What is meant by porous and nonporous in relation to subfloors?
A porous substrate is one which is capable of absorbing water or liquid, such as concrete or wood. Liquid beads up on the surface of nonporous substrates which are typically existing resilient flooring. If there is any doubt as to porosity of the substrate, it can be checked easily by placing a few drops of water on the surface. If the water is quickly absorbed, the substrate is porous. If the water beads up and remains on the surface, the substrate is nonporous.
