hair line cracks on wall tiles

[spraggie]

I have just tiled a shower using rapid set Mapei cement and 150mm * 70mm white bonded tiles onto a soid ashlar wall. Having grouted with grey grout I can see that about 10 tiles have hairline cracks. Two of these cracks continue across two tiles so would dictate that cracks were not on the tiles before. I am going to have to replace them but am worried that the cracks may continue to appear. Any suggestions as to what caused this as I know the client will be on my case tommorrow!! Cheers.

 

[White Room]

Hi and welcome....you say ashler wall, the only wall like that is a rendered wall with lines cut into it so it looks like stone work.

 

[flaggy]

hi wot tiles are they are they ceramic ?

 

[ruairi mac]

Hi and Welcome. Could be wrong but are the tiles very thin? maybe the rapid set drying so quickly is an issue??
Or the fact that the crack continues across two tiles might suggest a joint line in the substrate?

 

[Dontiler]

It's most likely movement in substrate, take the tiles off and you will see crack in substrate, replacing tiles will not help,
you might have to overboard the wall
good luck

 

[spraggie]

Ceramic

 

[spraggie]

The tiles are 6mm. I was thinking the same as the tile cement was going off so fast maybe it was affecting the tiles. Should I have wetted the ceramic tiles on the back first?

 

[spraggie]

The wall was knocked off and skimmed over.

 

[spraggie]

I have taken one tile of and cannot see any cracking in substrate. The cracks are litterally on the glaze and do not penetrate through the whoe tile?

 

[Brian the Tile]

where did the tiles come from did you supply or customer?

 

[widler]

sounds like slight shrinkage has moved the tiles a tad,and just cracked the glaze if its not gone all the way through,could be a bad batch of tiles/glazing,
or like you say,maybe if you soaked them,could of stopped them drying out quicker than the setting of the addy

 

[flaggy]

sounds to me its the rapid set ,retile with ready mix addy

 

[ruairi mac]

Hi Flaggy don't like to contradict you but I wouldn't be a big fan of ready mixed adhesive, especially in a shower!
For me it would be tank the walls then just use a slow set cement based adhesive, would probably mean coming back to grout the next day but hopefully should leave you with no comebacks.

 

[The Legend; Phil Hobson RIP]

Sounds like crazing to me, this was a problem back in the day when tiles were fixed in sand and cement.

 

[widler]

but would crazing follow the tiles right across a few in a line which he said,which would prob be slight movement causing the crazing phil?