Help please, tiles cracked/moving - Tile Advice

[Pablo68]

Hi everyone,

I’m looking for a bit of help please.

My house was a new build 18 months ago and we paid the builder extra to tile the first and second floors with polished 600x600 porcelain tiles as our previous house had these on the full ground floor with no issues whatsoever.
All was okay for six months or so and then some of the tiles started to crack and move, fast forward another six months and probably about a 3rd are moving/cracked and lots of grout missing.
The builder has been out to inspect them along with their tiler and a couple of representatives from Bal whose products were used but they are of the opinion that the products aren’t to blame!
The builder has agreed to go ahead and rip out all the old tiles to replace with new along with the plywood 25mm? They were laid on.
When they have lifted the tiles the adhesive appears to be firmly stuck to the plywood but none of it has come off with the tiles so to me looks like it hasn’t adhered to them hence them all moving/cracking.
Could this just be down to them using the wrong adhesive? I don’t want them re-doing this for it all to happen again 6 months down the line as it’s taking over 2 weeks for all the work to be re-done and we certainly couldn’t afford to have it re-done again!
Any help would be most appreciated.

TIA

 

[Andy Allen]

Shouldn't tile straight onto the ply, cement boards are a better option.

How much deflection is in the floor, does it move up and down alot ?

What adhesive and grout was used?

 

[Steve doc]

Generally cracked missing grout is because there is movement in the sub floor and new builds often shrink and move ,if their re tile insist on ditra matting layed between the play and tile.

 

[Steve doc]

Ply and tile

 

[Flintstone]

Can you lift a couple of tiles and post photos please

 

[Pablo68]

Here’s a picture of where the tiles have been lifted.

 

[Steve doc]

It looks like the tiles haven't stuck to the adhesive!, Possible they didn't use a flexible adhesive

 

[Dumbo]

There are issues there with the tile not bedding properly. But if was a betting man I would put main cause of failure but no the only cause as a lack of back buttering the tile before laying . This helps the tile stick to the adhesive that is on the floor.

 

[Steve6690]

I'm new to this game but IMHO poor troweling out and a lack of back buttering has caused this or certainly contributed in a big way. I start tomorrow on a 28 sqm 600 x 600 porcelain floor (my own) so this thread has given me useful info.

 

[Chalker]

I would say poor trowelling technique, no back buttering and adhesive mixed too stiff, or starting to go off.

 

[Bathfix Bob]

Builder went for speed and not quality by not back buttering, tut tut..anyone can spread addy and plonk tiles down but he needs to back butter and collapse ridges.
He will now pay dearly, an expensive lesson ...

 

[H573]

So on flooring, should you always back butter?

 

[Dumbo]

No , but tiles above a certain size should be and 600 x 600 should be
.

 

[J Sid]

I think it's good practice to back butter all tiles

 

[H573]

Cheers, much appreciated