At my wit's end, please advise - Tile Advice

[Sabina]

I had my bathroom done in September and my floor tiles have movement in them and the grout is constantly cracking. I'm at my wit's end as this isn't the only issue I've had with the bathroom and the builders have been back out several times to sort things out. Most notably a leak from the shower hot feed that was seeping down behind the tiled wall and along under the tiled floor, making itself apparent through stained water leaking up through some of the floor grout. They didn't believe my theory that the stained grout was due to a leak somewhere until the leak got even worse and started to run down a downstairs wall before Christmas. So this leak had been going on for 3 months until it was investigated and found.

Anyway, back to my floor. It was originally very creaky, (some uneven and moving), floorboards with lino over the top. Now it's the same floorboards with some kind of board on top, then underfloor heating, then tiles. When the fitters were doing the underfloor heating I popped my head in and asked if they'd managed to sort out the creaking/moving floorboards, and I'm sure the guy told me that the board they'd already laid on top would sort that out. Given they'd already by then started laying the underfloor heating and because I'm not the expert, I just left them to it and assumed/hoped they were right. Wrong.

My tiled floor now creaks when you walk on it and a couple of the tiles visibly move (see video). They've been regrouted twice already since original installation (most recently on 22nd December) but very quickly the grout breaks and comes away again. I know this is just going to keep happening.

The fitter (he's not a tiler, he got someone else in to do that part) has suggested taking the grout out completely and replacing with some kind of flexible grout, but from the little I've read so far, I'm not convinced that's going to fix the problem.

So, my question is, what, if anything, should I ask them to do to remedy this please? Does the entire floor (and therefore bathroom) have to come out to start from scratch? Or should I have been advised not to tile the floor when I have wooden floorboards? Is there anything I should be asking them about what they did to prep the floor? Eg. what board they laid, how thick it was, how they secured it etc? I'd really like to know what to say to them/ask for before I contact them again.

Thank you.

Areas where grout is cracking:

 

[Trigger]

Hi

Couldn’t play the video.

If there was too much movement in the floor originally you should have been advised that it is not really suitable for tiling.

If it has been re grouted twice already and failed I see no point in doing it a third time.

My thoughts are that it all needs to come and have floor strengthened or choose an alternative to tiles.

 

[Lou]

Hi There

I could play the video - I am using Chrome. The tiles look like you are pushing them down onto a spring! Oh dear - poor you.

 

[Sabina]

Thanks for your replies. I've told my builder I think the floor should be redone and will see what he has to say!

 

[Trigger]

Thanks for your replies. I've told my builder I think the floor should be redone and will see what he has to say!

Let us know the outcome. 👍

 

[bsc ceramics]

You need to find out what boarding was used and how it was fixed,
Was it plywood or a tile backer board (get the name of it) the grout
should already be a flexable one so find out what grout and adhesive was used

 

[Sabina]

You need to find out what boarding was used and how it was fixed,
Was it plywood or a tile backer board (get the name of it) the grout
should already be a flexable one so find out what grout and adhesive was used

Thank you, I’ll ask.

 

[mattconway1984]

If the original floorboards were old, creaky and had movement it's simple, they should have been removed. Then the joists inspected for movement and level, if not ok (I.e. bouncy/spongy), it would need work to reinforce or "stiffen it up" (that could be a major job depending on the construction of you house and how bad they are)....

Once the joists are ok (no movement and correct spacing) you can lay new floor boards using min 18mm ply. After that, a screed of Flexi adhesive under cement board (i.e. 9mm hardiebaker). Then your ready for tiles.

Note: you can also use ditra matting under tiles instead of the cement board.

 

[Slippery]

you can lay new floor boards using min 18mm ply

No point IMHO, better use 18mm cement boards or 18mm flooring with cement faced boards over. Ply will always creak as there is no way to bond the edges properly, tongue and groove flooring, bonded to floor joists (gripfill etc) and screwed, with pva glue on the joints will give a much better sub floor, You can also get tongue a groove hardie type board.

 

[Slippery]

...and yes, the floor needs to be taken up, you will never solve the springing tiles otherwise