Cracked porcelain

[rj1884]

Hello. I've uploaded some photos which I hope you can see of a job I've just been to look at. Cracks like the ones in the photos have appeared in various places in a large entrance hall in this house. The crack doesn't follow one line and some are in and around the door threshold/frames and some Randomly in the middle of the floor. The tiles are porcelain as in photo 4.
the house was built 4/5 years ago and the tiles are fixed to screed which has UFH pipes running through it. I've looked around the perimeter and it seems grout has been used in the expansion gap from floor to wall.
From your experience what would have caused these random cracks as I'm going to be removing the cracked ones and fixing new ones.
thanks in advance

 

[White Room]

Was any decoupling used....and how long have the cracks been there.

 

[steve187]

Joints look small, i would think some cracking in the screed.

 

[Ian]

I'd say settlement cracks. I think the cracks will follow into the screed when you lift the offending tiles.

 

[Houston]

lateral movement in screed

 

[rj1884]

Thanks for your replies. I asked about the decoupling mat and no matting was used which I was surprised about. Not exactly sure when the cracks appeared but i'd say they are recent. i would suggest the joints are no bigger then about 3mm.
I'm hoping that there's limited damage to the screed after removing the tiles

 

[area tiling]

Settlement cracks in the screed !

 

[Chalker]

Tiled onto uncured screed.

 

[jonnyc]

The cracks do follow from one tile to adjoining so you can guarantee that the screed underneath will have a crack in it the same .how do you propose to stop the new tiles you fix from crAcking again

 

[rj1884]

Thanks for your replies. In relation to repairing the screed what would you guys do bearing in mind it'll need repairing with the good tiles in situ. I'm open to suggestions. I can't lay any matting as this would raise the height of the new tiles. Is there anything else you would susuggest.
many thanks

 

[Ajax123]

Pound to a penny if you lift the tiles the screed will be cracked following the same line. This means the screed has become unsound and should be repaired. Unfortunately it is not as simple as that if the screed has no joints across door thresholds and the like repairing it will probably just lead to the cracks moving and rebreaking. I think your best bet is to repair them as best you can using a flexible epoxy resin to help reduce any vertical movement then replace the tiles with an uncoupling membrane. I don't think this will give you much choice.

 

[rj1884]

Thanks for your reply. Putting a membrane down would cause problems with height I assume when fixing the new tiles down.

 

[Qwerty]

Thanks for your reply. Putting a membrane down would cause problems with height I assume when fixing the new tiles down.

Very little extra height...... roughly 4mm higher

 

[rj1884]

Hi. Just spoke to the guy again and he said that the first crack appeared soon after the house was built and have kept appearing upto about a year ago.
Also what would be from your experiences the best way to remove porcelain tiles in this situation.
Many thanks

 

[AliGage]

What area is there in total? I think i would be approaching the subject of a complete rip out, repair, decoup and fix.
If the cracks have been appearing ever since built there is no guarantee that after repairing the ones evident at the moment that more won't appear.