The subfloor on which the wooden covering, parquet or hardwood flooring is placed must be solid, load-bearing, flat as well as degreased and dust-free. If the subfloor is cement-based, it must meet a very important condition related to humidity. The required humidity of the cement subfloor, on which the parquet is installed, is 2%; with anhydrite screeds, a humidity of 0.5% is allowed. For screeds with built-in underfloor heating, these values should be reduced by 0.2%. The most reliable method of measuring the moisture in the subfloor is the CM method with calcium carbide, which should be done by a trained person with the appropriate tools, following defined procedures.
Alternatively, there are primers as well as types of adhesives that, with expert advice, can enable the installation of hardwood flooring or indoor strip parquet on subfloors with higher humidity than prescribed. This procedure should only be initiated after consultation with the manufacturer of the parquet to be installed. In its range of products Murexin has e.g. Special primer PU 5 with which residual moisture can be blocked even up to 3.5% as well as special modified silane-based adhesive (series X Bond MS-K) which can also be used on problematic subfloor.
The parquet is not cheap that you should ignore the importance of the subfloor on which you install this type of floor covering for your home.