The NHBC has announced Polythene Damp Proof Course made to BS 6515:1984 is not suitable to form cavity tray protection to window and door openings.
The compliant solution is available from Cavity Trays Ltd. Preformed Type C Cavitrays are ready-shaped, self-supporting and cavity width biased to protect the as-found cavity width.
An interesting silent study presentation provides more information and some surprising data, it’s essential viewing.
Access via; www.directcontactexhibitions.com select CPD academy, and select Cavity Trays 3.