Applying Microcement on Hemihydrate screed

playitagainsam

I understand that you cannot apply cementitious material on top of a hemihydrate screed (dries without a latience). There is some preparation perhaps that might create the necessary separation. I was thinking of using some sort of epoxy primer. Anyone have any guidance or suggestions?

Thanks

Mellor

Why would you be applying micro-cement over a hemihydrate screed?

Seems they would have very different use cases. My default would be either microcement over cementitious screed. Or if buildup a concern, the microcement could level a bit of unevenness in the substrate.

playitagainsam

Why would you be applying micro-cement over a hemihydrate screed?

The screed is not a workable finished floor. You need to apply your floor finishes (e.g. tiles, laminate, microcement). In our case we would like microcement finish in the bathrooms.

BryanF

Suggest the manufacturer/distributor/installer must comment. Ideally with evidence base case studies and data sheets etc. I’d imagine prep and primer would be really important + Moisture % of slab.

interested to know how you go. Please report back.

Mellor

https://www.boards.ie/discussion/comment/120932069#Comment_120932069

I think you are misunderstanding. I'm aware a hemihydrate screed is not a suitable finished floor. I'm asking why would you use a screed in that hemihydrate screed in this instance where you are planning a cementitious floor finish. It seem redundant, and sounds like its crating issues.

playitagainsam

I'm asking why would you use a screed in that hemihydrate screed in this instance where you are planning a cementitious floor

That's because when the screed was going in, I was ignorant about this issue. Only found out after.