An acoustic damping building material

An acoustic damping building material comprising an acoustic damping layer secured to a substrate 310. The acoustic damping layer comprises at least two media configured such that it has direct and indirect sound transmission pathways through the layer. The layer preferably comprises particulate rubber or plastics material 322 with interstitial fluid (air) filled voids 324. The plastics may be bonded together with a polymeric binder. The substrate preferably has integral tongue and groove edges and may be provided with the acoustic layer on both sides to form a sandwich panel. The substrate may be a fibre cement panel. In a system and method of building the acoustic panel is attached to a building sub-frame. The panel may be used for floors, walls and ceilings and in use absorbs and/or dissipates noises within the damping layer, whilst the substrate reflects sounds back into the damping layer, therefore it reduces noise via impact and acoustic or vibrational transfer through the building structure.