swap out bath wall tiles: re-tile or remove backerboard

NJoytheRide

Ok, title is simple enough, but again:

my fiance wants to swap out our bathroom shower/tub wall tiles from 8x6 ceramic blocks to glass mossaic 12x12 tiles.

After I remove the ceramic, do I NEED TO REMOVE/REPLACE the concrete backerboard OR can I just RE-THINSET OVER THE OLD THINSET and put up the new tiles?

Other posts here on the forums kind of elude to full replacement, but none come out and directly say it.

I have been watching many DIY videos on YouTube and HGTV, and DIY Networks TV website and I have not found the answer. I saw on a "Bathtastic" episode on DIY network that Matt Muenster just sawzalled the entire backerboard with tiles still attached out of the wall and started new.

I don't want to have to do that if I don't need to.

Please DIY Obi-wans, you're my only hope...

Ron6519

You will take everything off the wall, not just the tiles. It could be sheetrock or cement board, but it will all come off. You will then reinstall a new cement board, and tile the wall.
Ron

Grampa Bud

Ron's got it. 12 X 12 tiles are generally 1/2" thick, very heavy and require a 3/8 -1/2" mud bed to hold them, NOT thinset. Removing 8 x 6 ceramic tiles will destroy the backerboard-cementboard anyway so stripping the walls to the studs IS the only way to go.

J S Machine

I agree.

Trust me, you will probably not get the old stuff off without bringing everything with it.

Need to use cement board as a backer to go back in there.

tandj1997

+1 (all answers are true)

Blondesense

True. If it was done right, it's all gonna come down. If it was done wrong, you're gonna want to take it down.

While it is true you want cement board underneath, there is more to properly building a shower surround than just CBU, tile and grout. Here's a start:

http://www.diychatroom.com/blogs/con...wer-walls-152/

If you haven't dug around and found them yet, there are two sub-forums here, one on Kitchen and Bath remodeling (under remodeling), and one on Tiling (under flooring) you might want to take a look at. They both have a lot of good info.

NJoytheRide

Thank you folks, I went out and bought all of my supplies today. If I run into a snag, I'll be sure to ask here.
Jams

NJoytheRide

One more thing, there is a recessed light in the tiled ceiling in the shower/bath that has a foam insulating ring around it; what do I need to do when I replace this surface with the cement board?

Ron6519

You can leave it alone or replace it with a moisture resisttant material. It doesn't need to be cement board.
If you want cement board, just cut a hole in it as you would sheetrock.
Ron