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frankoamerican
type of vapor barrier

I have a 2-story building that I will be using as a garage/workshop (NY). The 1st story is concrete block and the 2nd story is wood-framed with TYVEK and vinyl siding. There is no heat installed but may do that in the future. I have the opportunity to buy R19 fiberglass insulation for the 2x6 walls at a great price but it is unfaced. My question is - can I use plastic sheeting or maybe TYVEK as a vapor barrier for the 2nd story workshop? Or are rolls of kraft paper available? What would you suggest?

Sombreuil_mongrel
Re: type of vapor barrier

Tyvek is not vapor barrier; it is intentionally a vapor-permeable water shield that goes on the cold side of the structure, generally under the siding/behind the brick veneer. You would ant 6-mil plastic sheeting, with all the seams taped. and caulked at the floor line, directly under the drywall or finish.
On the block walls, I would apply a waterproof sealer on the inside. Will you furr-out the block and drywall?
The thing most people never think of is taking advantage of the inherent thermal mass of concrete block walls to moderate the climate in the structure. If you think about it, you will see that on a block structure, you want the insulation on the outside, where once the block is brought up to temperature in the winter, it takes a small input of heat to keep that mass warm, if you have prevented loss from the outside. That's why it's called "out-sulating".
S_M

Alton.cedric
Re: type of vapor barrier

You want to use an acoustical sealant as it will not dry. It is very sticky but remains glutinous. Make sure it is compatible with polyethylene vapour barriers. Do not use liquid nails or construction adhesive as it will not bond to plastic and just harden to the metal furring strips.

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