Breasa ( I & II ) Housewrap is perfect for breathable membrane for timber frame wall systems and steel frame and concrete wall construction. It is surface-applied and should be fixed directly to the sheathing ply/OSB, insulation or blockwork. The durable, lightweight breathable membrane is windtight and water resistant and designed for use in new build, refurbishment or extension projects and helps improve energy efficiency by retaining heat and reducing drafts.