Anyone tile over tile in a shower? Tips or regrets?

[Marian Smith]

I am considering tiling over tile in a walk in shower.  There is enough play in the Delta valve handle to accommodate another layer of tile and I have found drain extensions at HD.  Custom building products has a primer specifically for this purpose...but I was going to set the shower pan area with epoxy.  Anyone done this...and any regrets? Thanks.

PS. It is not a standard size or I would put In a cast iron pan.

[Will G.]

I think you would have to "rough up" existing tile surface to ensure good bonding. A cupped diamond blade on an angle grinder would do the trick (with a lot of dust) You would not have to go  completely nuts on existing tile just enough deep scratches for bonding and not lying awake at night wondering if a tile will fall off the wall and hurt someone. Also get the highest quality, most aggressive thinset available for setting the new tile. Besides that, check the peel and stick re tile mats.It's like a sheet of butyl adhesive that you stick on the wall and then stick new tile to the mat without thinset. There was a brand out a few years back that claimed you could tile over tile in wet applications but then backed off those claims. Was being sold at lowes when I looked at it but pretty expensive. Also some pretty cool looking panel kits being put out now, I saw some at innovatebuildingsolutions that looked nice (not just plain white) and would be super fast easy install