necessarily want to use plastic over the insulation.

   P.S. - if you use a foil-faced insulation, forget about using a stud finder after the drywall is up. The foil prevents the stud finder from reading the studs.

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   Laura_Stanley | Feb 10, 2000 05:09pm | #2

   *Nick, I found your comment that you would not necessarily use a plastic vapor barrier over foam insulation intriguing. My husband and I purchased a 1965 circa redwood 'kit' house a year ago. It was originally a summer weekend home. The interior walls were redwood, no insulation, no drywall...very dark and not at all energy efficient..we're located in Leesburg, VA. Our renovation has included replacing all the old single pane windows with Andersons and putting up 2 inch foam insulation, vapor barrier, and then drywall. A friend in the 'interior climate' business said that we didn't really need the vapor barrier. Well, we have one more room to do and I'm interested to know if, with the type of exterior walls (redwood) and insulation I've described, if we need to put up the plastic vapor barrier. I'd appreciate your insights.Laura Stanley

2. 
   Boone_Guyton | Feb 10, 2000 11:19pm | #3

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   are there any draw backs to adding 1/2 inch blueboard to the inside wall framing for extra insulation and then the poly over that as far as moisture problems?? I know about the trim problems. It will have 1/2 inch sheetrock as wall cover