ECOAER / Synwer Sd Variable Airtight VCL Membrane 1.5m x 50m

Synergie Sd Variable Sd 0.2m – Sd (20m) Airtight Vapour Control Layer (AVCL) is a two-layer, moisture-variable performance, fully 100% airtight, vapour control layer.

Variable Sd AVCLs can change their vapour permeable characteristics based on the vapour pressure gradient, or Relative Humidity (RH) surrounding/in close proximity to the membrane.

The two-layer Sd Variable membrane has an upper functional foil film in PA (polyamid). This film is a special kind of plastic that reacts to the humidity in the air and the temperature differentials between outside and insider. The PA film remains completely airtight, while the micropores of the film can increase (open) or decrease (close) their size to allow the passage of water vapour molecules, which are many, many times smaller than air molecules. Vapour can pass through, but air cannot pass.

The lower support layer is PET (polyester spunbond). In the summertime, there is relatively higher RH, and the functional PA foil is “open” vapour permeable, operating at the lower spectrum of Sd0.2, and is very breathable, while in the winter, there is lower RH and the functional PA foil becomes more vapour “tight”, as it operates closer to the upper limit of Sd20.

In the long run, over a few years, this ability to act as a barrier in winter and a breathable membrane in summer, helps to protect the building from structural damage caused by excessive moisture trapped in the building fabric.

The Synergie Sd Variable membrane is ideally suited to flat roof make-ups which are not adequately ventilated or diffusion “vapour tight” towards the outside. The Synergie Sd Variable membrane is also suitable in new build where excessive moisture accumulation has occurred during the initial construction phase of the building process, such as Timber-frame, where timber elements and/or thermal insulation has suffered an unplanned wetting.

The Synergie Sd Variable is fully EU CPR compliant, are CE Marked and are airtight vapour control layer construction products, “fit for their intended use”, and “manufactured in strict accordance with the applicable EU harmonised technical specification DIN EN 13984: 2013-05 Plastic and rubber vapour control layers – Definitions and characteristics.”