Porcelain Grout problems!!

[Bobalob23]

Any ideas what the best flexible grout to use is?
Or something to add to grout to make it more flexible?
Tiled onto a chipboard flooring with a ditra Matt over lay and grout has cracked!! 1mm grout joints

 

[Dave]

Is it on joists. ?

 

[Bobalob23]

Is it on joists. ?

I believe it was tongue and grove chipboard onto the joist then he had a heated Matt, levelling compound then a ditra Matt 🤦🏻‍♂️

 

[Dave]

I believe it was tongue and grove chipboard onto the joist then he had a heated Matt, levelling compound then a ditra Matt 🤦🏻‍♂️

Ok. Did you commission the heating slowly?

 

[Bobalob23]

Ok. Did you commission the heating slowly?

Wasn’t me who fitted work before tiling, I told them was incorrect I would always use backerboards? Think it could be because underfloor heating?

 

[Dave]

Wasn’t me who fitted work before tiling, I told them was incorrect I would always use backerboards? Think it could be because underfloor heating?

Could be thermal shock.

 

[Rae]

Sound like heating applied to quick and to high

 

[Bobalob23]

Sound like heating applied to quick and to high

Is this a common problem? Only cracked in kitchen not in hall

 

[Bobalob23]

Wasn’t me who fitted work before tiling, I told them was incorrect I would always use backerboards? Think it could be because underfloor heating?

Ok. Did you commission the heating slowly?

I wouldn’t imagine the heated Matt would been turned on for a couple of weeks after been fitted, is this a common problem?

 

[Dave]

I wouldn’t imagine the heated Matt would been turned on for a couple of weeks after been fitted, is this a common problem?

You are supposed to heat the floor slowly for its first initial time. This commissions the adhesive / grout etc without thermal shocking it.

 

[Bobalob23]

You are supposed to heat the floor slowly for its first initial time. This commissions the adhesive / grout etc without thermal shocking it.

Ok thanks I shall mention it, think it’s more likely to be from this and not though tiling onto ditra Matting on timber?

 

[Dave]

Ok thanks I shall mention it, think it’s more likely to be from this and not though tiling onto ditra Matting on timber?

That depends on deflection, was there excessive movement?

 

[Bobalob23]

That depends on deflection, was there excessive movement?

I wouldn’t say movement maybe vibration?