Cracks in travertine tiles laid on Gyvlon screed over UFH - Tile Advice

[Pauline V]

Heeelp!!!
I've seen some old posts about this but nothing recently.
I have 120sqm travertine over the whole of the ground floor. It was laid over wet UFH and Gyvlon screed about 12 months ago.
Cracks started appearing about 5 months ago and I now have cracks in MANY places - both across thresholds and some within rooms across multiple tiles. They start as hairline but widen over time. On some, the tiles are lifting either side of the crack. I do a regular inspection and new cracks are still appearing.
My questions are:

• Should my builder have used a decoupling membrane?
• Is there any solution other than taking up the whole floor?

In utter despair (
Many thanks
Pauline

 

[Dave]

Hi. Any pics. also what preparation and adhesive used. Was heating commissioned before tiling.

 

[Pauline V]

Hi. Any pics. also what preparation and adhesive used. Was heating commissioned before tiling.

Thanks for getting back Dave
I've attached several pictures - these are a few of the many.
I understand the Gyvlon should have been mechanically sanded but it wasn't. It was primed with Tilemaster Prime Plus and the tiles fixed with Anhyfix.
Having now read about UFH commissioning, I'm not sure this was done. It was turned on at the lowest setting after my builder was told the moisture level was right for this - that's all, no other process.
Many thanks for your help
Pauline

 

[bsc ceramics]

Because the cracks are going through a few tiles in a fairly straight line its likely
the slab has hairline cracks in the same place. an anti fracture mat would have helped in this
also expantion joints. And if the the prep was not done with the screed then you may have more problems
in the future. Contact the builder and see what he has to say. As a temp fix try grouting the cracks with
some limestone grout. Let us know how you get on

 

[Pauline]

Many thanks Dave - I feared that was what you would say.
Much as it gives me shivers even to think about it, is the only permanent solution to have the whole lot up?
Pauline (

 

[Dave]

Many thanks Dave - I feared that was what you would say.
Much as it gives me shivers even to think about it, is the only permanent solution to have the whole lot up?
Pauline (

It looks very likely that has to happen. Cracks in tiles tend to be stress related in some way. It’s basically looking like its poor preparation and knowledge of what is required for a heated screed.

 

[Pauline V]

It looks very likely that has to happen. Cracks in tiles tend to be stress related in some way. It’s basically looking like its poor preparation and knowledge of what is required for a heated screed.

Many thanks Dave
I'll take all this up with the builder
Pauline