While traditional damp-proof membranes trap moisture and hold up work while the relative humidity of the concrete falls, Delta-FM is a BBA accredited product from Delta Membrane Systems that allows work to continue immediately after placement.

This is thanks to the low stud profile which allows the membrane to isolate damp and contamination from the slab underneath – even if it is an old installation with no previous dpm, or a new pour which is still "green".

Specifically designed for flooring applications, Delta-FM features a 3mm stud that allows the membrane to control the dampness, and eliminates the risk of contamination leeching from the concrete slab. Once laid, the membrane can be worked on immediately.

A further benefit of the slim profiles is that Delta-FM minimises changes in floor level – particularly important in refurbishment work where maintaining the previous floor level is crucial.

Supplied in rolls measuring 20 metres x 2 metres for speedy application, each roll features a 65mm flat tab on one side to overlap and seal sheets with DELTA-Tape.

Other features include good chemical resistance, the prevention of root penetration, rot resistance, and the ability to operate in extreme temperatures – from -30OC to +80OC. This high upper limit makes it ideally suitable for use with underfloor heating systems.

Various floor finishes can be applied over the sheet including t&g timber floor boards or chipboard sheets (directly onto the membrane or on joists), as well as 50mm screed, Ardex A35 fast-drying screed, poured concrete, laminate floors or stone slabs.

All of these can be upgraded with thermal or sound insulation.

Delta-FM is one of a wide range of membranes from Delta to offer solutions in damp-proofing in refurbishment and new-build projects.