First Time Limestone Floor - TilersForums.com

[Stef]

Tom go on the Schluter course you may be surprised as what you could learn there.
The guy that designed Ditra realised how tiling of old had lasted as long & that was to decouple it from the ground with a layer of sand.

 

[Camper]

If the screed was installed properly it already is decoupled (With styrofoam sheets instead of sand). With or without Ditra you still need to install movement joints. This is the reason for the cracks in the pictures above ( NO movement joints).

 

[Bill]

Tom go on the Schluter course you may be surprised as what you could learn there.
The guy that designed Ditra realised how tiling of old had lasted as long & that was to decouple it from the ground with a layer of sand.

Not all did that. I have fixed onto suspended timber with sand and cement and had no problems....it is how you fix them that matters. I wish we had mobile phones 30 years ago that took photos!

 

[Bill]

Sorry I have no before or during photos but here is one I did not long ago...soft as turkish ceramics..... no decoupler fixed in sand and cement onto a concrete base......

 

[Stef]

If the screed was installed properly it already is decoupled (With styrofoam sheets instead of sand). With or without Ditra you still need to install movement joints. This is the reason for the cracks in the pictures above ( NO movement joints).

"If the screed is installed properly"
If every screed was fitted this way then there would be no problem, that's where the decoupler comes into its own.
My pictures above are nothing to do with a movement join not being fitted.
No run is more than 3m long & is broken across the door ways, it was a badly fitted screed.

 

[Stef]

Sorry I have no before or during photos but here is one I did not long ago...soft as turkish ceramics..... no decoupler fixed in sand and cement onto a concrete base......

View attachment 81781 View attachment 81782

I'm not on here for an argument but I would like to see that floor in a years time.
As stated "If" the screed is installed correctly there shouldn't be an issue.

 

[Spud]

That looks really nice Tom

 

[Camper]

"If the screed is installed properly"
If every screed was fitted this way then there would be no problem, that's where the decoupler comes into its own.
My pictures above are nothing to do with a movement join not being fitted.
No run is more than 3m long & is broken across the door ways, it was a badly fitted screed.

It's true screed is rarely fitted by code. I suspect the reason for this is ignorance and/or price/time pressure.
However laying a decoupler just because it's stone and we have an anhydrite screed is also not code. This is my disagreement. It's not a prerequisite for a properly installed floor. Furthermore the decoupler is not a replacement for movement joints. Without movement joints your stone will crack even with a decoupler.

It is paramount that the OP inspect the screed, and have all issues rectified before laying the stone. And that all movement joints are kept intact and functional after the stone is set. This will ensure a long lasting floor.

 

[Flintstone]

Would you still insist on decoupling on an old screed that's been down many many years and still fine, maybe an origional concrete floor?

 

[Flintstone]

Stef, that floor is knackerd anyway no Matter what your fixing to it.