how do I attach ceramic tile to ceramic tile?
 

I have just finished tiling my tub surround with 3x6 inch subway tile but
the ceiling is not level so there is an uneven gap between the last course
of wall tiles and the ceiling. I thought to use a ceramic cove molding to match the trim in the rest of the bathroom but what are the best materials, thinset, adhesive to use to attach ceramic tile to ceramic tile?

how big is the gap?

How do I attach ceramic to to ceramic tile?
 

Hi the gap isnt even all the way along the wall..It is goes from approx 12/16 to maybe 1/16 at a pinch from the corner of the end wall of the tub surround
to the outside, at the back the gap goes from about 8/16 to 14/16 along
the length. I assume the gap at the plumbing end of the surround would
probably mirror the gap at the non plumbing end. I place the level up against
the ceiling and it seems to off by about the same amount at both ends.

It's all in the planning isn't it?:)

You could add another row of bullnose tile on top of the top row of wall tile and push the new row up to the ceiling. This would hide the gap and sort of decorate the top of the wall at the same time.

Or you could install tile to the ceiling thereby closing the gap somewhat and that should make the remaining gap caulk-able.:)

There are also plastic (lightweight) decorative trims that come in six foot lengths that could be used to cover the gap maybe. You could use any of the adhesives that are sold for installing outdoor decks or cement-block retaining walls.:)

Why is there a vertical-joint-line running up those walls?:)

How do I attach ceramic to to ceramic tile?
 

Hi bud...It isnt a vertical joint line...Its just marker pen. I have quite bad eyesight and I used the marker pen to mark out where to centre the tiles
for my next course. I had thought of using some kind of bull nose over the top of the existing tiles wasnt really sure what adhesive or thinset to use
as it is in a bath tub area. I found this rope twist trim that looks like it might
work, should I cope the inside corners( mitering doesnt seem to work, the
two pieces open up at the bottom when placed in the corner)

Got it! Had me goin' there for a while!:)

I wouldn't think moisture would be a huge issue in that area. Of course there will be moisture but not enough to worry about. You could scuff the surface of the tiles that will be covered with more tile and then use PL adhesive to install the bullnose.

That could be done also. Same adhesive should work in both cases. The Rope Molding you are talking about...is it ceramic or plastic? Rope Molding comes in several sizes if ceramic and comes in six foot lengths if it is plastic. Either would work but I think the plastic would be more practical for this application. It's all in what you like and want to do.

I don't understand why the mitering is an issue.:)

How do I attach ceramic to to ceramic tile?
 

Yep maybe mitering wouldnt be a problem. The plastic rope molding sounds
a good idea.Where can you get it from? I could cut it on my compound miter saw.

I see it here at Menard's all of the time but I think I have also seen at Home Depot. Don't know about Lowe's or Builders or the others.:)