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View Full Version : Vapor barrier in ceiling?


ColinJ
Oct 28, 2008, 07:08 AM
My Kitchen has an old panel typed ceiling which I really dislike and is starting to show unevenness due to the old glue coming undone.

Plan is to just rip it down and replace it with drywall. However I have a question about installing a vapor barrier.. Right now it is just ceiling titles, then thin layer of what looks like cardboard and then blown insulation.
The house is one story with no venmar like systems.

What I’m thinking of doing is putting a vapor barrier between the insulation and drywall.. I think it would help in heat loss… But considered about moisture from the kitchen getting trapped between the drywall and barrier…

Suggestions?

rtw_travel
Oct 29, 2008, 09:33 AM
Looking from the top down, the theory is you have
1) a vented airspace above
2) insulation in the ceiling (R40 in our area, your area may be different)
3) vapour barrier on the warm side of the insulation
4) then drywall

There will be no moisture problems between drywall and vapour barrier.

Does the 'cardboard' have anything printed on it? Is it fairly continuous across the whole ceiling? That could be your vapour barrier, in which case you do not want to put a second one underneath it unless you remove the paper.

If you are taking the ceiling down anyway, this may be an opportune time to redo or augment the insulation.

EZHangDoor
Oct 20, 2009, 03:35 PM
Having a vapor barrier on the ceiling isn't required IF and only If you have the required attic ventilation. You can check with your local building department on the amount of required attic ventalation. Having one isn't going to hurt anything and the correct place to have it would be on the warm side of the insulation and under the drywall.