Knauf T&G Boards HUGO18. These are medium density gypsum fibre panels engineered with tongue & groove edges for ease of installation requiring just Knauf single layer joint adhesive to create a monolithic robust surface: No screws required. Panels require full support over a flat stable substrate. Knauf GIFAfloor panels have excellent thermal conductivity making HUGO18 panels ideal over Insulated floating UFH systems for all finishes including ceramics.