Protection against groundwater ingress as well as gases and chemicals is offered by DualProof – a new two-layer durable watertight solution for below ground structures from Delta Membrane Systems.

This is a fully and permanently bonded, pre-applied membrane which is fitted prior to the fixing of steel reinforcement, and the concrete pour. It comprises a sealed two-layer flexible pvc membrane laminated with a non-woven polypropylene fleece.

This fleece makes use of FiberTex technology which gives the necessary bond to the concrete, as it integrates into the concrete when poured giving a strong mechanical bond once cured. It then prevents any lateral water migration between the membrane and the structural concrete, and it even seals small cracks in the concrete.

No heat or exposed flames are needed in the installation process – the membrane is simply overlapped and sealed with butyl tape and special adhesive for detailing. As it can be applied in horizontal and vertical planes, there are many suitable applications for DualProof including new-build basements, foundations, tunnels and any other concrete construction below ground. It offers high compound shear strength, and it can be installed at any time of year, no matter what the weather conditions and temperature. It is also suitable for salt water applications.

Measuring 1.7mm thick, DualProof comes in a 1.2m wide by 25m long rolls.