Some of the Stokesley staff attended a seminar on Anhydrite screeds last week which was very interesting. We currently have a project on site that has an existing anhydrite screed. The area has been left fallow for about 6 years and we are now fitting it out as a ward. Please be aware that these screeds require a specific treatment before laying flooring, which involves scabbling or sanding of the surface and application of compatible primers prior to application of a compatible leveling screed which must be Gypsum based. It is also not advisable to traffic the areas being treated until the flooring goes down. This can have serious programme and cost implications if not planned ahead.
If anyone is carrying out a refurbishment project and is unsure of the screed type this needs to be investigated at the earliest opportunity to avoid potential delays further down the line, or use of the wrong flooring coating / adhesives resulting in defects.
If we are currently specifying this screed type in newbuild situations, we need to ensure that the maintenance regime is correctly documented in the health and safety file, as a client renewing floor coverings needs to be aware of the nature of the material.
 If anyone has experience of remedial treatment of this type of screed, I would be please to hear any useful information. We have come up with a specification form Uzin for this particular situation but it would be interesting to compare notes.