Heated Bathroom floor = cracked tiles ?

Some years ago we bought a new turnkey bathroom from a bathroom shop -(Think muppet show on skis) including an electrically heated bathroom floor. Within a few months the tiles (proper thick floor tiles) had cracked in a line right across the width of the bathroom. We called the fitter back and he changed the cracked tiles but because of all the grief we more/less stopped using the underfloor heating.
Spool forward 5 or 6 years to the present and we now have a serious problem with damp and black mould (see my posts passim about Pongos in the bathroom) and would like to try the heated floor again but daren't risk cracking the tiles, for one thing we no longer have the cache of replacement tiles we had last time.
Anybody know if there is any such thing as tiles rated for underfloor heating ?
DerekG

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I don't think your problem is your tiles, it's probably a water leak getting underneath them that's the problem.
Tim

I don't think that is the issue here, its the different expansion rates of the stuff the tiles are on, and the tiles. are you sure its the heating that has caused this, and not some structural issue of some kind?
Brian

On Thursday 10 October 2013 14:07 DerekG wrote in uk.d-i-y:
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They all are.
I *suspect* the installers failed to use a flexible adhesive and grout designed for floors with slight movement.
Could you insert a suitably rated rectifer diode inline with the supply to the floor, halving its power, and thus allowing it to run warm, but less hot?

On Thursday, October 10, 2013 2:07:16 PM UTC+1, DerekG wrote:
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No idea, but ISTR there is a maximum floor temperature recommended for wet (piped) underfloor heating. I heard of at least one job on which the sensor failed, or was by-passed over a week-end and the very expensive marble flooring had acquired a sawtooth crazy paving appearance by Monday morning.e

On 10/10/2013 17:17, Onetap wrote:
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I knew there was a max temp for wooden flooring over UFH (27 degrees is the oft quoted figure). I didn't know there was a max temp for tiles.

On Thursday, October 10, 2013 6:02:35 PM UTC+1, Piers wrote:
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And there's another one for bathroom floors, above which they are uncomfortable to bare feet.

On 10/10/2013 19:33, Onetap wrote:
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There's also a general one, as sitting with your feet on the floor above a certain floor temperature may increase your risk of deep vein thrombosis.
SteveW