Tiling on New Screed

[Acton Andy]

Hi There,
I have just had a kitchen extension built and have a concrete floor, with wet underfloor heating and 100mm of screed laid a week ago. I am going to have stone tiles laid, the area is approx. 7 x 5 m. Questions:

1. How long should I leave the screed to dry out?
2. Do I need to use Ditra matting?
3. Do I need expansion joints?

Any advice would be welcome. Thanks to all of you.

 

[Dave]

Screed type ?

 

[Acton Andy]

Sorry I am ignorant on what screed type - it looked like a very dry mix that was spread over the area - but I am not a builder! Not much help!

 

[Chalker]

Welcome to the forum.
100mm screed with stone on top seems very thick!
basic rule would be 1mm per day, so 100 days!reslly need to know what screed was used first,mad some can be force dried after a few weeks.

 

[Lee@emctiles]

Andy, find out what from the builder what screed was used. Was it pumped? or is it a sand and cement screed?

Yes, a decoupler will need to be used, Q's re screed will then be able to advise on appropriate tile adhesive to use.

 

[Acton Andy]

Thanks for this. The screed is sand and cement, it was not pumped.

 

[Lee@emctiles]

A standard rule of thumb is 1mm a day upto 40mm, (longer if above 40mm)

Suggest that before tiling commences you put a moisture meter on the floor, UFh will need to be commissioned (turned on) and use an uncoupling membrane as you are using natural stone (depending on what type of stone used, may want to use a white adhesive to fix tiles)