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Community and Q&A

Vapor barrier or not?

martyrg | Posted in Green Building Techniques on

I’m building a heated workshop in SE Michigan – Climate zone 5.  Insulated slab with 6 mil vapor barrier.  I’ll be using a Reznor sealed combustion unit heater- 83% efficent.  This is my wall assembly: 5/8″ T1-11 plywood siding, 3 coats of acrylic paint, Tyvek, 2×6 studs and rockwool insulation.  I plan on using the Air Tight drywall method.  Do I need a vapor retarder?  If so would vapor barrier paint do the trick?

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  1. Jon_R | | #1

    Make sure that the wall complies with the recommendations in Table 2 A or B here. Always air seal it well and test to verify.

  2. martyrg | | #2

    Hi Jon,
    Where is the Table you refered to? There wasn't a link in your reply.

    1. Jon_R | | #3

      Click on the word "here" in response #1.

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