# Vapour barrier repair after large drywall patch ideas?



## RRH (Nov 24, 2016)

Leave it out. There was a time it was common practice to put plastic vapor barrier behind sheetrock.
They since found out it was a bad idea and it is no longer done.


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## Bud9051 (Nov 11, 2015)

Deep south and far north can still use a vapor barrier, but perfection (tuck taping) is not necessary. When you go to reattach the new drywall you will have a nailer on the sides. I like a backer board top and bottom if in the middle of a sheet. Those nail surfaces can be used to first attach your new vapor barrier but just staple it in place. You could add caulking if your OCD is kicking in.

When done it will be covered with a layer or two of paint which also serves as a vapor diffusion retarder.

Best,
Bud


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## Gary in WA (Mar 11, 2009)

If you don't tape the edges, or leave it out entirely, you may have problems. This is serving as your "air barrier" not vapor barrier, fig. 2; https://buildingscience.com/documents/insights/bsi-073-macbeth-does-vapor-barriers

ADA the drywall and go, may be easier to tape the holes, esp. if OSB sheathing.

Gary


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