Most older houses had no or an inadequate damp proofing under the masonry floors and walls in the basement. When low levels of rising damp rises up through the basement floors the moisture would evaporate faster then the rate of the rising damp and the surface of the floor would remain dry,
However, in a lot of basement renovations it is common to see laminate timber floors, carpets or lino placed over the original tiles floor and these new floor covering restricts the evaporation of the rising damp in the floors resulting in a build of of moisture and dampness under the new floor coverings. Over time this will result in the new floor covering becoming defective.
There are a number of solutions available to allow new carpets or timber flooring to be fitted in a basement, but before any of these remedies or considered the exact condition of the basement floor and damp proof course should be fully understood.