Knauf Vapour Panel Square Edge 2400 x 1200 x 12.5mmOur Vapour Panel has a metallised polyester foil laminated on the reverse of plasterboard. The Vapour Panel is designed to be used where warm and cold elements of walls and ceilings join and water vapour control and a plasterboard lining are required in one fixing application. Applications include the internal face of an external wall and roof scenarios, and in particular loft conversions.