Wet room, cement on top of Anhydrite screed - Tile Advice

[Adam18Spring]

Hi guys
Long time reader and lurker, got so much great advice...

Quick question, i have a Anhydrite screed currently that was put down in a wet room (Wet UFH 50mm thick) it is currently 50mm lower than the finished floor height needs to be.

My question is, would it be the following buildup be suitable:
1: Prime Anhydrite with BAL DPM

2: Apply adhesive BAL Rapid Set with uncoupling membrane BAL Rapid-Mat

3: Build up to just under the finished floor level with sand cement screed incorporating my falls to the linear drain

4: Tanking ontop of the new concrete (BAL Tanking kit)

5: Tile etc

Thanks
Adam

 

[Flintstone]

Perhaps ring bal themself Adam and ask them to spec it. Could you not stick a 50mm insulation board down and kill about 3 birds with one stone ?

 

[Adam18Spring]

Thanks for the reply, I did consider that option but don’t want to lose the underfloor heating in the room. I have sent BAL an email as you suggested and will post there response when I get it

 

[Ajax123]

What's the uncoupling membrane gonna do? Seems an unecessary expense and quite a lot of messing abot. Why not just use a 500gauge polythene membrane and 50mm fibre reinforced 4:1 sand cement screed. Make sure you tank the room properly before tiling