<b><b>Following proposed changes to sound insulation rules (Part E), Andrew Leech finds out how manufacturers are responding to the intense competition in the drywall market. And once the walls are up, what do we do for decoration? </b></b><br><b>The well-aired changes to Building Regs Part E that are scheduled to take effect next year call for increasing the internal sound insulation of separating walls by at least 3dB, and separating floors by a minimum of 4dB. They are also intended to reduce external noise transmission caused by road traffic and aircraft and, of course, over-exuberant neighbours. </b><br><b><b>Drywall implication </b></b><br> Part E's machinations have most significant implications for traditional brick and block homes and for wet trades and drywall installations. Whilst for the latest steel and timber frame construction techniques there should be little or no change to the specifications commonly used. <p></p><p>The regulations demand a minimum board mass of 9kg/sq m, thus eliminating single 9.5mm thick plasterboards from partitioning, and even some standard 12.5mm boards. But it remains practicable to use thinner boards provided they are greater than 9kg/sq m in mass and fixed as double layers, or as a single layer with an insulation quilt in floor and wall cavities. …