QA Finefloor Fibreboard Underlay 10.03m2. FibreBoard provides a level subfloor for the final floor covering by smoothing out unevenness in the subfloor. FibreBoard is easy to line up, cut and fit – saving time and effort on installation. FibreBoard is made from 100% natural wood fibre, making it very eco-friendly. Lightweight panels to eliminate uneven subfloors and improve insulation. Natural wood fibre insulating panels for laminate, engineered, and solid wood domestic installations.