Abstract: A floating floor comprises a plurality of square buffer members arranged in parallel at regular intervals on a supporting structural floor, a plurality of floor panels vertically spaced above the supporting structural floor by the supporting members to form an air layer between them. The floor panels are respectively provided with a plurality of air holes through which the air layer is communicated with the outside of the floor panels. The floor panel may be a hollow panel having a plurality of cavities extending in parallel in the longitudinal direction of the panel and being opened at butt ends of the panel, each cavity being communicted with the air layer through said air holes to form passages from the air layer to the outside of the floor panel. Instead of square buffer members, there may be used square supporting members and a buffer layer so that the floor panels are vertically spaced above the buffer layer by square supporting members to form an air layer between them.

Abstract: A floor panel for floating floor of the kind comprising floor panels elastically supported by buffer members laid on a floor framing is characterized in that the floor panel is provided with a plurality of through holes, and supporting means integrally united to its underside at proper intervals. The through holes are uniformly distributed over the floor panel and so designed that they have an upper opening diameter of 5 to 20 mm and an opening area ratio to the upper surface area of the panel within the range of from 0.1 to 20% to prevent the air between the floor panel and the buffer members from compression and expansion.

Abstract: A hygroscopic composite material comprising a humidity absorbing body having hygroscopic fillers in its basic material and a porous body having many micropores. This hygroscopic composite material retains its hygroscopicity for a long period of time by enhancing its humidity absorbing function by generating free water in the porous body and by discharging the free water.