DECKfon acoustic overlay treatments are created for conversion projects where the joist is covered with a timber decking and the ceiling is to be replaced. In addition, they can be used to reduce impact sound transmission though concrete floor. DECKfon soundproofing overlay boards come in three thickness’ 17mm (17T), 26mm (26T) and 30mm (30T). The boards have been created to increase the sound proofing performance of existing timber floors in a refurbishment development. Each board is installed on top of a timber sub-deck, laid on timber joists. DECKfon acoustic board has a tongue and groove edging with a facing thickness of 9mm moisture resistant MDF.