Tiled bathroom floor on chipboard has cracked!! please help

[andyandy]

I have tiled straight onto chipboard bathroom floor thinking ply was not necessary. The tiles have cracked along the chipboard join. It seems that the chipboard is NOT tung and grooved! I lifted the cracked tiles and the ones i think might crack.

Im really concerned to have to lift the whole lot to ply as of course id have to take out the sink toilet, boxed in waste. And raise the bath to fit the panel!!!!!!!

Is there any way/product/ combination of products i can use on the chipboard joins to stop them cracking the new tiles and of course not raise them above the tiles i havent had to lift????

Please help

Many thanks in advance Andy

[ultimatehandyman]

I don't think there is much you can do now apart from rip it up and start again.

[royaloakcarpentry]

Two options that I would consider, that mean you can leave the chipboard down and only raise the finished floor level by a minimal amount.

Ditra matting, which can be found on the web. I have used this previously after having it recommended. Never had any problems or comebacks after using it.

I haven't used this option but have seen it done before where a floor had too much flex in it. Wire mesh embedded into rapid set and then tiled ontop of. I know there were no problems with this either, but you must cover the whole area.

[DIY_Johnny]

and a flexible tile adhesive I asssume such as
BAL Flexible

Personally I don't like rapidset as I'm too slow and not in a rush but if you need to use the bathroom I can see why

[royaloakcarpentry]

Yes, you still need a flexi adhesive as well as a flexi grout.

Rapid set isn't a problem if you are too slow, you just mix what you can use. Same as normal powdered adhesive.