O
Old Mod
If I remember rightly Schluter claim it can be tiled as soon as weight bearing . I stand to be corrected and if I was doing this I would obviously check .
The phrase they like to use is,
'as soon as its mechanically repairable'
Tape the joints for moisture sensitive stone, otherwise not necessary, but certainly doesn't hurt, personally I'd prefer it.
But yes as soon as its load bearing.
To fast track a screed a 'vapour equalisation barrier' must be used i.e.
Ditra 25
Durabase mat
These mats are not for wet ufh obviously, but they still do the same job as above.
Ditra E Heat mat
Variopro ufh mat.