In most cases the thickness of a Calcium Sulphate Screed will be less than conventional sand and cement screed. This can have a significant impact on storey height. The recommended thickness will depend on the category of use and whether insulation is present.

When installed directly onto a concrete sub floor unless there are unusual requirements, the minimum thicknesses can be as little as 30mm (unbonded) and 20mm (bonded). 

The table below relates thickness of FLOATING screeds and insulation thickness to the category of use as defined in BS8204.

When used to encapsulate underfloor heating pipes, the minimum thickness will allow for at least 30mm of cover to the pipes. This will usually result in an overall thickness of 55mm to 65mm.