Mama,
Google Flexible, natural stone veneer. It's not bathroom tile like you are thinking, but, I know this would easily go over what you are thinking about.
It's totally water proof, natural stone, and when you look it up, you will see it can be cut with sissors!
Just a thought for you.
It would be alot easier to use that, and you could pick what natural stone you like.
It is natural stone, just real thin so its easier and cheaper to work with.
You may have to contact the company who makes it to see where you can buy it where you live.
If you don't like the idea of stone, there is always that board they sell at big box stores that looks exactly like tile that you want, and you could put it right over your MDF.
It would be very water resistant and give you the tile look you want.
But to answer your original question, NO. You have to tile on cement board. For real tile, you have to rip it all down, and install cement board, and tile on top of that.
Sorry.

I disagree, you do not have to tile on cement board in an application like this. We're talking *one single row* of thin, lightweight, small tiles for a decorative backsplash, not a huge wall of tile! You can do single rows of tile on good-condition drywall using thinset. You can add a moisture barrier if it's a high use / wet area.

A thin sticker-like sheet of stone is definitely not the look we're going for, plus I imagine it would leave weird gaps with the beadboard grooves. And there's no way I'm buying an awful sheet of that cheap tile board to cover my gorgeous beadboard with. We're talking one single row of tile, here, did you misread my post?

I called a couple of tiling professionals I know and have worked with in the past. They said cement board would be complete overkill in my application which is just a 3" high strip around my small vanity.

I saw the two tile guys at church this morning, and they gave me these instructions for tiling a single decorative row over painted MDF beadboard, and said it will work for tiling over regular wood beadboard as well. So here is the info if anyone else is looking:

1. Make sure the beadboard is secured to the wall properly, you don't want to tile over loose beadboard. Also inspect the beadboard to make sure it's in good condition. No warping, mold, peeling paint, or anything of that nature.

2. Lightly sand the area and wipe clean.

3. Trowel on pre-prepared thinset mortar for small projects. Fill in the grooves of the beadboard with the trowel, and smooth it out. You can use a moisture barrier membrane at this point.

4. Let it dry over night. Apply the tiles by 'buttering' more thinset on the back of each tile and pressing to the wall. After it's dry, grout as you normally would, and seal the grout.

They did agree with me that grouting neatly with those ridges / grooves in the beadboard will be a bit tricky at the top, and thought taping off with painters tape was a good solution.

Anyway, maybe it'll be a disaster, and I'll come back to eat crow butterfly, but I'm definitely trying these instructions.

When I tiled my kitchen counters and backsplash in 1976, I didn't know any better and I used tile adhesive to glue 6" tile to the plywood that I waterproofed with Thompson's water seal. That tile and the 1/4" grout stayed put and even went thru the '89 quake here w/o cracking. It was in perfect condition (but looked SO dated) when we remodeled and put in soapstone counters in 2005.

I'm currently making a decorative box to hang over our toilet...I am gluing 1/2" mosaics to the wood. Weldbond glue works with anything, porous or non-porous. I don't think you have to mess with thinset if you don't want to, but you do need to fill those grooves...spackle?

I agree that is is a decorating thing, won't see wear and tear.

-Babka

Thanks so much Babka. You're right, the initial thinset is probably just to make the flat surface. I'm going to experiment on some scrap and I'll definitely try this. Thanks so much for chiming in.

I personally do not like the idea of putting any sort of liquid on mdf, including thinset.

Maybe glue would be better then, though still a liquid. It is primed and painted with latex, and no raw edges are exposed -- you know where the fibers can soak up water and swell?

The test pieces I've done today look great. Allowing to dry overnight.

Oh - should have mentioned. I did two test samples. One with thinset, one with some glue the tile store recommended. One more has a moisture barrier painted on first. All look great.

I lightly sanded the latex paint first, and one one sample filled the grooves with spackle, sanded smooth. The other, I filled the grooves with thinset, and did a whole covering, smoothed. The spackle is less labor intensive. So far I don't see any difference in bond and none of them are swelling or bubbling in anyway.

I think I'd be nervous if I were doing this near an edge. We used to have the MDF beadboard resting on top of the baseboard, and even sealed with silicone, water got in that crack over time and the beadboard swelled. Now all raw edges are sealed with paint, and are beneath all the trim work, with the line of silicone caulk sealing the crack.

Your install is not a critical area like a shower wall or traffic floor area. You will be fine.