The substrates must be cured and sufficiently dry, mechanically strong, free from loose particles, grease, oils, paint, wax, etc. The cement substrates must not be subject to shrinkage after installing the wood. The moisture content of the screed must be lower than the maximum prescribed by the parquet manufacturer. It is necessary to check moisture content throughout the entire thickness of the substrate, using a carbide hygrometer. During spring and summer, renders must be cured for at least one week for every centimeter of thickness, and cement screeds must be cured for at least 28 days unless they have been made with DCI special binders for screeds such as Screed 80, Level S10, or with Level S30. In case of floating screeds over insulation or light weight layers and slabs on grade must be provided with a vapour barrier to prevent rising damp. Existing ceramic tile has to be thoroughly clean and degrease before proceeding to bond. Adhesion of the flooring may be improved by applying a layer of Primer EPPU as adhesion promoter prior the installation. In case of old wooden floors has to be make sure that the planks of the old floor are well-bonded to the substrate. Remove any varnish or wax from the surface of the floor with sandpaper down to a bare wood finish and remove all dust with a vacuum cleaner. On anhydrite substrates the surface must be sanded and primed with Primer PU or Primer PU Fast