Vapor barrier material and tape

Old 03-11-21, 04:30 AM
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Vapor barrier material and tape

Iím in Long Island New York. I just re-insulated a room using rock wool un faced insulation. What material can I use for a vapor barrier ? Would 4mil poly sheeting be ok? Also what type of tape should be used to cover the seems ?
Old 03-11-21, 05:46 AM
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4mil poly is OK. I prefer 8mil just because I'm usually working alone and the stronger material can be abused more without tearing. There is vapor barrier tape most home centers carry it and it's 4" wide so you don't have to be as fussy about alignment as with narrower tapes.
Old 03-11-21, 07:58 AM
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You really need to make sure you are using the right terminology, vapor retarder vs vapor barrier.

Your local codes vary, check them out!

Personally I would never put any type of plastic Class 1 barrier in my house, you need to be able to control moisture when you have made the house like a piece of Tupperware!

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