Installing Beadboard ceiling

[Liz Wolf]

I tore out the plaster ceiling to install a beadboard ceiling. I though I'd take the lathe out little by little as I install the boards. However, the attic has blown insulation in it above the room. Would it be ok to put up a vapor barrier between the insulation and the boards? It would do two things, hold the insulation up until I can get the boards up and prevent moisture from damaging the wood ceiling. Someone told me the ceiling needed proper ventilation and the vapor barrier would prevent this. help!!! Any ideas or suggestions?

[Chris Fite]

I would leave the lath to provide for a level surface for the new ceiling as well as supporting the extant insulation. A vapor barrier generally goes between the living space and the insulation. Plastic sheeting attached to the lath will accomplish this. If you had batt insulation in the attic, the vapor barrier side would be placed against the ceiling. A better vapor barrier that will allow some transpiration is Tyvek.

Hope this helps.

[Rick Thom]

Liz, general rule is vapour barrier on warm side.
I presume you are planning to install something like 4" wide beaded boards that fit together using T&G. If that is the case, you are going to have a lot of joints and with seasonal expansion/contraction, good potential for them to open and close a bit leaving a 'stripe' of exposed surface the appears periodically.
If you are planning to paint the boards, I suggest you pre-prime the cut boards (all sides) and give them a light coat of paint (face side) incl T&G before installing. This will help to seal the boards reducing expansion/contraction and any tendency to cup, provide a colour coat should any of the joints open a bit later (they will), and also provides the equiv of a vapour barrier. They are a lot easier to pre-paint than after installed. I have had best luck with Zinn primers which are shellac-based to ensure paint adhears and knots or sap streaks don't show through.
Hope this helps you.

[Peter Mc Mahon]

Hi Liz. Tricky question. I too own an old house and have the benefit of a brother who is chief building inspector of the county I live in. Putting up a vapour barrier is a good idea on one hand. It will seal the moisture penetration if you use something like 6 mil poly [not tyvek which is an exterior house wrap] On the other hand though, the moisture is going to go somewhere [like your walls if they are not sealed well enough] so the dilemma is if you seal one area then the moisture is intensified in another. Personally I would install the vapour barrier. I would pre-prime the bead board as well as one coat of paint and then install it. Your ceiling does not need to be ventilated but your attic space does. Adding vapour barrier does nothing to promote or discourage this. Hope this helps Peter

[Maurice Ungaro]

Liz,
Since the plaster is already torn out, my suggestion is a bit too late - I would have left it in place, particularly if it was original to the house. That being said, leave the lathe intact. It will help attaching the beadboard, and if the next owner wants to go back to plaster, it's already up there. BTW, are you using actual beadboard, or 4x8 3/8 ply that simulates beadboard?

[Tyler Howell]

Welcome to the creek Liz. Great bunch of folks here.
I agree.

Leave the lathe
Vapor barrier (No Tyvek)
Vent the attic
seal the bead board both sides
Nail your boards not glue

We like pictures.