Porcelain Tiles Cracking

[jonnyc]

did a porcelain floor just before Xmas .client calls me this week to say that tiles cut around external corners have cracked .been round and they have too even with ditra underneath . Anyone know why this happens . It is certainly not the first time . I really don't think I should be responsible for putting this right , these particular tiles were on sale at b&q but others in past have come from reputable tile suppliers

 

[J Sid]

The internal cut in the tile is to Sharpe, it becomes a stress point.
Ideally this should be a curved radius so any load or stress in or on the tile has no easy place to start if it wants to fail. The ditra has no effect on this I believe.
Hope that makes sense Jonny

 

[Qwerty]

Sounds strange!? Was it over UFH Jonny?

 

[Old Mod]

Hey Jonny,
Hope you're good mate.
Is it just tiles with an 'L' cut?
I had this few months ago, there was too much tension in the tile,
They broke, one after another, got a new batch, they were fine.
I was informed they'd been overfired causing too much surface tension.

Who's too quick now @JulianSidney! Haha

 

[jonnyc]

The internal cut in the tile is to Sharpe, it becomes a stress point.
Ideally this should be a curved radius so any load or stress in or on the tile has no easy place to start if it wants to fail. The ditra has no effect on this I believe.
Hope that makes sense Jonny

I get that it's a stress point but do you think it is the quality of the tile that causes this.it could be very costly if it happens few years down the lines and can't get replacements and I was blamed for the cracking . I wonder how I would stand if a client tried to sue me .?it has nothing to do with the tiling in my view

 

[Italy]

The internal cut in the tile is to Sharpe, it becomes a stress point.
Ideally this should be a curved radius so any load or stress in or on the tile has no easy place to start if it wants to fail. The ditra has no effect on this I believe.
Hope that makes sense Jonny

julian exactly.
pierce point intersection with milling cutter 10.8 mm

 

[J Sid]

I get that it's a stress point but do you think it is the quality of the tile that causes this.it could be very costly if it happens few years down the lines and can't get replacements and I was blamed for the cracking . I wonder how I would stand if a client tried to sue me .?it has nothing to do with the tiling in my view

I expect the quality of tile does not help, but as @antonio says, mill corner out to a radius or drill corner first with, say a 10 mm bit and cut to corner. This would be the 'material engineers' advice if you were to ask one.
This should done on internal cut on tiles, but who does it? I will use the grinder to put a radius in corner, lazy, yes! But have only had one go in may may years .

 

[Italy]

Tips to avoid cracks or broken in porcelain tiles already laid. - Tile Cutters and Tiling Tools Montolit

 

[J Sid]

Tips to avoid cracks or broken in porcelain tiles already laid. - Tile Cutters and Tiling Tools Montolit

Nice find @antonio

 

[jobdone]

Drilling holes in corners works the same on steel. Reduces stress and cracking. (Previous life was a stellar fabricator)

 

[Aston]

tiling, engineering, corner of windows and doors etc
Its all physics. Energy from pressure or impact will have reduced affect if it travels around a curve rather than sharp 90 degree turn.

 

[Chalker]

Same reason that brought these planes down.
de Havilland Comet - Wikipedia, the free encyclopedia

 

[jonnyc]

Thanks for the advice . All makes sense .i need to get up to speed on porcelain. So used to fixing stone for last 30 years and don't seem to have same problem .were now doing loads or porcelain and I guess that even though we know how to fix a dead flat rectified floor there are other considerations.

 

[Unused Account 1]

Everythings porcelain now,its getting ,harder ,as well ,have to learn about stress points ,guys on here will help ,

 

[Perry]

have seen it a quite a few times stone as well.