Shop our range at Selhurst Timber of damp proof membranes designed to prevent moisture from passing through floors and foundations in construction projects. Damp proof membranes are installed beneath concrete slabs and flooring systems to create a protective barrier against ground moisture. Used by builders and contractors across residential and commercial construction, DPM materials help protect buildings from damp issues and improve the durability of floor structures. Are you spending over £150? You will receive free local delivery on qualifying orders across our delivery area.