My house was built around 2000, and seems to have plastic sheeting behind the drywall (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 drywall + 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 drywall 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 dryall in the basement?

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

1 Answer 1


The standard now is to never do that again especially if you use air conditioning. Building science has determined this was a very bad idea because it traps moisture within the wall cavity. Here's a little Building Science 101 on this issue... http://buildingscience.com/documents/insights/bsi-073-macbeth-does-vapor-barriers

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    I agree the plastic traps the moisture in the house. As we breathe we exhale quite a bit and with the houses that were tightly sealed there has been some mold issues. I would not put the plastic back up on regular walls. The only place I use plastic is on shower stalls to prevent the moisture there from getting to the framing & insulation.
    – Ed Beal
    Commented Apr 19, 2016 at 13:02
  • Thanks for the link Been There! Very helpful. However, according to the link, Wall 2b does seem to still be the standard; and especially as my house was constructed using Wall 2b and is simply being partially repaired, sticking with it instead of doing half one type of wall and half another seems the way to go. So how does one mend the wall if it's half cut out?
    – marq
    Commented Apr 19, 2016 at 14:41

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