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How to mend plastic sheeting under sheetrock?

marq9's picture

I posted the question to an old related topic:

So please reply there to not fork (posting here as well to facilitate finding the topic).

My house was built around 2000, and seems to have plastic sheeting behind the sheetrock (I'm unsure what thickness plastic was used and what type of plastic; is there some sort of standard?)

My house just recently flooded, and they removed the bottom 2 feet of sheetrock + insulation + plastic sheeting (which seems strange, given that their concern was that humidity would get to the insulation, which is what the plastic sheeting is meant to prevent).

What is the correct approach to get the bottom 2 feet of sheetrock re-installed? Should plastic sheeting be used for the bottom 2 feet? Is it ok that there will be a gap between the old plastic sheeting and the new one?

Additionally, the walls in our basement were completely ripped out, so I'm not sure what was there; should plastic sheeting be used behind the sheetrock in the basement?

(I am in colorado; we have frigid cold, dry winters)



There are all sorts of (post #212991, reply #1 of 1)

There are all sorts of thoughts, disagreements, and occasional fist fights over the proper "vapor barrier" treatment of basement walls.  I'll leave that for others to discuss.

In terms of the upstairs, assuming you have sheetrock/plastic/fiberglass, in that order, it should be possible for someone to tape a strip of plastic to the back side of the existing plastic (pushing the fiberglass out of the way as they do this).  It won't be perfect, but it should be pretty good.  (I'd consider just taping maybe a 4" strip up, then taping the full height filler piece to that, though you could attempt to tape in the full 2-foot height.)

Another approach would be to take about a 4" strip of thin sheet aluminum, slide it behind the plastic, and caulk the joint.  Then tape the new 2-foot plastic to the aluminum strip. (I'm thinking this is the scheme I'd prefer.)

In both cases you'd want to install new insulation first, before the plastic.

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville