I am trying to tile a 5' by 32" space above my tub. Unfortunately, the tiles are a little heavy and keep falling off. I scraped everything off and decided to ask for help. Is there an adhesive I can use instead of thinset? Should I rig something up with a board and a 2 by 4 to hold it up? I would very much appreciate any suggestions. Thank you!

If done right they will not fall, actually they will stick better than when setting tiles to the wall. If the tiles are large and heavy just be sure to trowel the thin set to the backs then push and slide them back and forth a little, them align. Slide the tile across the direction of the grooves to collapse them leaving no voids. You may have not applied enough or mixed the thin set too thin. Can you describe the consistency and tell use what kind of tiles you're installing, the specific thin set and size of trowel?

Jaz

Thank you Jaz. I back buttered the tiles and slid them back and forth like you said. The tiles are pretty big and heavy (porcelain that can be put on the floor) and we stood there with our hands above our head for over an hour because they kept popping off (before my post and your answer). The mortar was the consistency of warm/thin peanut butter-- maybe I need to mix it with less water? I was thinking maybe there were adhesives for ceilings... should I just mix a very small batch really thick and see what happens? Thanks for the advice, I really appreciate it!
Lisa

Take a thin screw and put a large washer on it. Screw into the ceiling at the edges of the tiles and the washers will hold the tile up until it sets. If you have really thin grout joints you may have to do only a few tiles at a time if you can't fit the screws between tiles.

I would mix the thinset(modified thinset for porcelain)a little thicker. When you back butter it and have the thinset on the ceiling it should form a vacuum when pushed together. You could rig up a piece of plywood and studs to hold it up un until set.

As already mentioned, the tiles will stay just fine (maybe better) as long as you apply the proper amount and the thin set is not too thin. There will be a suction created.

I do not recommend the plywood and studs idea. You'll mess up the alignment but won't know it until it's too late.

Jaz

If you push steady level pressure on the tiles while they are setting by using plywood and studs I don't see why there would be a problem if the tiles were laid right.I'm sure spacers are being used.

I agree with jaz... plywood with studs is not a method used.. pay close attention to the thinset and all will be good