ECOAER / Synwer Sd2/100 Airtight Membrane 1.5m x 50mtr VCL

ECOAER / Synwer Sd2/100 Airtight VCL Membrane 1.5m x 50mtr is a two-layer, translucent airtight vapour control layer with an Sd value of 2m and is 100gramme/m2 in weight. It is manufactured as a combination of an upper protective layer of water-repellent, UV-stabilised, completely 100% airtight, polypropylene spun bound fleece and on the underside, the functional film, slightly diffusible (allowing slow vapour diffusion) polypropylene film. With its optimum fixed Sd value, 0m, this fully 100% airtight VCL is perfectly suitable for the underside of ceilings in most pitched roof applications, where breathable roofing membranes (with typical Sd values of Sd 0.02) are incorporated, as they are diffusion open to the outside.

The decision on which airtight vapour control layer to choose in a warm roof (lived-in attic space) or cold roof detail (with the AVCL fitted, say, for instance, at first floor ceiling level) is often made on the basis of a simple principle or “rule of thumb”, which states that a roof or wall construction should, in relation to water vapour migration, be “tighter on the inside than on the outside”. But just how much tighter should the ACVL be? Another simple “rule of thumb” states that “10 times more diffusion-proof on the inside than on the outside is optimal”.  If the roofing membrane on site is “vapour open” and has an Sd-value of Sd0.2m then the Synergie Sd2.0m is 100 times higher Sd than the Sd-value of the external roofing membrane. This is perfect, as any vapour molecules that can pass slowly through the Sd2.0 membrane will easily be dealt with by the Sd0.02 vapour open properties of the pitched roof sarking membrane, ensuring that no build-up of condensation on the underside of the roofing membrane will occur. Both membranes are vapour permeable and allow for natural open diffusion to occur.

To summarise, the Sd2/100 AVCL is a 100% completely airtight membrane with a “Resistance to Penetration of Air” of less than 0.002m3/(m2h/50Pa) and as outlined above, performs as a Vapour Control Layer with a declared Sd-value, or “water vapour transmission rate” of Sd2.0m, as per the attached Technical Data Sheet (TDS), dated 28^th July 2020, and the Declaration of Performance (DoP), dated 15^th July 2020.

The Sd2/100 Airtight VCL Membrane 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.”