What to choose – cement or anhydrite screed in new buildings with underfloor heating?
We are faced with a choice: cement screed or anhydrite screed, popular lately. Now there are different opinions about it in terms of price, accuracy and thermal conductivity. If most claims are to be believed, anhydrite screed is much better at transferring underfloor heating heat. In a YouTube video, I saw just the opposite. What's right now?
I can only tell you what we used: Bathrooms: 60mm thick cement-based heating screed. All other rooms: Calcium sulfate base heating screed, 60mm thick. On top, we get tile everywhere.
With anhydrite, of course, it's easier.
I believe that with a cement screed you need more expansion joints, so it wouldn't be as nice in the living room, for example. But I would just leave the decision up to the professionals/building contractor.
A flow screed hugs the pipes better than a cement screed.
Cement in the basement and bathrooms. In other cases, anhydrite. This is usually the best way to go.