Help please, tiles cracked/moving

[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

 

[Andy Allen]

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

Even mosaics....?

 

[Steve doc]

There has to be more to it than just the tiles not being buttered I think as it looks like every tile has failed ,I haven't seen anything like this since porcelain first come out and some didn't use a flexible adhesive hence the non porous tiles not sticking to the adhesive . I would of thought a decent bal adhesive would of still gripped better than the picture shows.

 

[J Sid]

how much coverage can see ? 100% ? 75% 50% less?, no back butter, and skining over of trowled mix. Whatever suitable adhesive is used it will fail.

 

[Andy Allen]

Imo it's a combination of....

Sticking straight to ply...
Crap adhesive...
To much movement...( Especially with crap adhesive)..
No back buttering, with large format...

Either one or all of the above could of cause this problem....

I would now.....

Strengthen the floor to eliminate excessive movement...
Overboard with Hardie boards glued and screwed...
Tile using a decent flexible adhesive, like bal single part fastflex, or similar...
Back butter the tiles..
Grout with bal wide joint grout with gt1 admixture....or similar...

 

[Steve doc]

how much coverage can see ? 100% ? 75% 50% less?, no back butter, and skining over of trowled mix. Whatever suitable adhesive is used it will fail.

You can see the print of the tile in the adhesive obviously not complete coverage but I would of thought some of the tiles would of bonded it just looks to me as if the bond was broke possible walked on before completely set or adhesive skinned over .

 

[J Sid]

as Andy said, uncouple from the ply. Use a suitable adhesive and fix the tiles the correct way.
before the new ply is fixed, choose an adhesive you plan to use and fix ply as per there that companies instructions. Contact technical dept.

 

[Unused Account 1]

Use ditra on tiles,if bal came out and tileshevent been back buttered ,the blame is off them totally

 

[Balloo]

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

View attachment 106070

From what i can see the ridges from trowel have not even collapsed, its as though the tiler set the tile on the adhesive but didn't push it into the bed,, also the trowel he used looks about an 8mm trowel he should of used 15mm for a better contact,. But most importantly he should never have tiled on plywood as recommended by most adhesive companies.

 

[Andy Rhodes]

Glynn at tilemaster will tell you different Hsp101 flooring plywood (BS 8203:2017-Annex A is more than suitable to tile on

 

[J Sid]

Glynn at tilemaster will tell you different Hsp101 flooring plywood (BS 8203:2017-Annex A is more than suitable to tile on

it may well be if it's fix correctly as per BS
British Standard states
PLY
"The use of sheets and boards that are subject to movement from changes in moisture content should be avoided if at all possible."
"if sheet's and boards are not dimensionally stable with changing humility they should not used in wet or damp conditions."
"Tiles should not bridge joints in boards"
also
the lower face and edges of plywood should be sealed against the ingress of moisture using preferably non-aqueous sealers, e.g. polyurethane varnish, or styrene butadiene rubber, to prevent distortion by changes in atmospheric humidity before being screwed down.