If you have good ventilation and no small children who might decide to decorate with crayon, beadboard should be fine. We (our contractor, actually) put in beadboard when we redid our front bathroom four years ago and there has been no problem whatsoever with it.The BR originally had black and white tile that was cracked, chipped, and stained, an awful mess. When the tile came off, so did whatever was behind it, so those parts of the walls were down to the studs. I don't recall what our GC used behind the beadboard, but it is very solid and there hasn't been a trace of mold. We painted it a white that matched the Daltile that went up on the tub surround. To clean it, I use one of those mild kitchen and BR sprays - like Windex - and a slightly damp sponge every so often, but really, upkeep is no problem. For ventilation we have a jalousie window over the sink (original to the house, from 1933, not code today, but we love that window). I leave the window slightly ajar most days and that's all the ventilation we need. I think white beadboard would look lovely with your floral wallpaper, very cottage-y, one of my favorite looks. You could pick up the colors of the wallpaper in your towels and an accessory or two.

Marvelous! Thank you, dlbkelly_cfl_rr_com and the rest! I used Bostik Dimension diamond urethane grout which I’d used before with little issue, but I apparently waited too long to wipe AND since I had varying tile thicknesses this time -- I had the clever and time-consuming idea of combining 3 different styles/brands of tile sheets -- there was more residue to clean off. My glass -- regular, polished and frosted -- and stainless/polished steel mosaic tile looked horrid. Sadly, I used the manufacturer’s suggestion of Windex and that made the area’s grout I tested just a tiny shade of bluish white instead of brilliant white - only noticeable to me but still annoying. A half-vinegar/half-water concoction worked with the bulk of the thinner residue and I finished off the thicker bits with a razor blade/glass scraper (only on the glass); the glass scraper was necessary for the frosted glass tiles but I will go over it again with a pumice stone or magic eraser as was suggested elsewhere for matte tile. The brushed stainless tiles are giving me a hard time and the polished metal tiles did get scratched by the grout/ocelo no-scratch scrub and wipe sponges but a huge improvement! If this hadn’t worked, I’d have to run out and get the Bostik Blaze which is also good for urethane grout haze clean-up.

I had thought of the footprint - the house was built in 1983, so it may be an issue. Thanks for reminding me! We did buy extra tiles, but we were on an extremely tight budget at the time, so I know we don't have a lot. I'll have to count before we begin. I just wanted to see if it was even possible to do this, before having to come up with Plan B!

Ok, I follow what you mean now, brickeyee. However, I don't' believe this is an issue with Corian. After the tile is done, I had already planned to have the fabricator refinish the Corian countertop to remove scratches, etc. Corian is pretty impervious to this type of thing and I don't believe sunlight affects it like it might Formica. Also, if I do end up choosing to remove the Corian backsplash, the tile that would replace it would be very close in thickness (most travertine is close to same thickness as my backsplash)so I would be safe there as well. If it wasn't for some of the idiosyncrasies of my Corian backsplash install, I don't think I would run into these issues if I decided to remove it.