CA flow screeds must be abraded, vacuumed and, as with all calcium sulphate substrates, primed with ASO-Unigrund. The moisture content of a calcium sulphate screed must be determined with a carbide hygrometer before installing finishes. If ceramic tiles are to be laid on calcium sulphate screeds with higher levels of moisture than those given in current regulatory works, a max of 1.5% for unheated screeds and 1.0% for heated screeds can be accepted.
NOTE: Ensure that there is no rising damp coming from the substrate. This type of installation does not comply with the generally recognised rules of technology and must be contractually agreed separately.