Why 4x10? If it's a seam/layout issue you can overcome that with carefull planning. I made all my cuts fall on one side or the other of the "bead", effectively making the cut look like a part of the bead detail. Not sure if you've considered this, but 4x10 is going to be a real PITA to lift and move around...MDF weighs a ton. Just a thought on the 4x10...why not call Nantucket BB direct and ask if they carry it. My guess is they'll probably say no, but you can then ask them if they've ever heard of it in that size. I've also got to think they've got a pretty good idea of what the competition does.

Use a primer-sealer and apply it on all sides, including in the tongue and groove, and do the same with one coat of paint. Allow to dry for a couple of days before installing, caulking where needed, and applying your final coat of paint. Beadboard plank will move with changes in moisture level and if you only paint it after it's installed, especially in summer, you will get small amounts of bare wood showing when it shrinks in wintertime. The primer/sealer and paint on the back side will protect it from any moisture that might get back there. Also add nailing strips above and below any electrical boxes or other interruptions; you will probably need some little square plastic thingies called receptacle extenders to bring the face of the outlet flush to the beadboard. If there's insulation in the stud bays, 1x2s set at the top, middle, and bottom of the wainscot area will smush the insulation less and therefore your maximum R-value is preserved, and a 1x2 still provides a good nailing surface. You only have to toenail it through the groove, you don't need to nail the tongue. A nail gun is a lot easier than a hammer and nails but you have to be careful not to split the side of the groove that you nail through. When you put your trim pieces on though, predrill them and use a hammer and finish nails as the trim pieces split easily, as I found to my sorrow. If you use an adhesive on the back and/or in the groove, use one that remains FLEXIBLE, because as the house shrinks and expands with the seasons it can and will literally rip the wood on the beadboard apart, causing cracks and splits. Most often it is the tongue splitting off the main board. The BANG! as the wood splits will scare the bejeezus out of you, and it invariably seemed to happen just as we were falling asleep! Stop every couple of boards to make sure you are level and plumb. Get a good long level, like a 4 foot.

I used a packaged, primed kit in our powder room. The kind that includes the baseboard, panels and top rail thing. For the most part, it was very easy to install. The section around the sink was hard, though, because the top of the pedestal sink is right in the middle of the chair rail. I had to kind of notch out the chair rail, if that makes sense. If I had known that going in, I wouldn't have used the kit and made the height 6 inches higher.

Laurie, I think that looks great! I can't wait to see the room as you progress. I love looking at the pictures of everyone's pretties. Oh I'm so happy that you enjoyed my pictures! I just googled "black toile bath" and "black toile bathroom" and then snooped the Images. So if you want to find any of that stuff that's how you can do it. Not sure about a shower curtain matching your wallpaper, but if you find a paper with matching fabric you can sew one. Another idea is to find the fabric you like, make a shower curtain from it, then use more of that fabric as wallpaper putting it up with wallpaper paste (but your walls won't be so scrubbable that way). Other options would be to shop for a different b&w shower cutrain. This one is a nice classic that will never go out of style -- White with Black Trim Or here is a Solid Black Curtain. Or, I really like this one. I have a weakness for pintuck satin. It's so classy. Black Pintuck Curtain. Here it is in a White Pintuck Curtain. I'd be very tempted to pick that one, but I'd put the bath together before I decided which.