i need to raise my concrete floors by 10-15mm & have looked at chipboard/ply & underlay options & am now considering screed, is this too thin for a screed? will it crack being so thin against the original concrete floor beneath? am hoping to use finer sand in the mix for a smooth/level finish, by the way what is the mix for such a thin screed? 3 sand : 1 cement? i'm going to do 1 room at a time, 3 rooms/50sqm in total, any advice?
thx.
alex.