[task mistress]

My husband is going to put up some beadboard, 4 in pieces. He's going to stain and one coat poly before attaching.
My question is: should he poly the back too and be sure to stain and poly the tongue and grooves that meet?

He's going to let the panels sit in the house for awhile after the guy says they're ready to be picked up, would leaving the back uncoated allow the panels, after attaching with glue, to shrink and swell with the air humidity? Which is better for adhesion with the glue? (I don't think it's 'glue' but does the same thing)

We have never worked with this stuff and my worst nightmare is waking up in the morning and seeing all the beadboard hanging off the wall!:surprise:

 

[joed]

I would stain the tongues for sure so they don't show if the boards shrink with the season.

 

[BigJim]

We stained the face and edges then sealed all edges and surfaces. One word of caution when prefinishing them, be sure to wipe the excess off the tongues and out of the groves or you will have one heck of a time installing them. The reason to stain the tongues is so you will not see bright wood as the T&G shrinks.

If the T&G is 3/4 in thick, I would suggest using a trim gun and nail at an angle through the tongue.

Question, what is on the walls or ceiling where you are going to install the T&G? Chances are it is plaster, if it is the walls probably will not be very flat. It may be to your advantage to nail backer strips to the wall then attach the T&G to the strips, that way you can shim the strips straight and the wall or ceiling will be nice and flat. Also it will be much easier to attach the T&G to strips than to plaster.

If you do install backer strips you can use either a trim gun or a narrow crown staples to install the T&G, also using construction adhesive always helps but not a lot over loose plaster.

 

[joecaption]

Why the narrow strips?
Whole lot faster and easier to use birch bead board and far less gaps to has to deal with.
What's it going over?

 

[1acre]

the boards may shrink and swell, but it wouldn't be because you skipped the film finish on the back. I wouldn't waste my time putting poly on the back of the boards. It also is a poor surface for some paints/stains to adhere to. Not sure what glue you are using, but the poly may also prevent the glue from doing it's job.

 

[123pugsy]

I believe that poly on the back as well will help the boards from cupping.

Construction adhesive will have no problem sticking to poly.

 

[1acre]

I disagree that poly will help to prevent cupping in this situation. That's solving a problem that is highly unlikely. And if you have cupping of wood, you have larger problems than where you applied a single coat of poly. Jmo.

 

[joed]

The only reason for poly is vapor barrier. It could even make cupping worse by causing the board to dry uneven when humidity changes.

 

[Zero Punch]

since moisture will enter and escape from the cross grain cuts there is no need to poly the backs of the boards. If your home is kept in normal living comfort temp and humidity I wouldn't worry about extreme swelling or shrinkage.
What you want to do is allow the b board to acclimate to the area it is to be installed in. The same as you would for T&G flooring. This 1/2 x 4 wainscot was all stapled to the drywall 1 in narrow crown, no adhesive. Benn up 15 years with no loose or buckling.