Diall 6mm Fibreboard Laminate Floor & Glueless Wood Floor Underlay 9.6 m². This fibreboard underlay is for use with glueless wood & laminate flooring & can be used over all types of sub-floors. It helps to compensates for uneveness in the sub-floor & smoothes surface irregularities whilst reducing sound transmission by 18db. It also provides thermal insulation.