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clarson
backer board of different heights

i was watching episode 3210. They were tiling a wall. The primary wall tile was a 8x24 ceramic tile and the accent tile was a glass mosaic. The two kinds of tile had a different thickness. So, they attached an additional layer of backer board where the accent tile would be going. This would result in the in the face of the tiles being flush once installed on the wall.
once backer board is installed the seams have joint tape applied to keep the grout from cracking. I would think having a step in the backer board resulting from adding an additional layer such as they did in the episode would result in a seam that would cause cracking in the grout.
So my question is whether anything special is preformed with the thinset or grout or anything else when this situation is encountered? And what would be done if the situation was a seam where backer board of different thickness meet?

dj1
Re: backer board of different heights

I install a tape embedded in thin set in all seams where cement boards meet.

HoustonRemodeler
Re: backer board of different heights

CBU manufacturers require all joints be taped and floated.

The method used is not one we would do. Its a ton easier to use one layer of CBU for the walls, install the 'field' tiles skipping over the inlay using a strip of wood in its place. Once the upper and lower field tiles are set, pull the wood blocking. You can make your own screed to float the thinset below the inlay to the exact depth you need.

Retroloco-LJ
Re: backer board of different heights

Perhaps in what you saw they had a problem in a shortage of materials or something else that was unforeseen causing them to use two different thicknesses of backer board. It's quite unusual since it honestly makes for more work. Yes you can create the thickness of thinset desired if need be with a self leveling material but it's easier to work with either a single board or boards of the same thickness. Yes all joints do need to be taped and sealed less you shortcut which could result in cracked tiles further down the road.

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