You seem to doing the interior and exterior walls. It is a little
unclear from what you wrote.
No vapor barrier and insulation is needed for interior walls. If you
want improved sound reduction, use heavier or even better two thinner
No vapor barrier is needed if the insulation has Kraft paper, but
personally I would add it. I would also not bother with the Kraft paper
House wrap on the outside is a good idea. It does two things. First it
blocks air flow and it adds one additional water (not vapor) barrier under
your siding. Both are good things. Do use housewrap however NOT plastic.
Note: if you are in a part of the word where it is very warm most of the
year and you have air conditioning on most of the year, you need to make
some adjustments to the usual arrangement.
Joseph E. Meehan
26 + 6 = 1 It's Irish Math
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