Which screed would you recommend for wet UFH ?

[TC1973]

Hi folks,
Just looked at a conservatory tiling job. Wet UFH system, set into sand and cement approx 50mm thick. Fitted 2 months ago so should be cured. Heating yet to be commissioned. The sand and cement is dog rough, going to need prepping to level the floor ready to receive 500mm x 500mm porcelain. Been a while since I've done this type of floor. I'm more familiar with electric UFH, would normally use Mapei eco3210 over cables, then Weber PR360 primer with Norcross semi-rapid (flexi) adhesive. Never had a problem in over 14 years (touches wood). Would these materials be fit for purpose on a wet system, sand/cement screed? If not, what would you prefer ?
Much appreciated,
Tony

 

[Ajax123]

50mm sand cement with wet heating is not fit for purpose

 

[TC1973]

Thanks for the reply Alan. What should they have used? Any materials I could use to level then lay tiles or should I just walk away ? Much appreciate your input.

 

[Ajax123]

Minimum 65mm sand:cement or 50mm liquid screed