Calcium sulphate screeds have become an increasingly common choice of subfloor to install in new builds, especially where underfloor heating is incorporated within the subfloor. This is because of the speed with which they can be applied over large areas and other advantages over concrete bases, including less shrinkage and fewer joints required within the subfloor. Neil Sanders, Technical Director at F. Ball and Co., gives his advice on achieving a long-lasting, professional flooring finish when working over this type of surface.