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Discussion Starter #1
I'm finishing my hobby room in the placement. The large part of the basement I'd finished and non finished areas are well insulated and already framed along all the external walls. R12 insulation based on what I can see. It's always very warm and dry thee.
The insulation (and frame with it) is covered with transparent plastic (polyethylene). Is that just to prevent exposed fiberglass insulation or it's a sort of a vapor barrier that I should keep when installing drywall?

Basically, the question is whether to remove polyethylene from the frame before installing drywall or keep it and install drywall on top of it.

Thanks in advance!
 

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I'm finishing my hobby room in the placement. The large part of the basement I'd finished and non finished areas are well insulated and already framed along all the external walls. R12 insulation based on what I can see. It's always very warm and dry thee.
The insulation (and frame with it) is covered with transparent plastic (polyethylene). Is that just to prevent exposed fiberglass insulation or it's a sort of a vapor barrier that I should keep when installing drywall?

Basically, the question is whether to remove polyethylene from the frame before installing drywall or keep it and install drywall on top of it.

Thanks in advance!
The plastic is a vapor barrier to prevent the normal room air humidity from condensing on the cooler concrete foundation wall behind. It may also be part of what holds the insulation in place.

Except if the foundation was painted with a (usually black) waterproofing on the outside, that is the vapor barrier and you may not have two vapor barriers on the same wall. THe lesser of evils is then to cut holes here and there in the plastic taking up perhaps 25% of the total surface area of the wall and then install the drywall panels over that. And run a dehumidifier from time to time especially in the summer when the humidity is above average.
 

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Discussion Starter #3
Thanks Allan. I looked underneath the fiberglass (there is about a foot of no insulation from the floor which is I understand is correct - so I have easy access).

There is two layers between the wall and frame/insulation. Facing the concrete wall/foundation is a black thin sheet of some material and I think that looks like some kind of vapor barrier. Then there is what looks like thick black paper or something paper based.

I think that these two layers represent vapor barrier between the outside wall and interrupt frame and etc. In this case, I shouldn't create vapor barriers on both sides of frame and insulation so I should tear that plastic off. Correct?

Thanks again.
 

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Discussion Starter #4
Actually, I've just had a chance to peak under the drywall of finished area and there is plastic so I'm leaving it as it is and will put drywall on top of that plastic I guess.
 

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Discussion Starter #6
Canada (Ottawa, ON).

Thanks for the link. At this point, I'm not in the position to replace fiberglass batt insulation (and potentially re-frame).

The house is about 12 years old and was built well. There is so far absolutely no moisture problem at any time of the year and I lived here for 2 years now.
 

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Vapor barrier. Leave it on the wall. Drywall right over top of it.

Edit: I am from Cape Breton, NS. We drywall right over the top. It's a 20 mil poly vapor barrier to be specific. Ensure to tape any seems with "tuck tape". About $12 a roll at any local building supplier.
 
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