I have a finished basement where the builder added a plastic vapor barrier between the fiberglass insulation and a suspended ceiling. It is stapled to the joists.

The problem is the vapor barrier gets in the way of maintenance and ends up torn (or filled with mouse debris). I recently installed a new circuit and needed to run the wire on the joists in the ceiling. I had to pull out a bunch of the vapor barrier.

Additionally - the suspended ceiling supports have to penetrate the vapor barrier. Does this mean it was leaky to begin with and likely didn't work anyway?

Since I have owned the house I don't think the vapor barrier has ever been 100% intact - and now it's even more so. Is this a problem?

  • What's above the basement? Normally, there's no good reason to have either insulation or a vapor barrier between two heated indoor spaces, but I wonder if there's something about your house that would make it necessary. Feb 4, 2018 at 4:10
  • The first floor of the house. The garage is attached but on a slab. I think at one point the basement may have been intended as an inlaw apartment, but for us it is a rec room.
    – cshimer
    Feb 4, 2018 at 11:03
  • Yeah, I don't see the point of this vapor barrier. You'd need one if the basement was vented to the outside, but if the basement is finished then it should already be sealed against outside air and moisture getting in. If it's getting in your way, just rip it out. Feb 4, 2018 at 16:05
  • There is a sliding glass door to the backyard. The front of the basement is underground, the back is exposed. But there is no direct venting.
    – cshimer
    Feb 4, 2018 at 20:34
  • If the space was unused in the past that might be a reason to have a vapor barrier but since it is your rec room I would not want it.
    – Ed Beal
    Nov 23, 2018 at 3:11

2 Answers 2


If the basement is finished and has no moisture issues, the vapor barrier is not needed. If it has moisture issues, the vapor barrier is probably a problem.

  • +1 for knowing a plastic vapor barrier is a problem. Good thing it was never very intact.
    – Lee Sam
    Nov 22, 2018 at 18:19

There is a very very very good chance that the plastic was only added to hold the insulation in - so it doesn't drop on the drop ceiling. It serves no purpose otherwise. Not really sure it would cause a problem either though. So poke holes in it or do whatever you want.

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