A method for attaching an underlay element to a weight-reduced board element comprising a plurality of grooves, the board element being a panel per se or the board element being dividable into at least one panel, wherein the at least one panel is a floor panel or a wall panel, the method comprising:
- providing the board element, wherein a rear side of the board element comprises a groove portion and a remaining portion, said groove portion comprising said plurality of grooves, and said remaining portion being provided in a horizontal plane (HP) extending along the rear side of the board element, wherein said remaining portion is located on a periphery of the groove portion, each of said plurality of grooves being a recess formed from an essentially planar surface on the rear side of the board element,
- providing the underlay element, the underlay element being a foam or a cork sheet, wherein an upper side of the underlay element comprises a cover portion and a corresponding residual portion, which are configured to face and to be aligned with the groove portion and the remaining portion, respectively, when the underlay element is attached to the rear side,
- applying an adhesive on at least a portion of said remaining portion and/or on at least a portion of the corresponding residual portion of the underlay element, such that the plurality of grooves is free of adhesive during application and the adhesive fully circumscribes the groove portion, and
- arranging the underlay element on the rear side of the board element, such that the adhesive contacts the underlay element and the rear side, including between the remaining portion and the corresponding residual portion of the underlay element,
- wherein the board element comprises at least one layer, said at least one layer comprising a thermoplastic material, and wherein the plurality of grooves at least partly penetrates the at least one layer, and
- wherein the adhesive is applied at least on a peripheral portion of the rear side of the board element and/or on a peripheral portion of the upper side of the underlay element, wherein the applying of the adhesive is performed on at most 95% of said remaining portion and/or of the corresponding residual portion of the underlay element.