Product Description:

Our DPC Polythene is a flexible damp proof course supplied in a 300mm x 30m roll, used to form a moisture barrier within masonry. The 300mm width suits walls and piers up to around 290mm thick, and gives enough material for detailing work where a narrower DPC would fall short, including cavity trays, stepped DPCs, beneath window sills and door thresholds, around openings, and under copings on wider walls.

Wider DPC is most useful where moisture has to be directed as well as blocked. Over openings and at abutments, a DPC is often shaped into a cavity tray, stepped up across the cavity from the outer leaf to the inner, so that any water entering the cavity is carried back out through the external wall rather than onto lintels, frames, or the inner leaf. Beneath sills and thresholds, the extra width allows the DPC to be turned up behind the frame and dressed across the full depth of the wall. The 300mm roll gives the material to do that in one continuous piece without joints.

Polythene DPC is lightweight, easy to cut with a knife, and quick to lay on a fresh mortar bed, and it can be cut down along its length for narrower walls when a job requires several widths. Joints and corners should be lapped by at least 100mm, and on buildings the DPC must link with the floor damp proof membrane so the protection is continuous. Keep it clear of render, pointing, and raised ground levels outside, which would let moisture bridge around it.

Specification: