Grout joints cracking

[Mattash99]

The wet side has been left on, as the floors are they're only source of heat for the kitchen/diner, i did think of that possibility, but the cracks have spread about 5 linea metres from the joint and not all over the floor, probably still 70% of the floor, but not in continuous joints

 

[cam_low]

Bri has expanded (lol) on where I was going. My money is on the new screed expanding and causing the slightest pressure... Just enough to crack the grout maybe?

 

[Stef]

The mat supplied by the spark, was it for a timber or concrete floor?
I got sent down the wrong mat for a floor before but I'm not sure what the outcome would be as I never fitted it, got it exchanged.

 

[Mattash99]

Enough pressure to crack the grout, but not enough to move the tiles, maybe, you think that would move that much over 5metres without any hairline cracks appearing the tiles?? Cheers for all your help by the way

 

[Mattash99]

I'm guessing they got the right mat, doubt they'd own up to it now, but that's one thing I'll check up on

 

[Ajax123]

Only reason for grout cracking in this type of floor makeup is movement. Something is clearly moving. What are the floor dimensions. Is there any hollowness in the tiles especially round where the grout crack are. I agree with your suspicion about the 100degrees C although I suspect that is a bit of an exaggeration. It has just got really cold so have they put the heating on at a high temperature causing rapid thermal expansion and thermal shock?? Is there expansion gap around the edges of the floor. If not it could be trying to belly upwards breaking the grout as it goes.

 

[Mattash99]

Alan, something is definitely moving, just can't figure out what is doing it. The tiles are solid around where the cracks in the grout are, there is some form of expansion round the edges as they are under the units and from memory they weren't cut in tight to the walls. It was a slight exaggeration regarding the temperature, but it was extremely hot, it is basically cracked where all the matting is and I guess it's gonna come down to the heating system, is there any way on an electric system to check if it's been used, other than the tiles being hot!!