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Duo Flexible Window Membrane

ME500 is a polyethylene copolymer film with non-woven fleece fabric. It is an intelligent membrane providing perimeter window seal for airtight internal & weathertight external joints.


ME500 Duo Flexible Window Membranes (E & W) comprises a tear-proof woven fleece fabric with a polyethylene copolymer film. An integrated movement pleat is included in the foil which complies with the planning and installation recommendations of DIN 4108-7 and with the RAL Quality Assurance Association for windows and doors. It is attached to the wall with butyl adhesive, and to the window /door with a self-adhesive strip. The product has a specially designed reactive foil - water vapour permeability (sd value) changes depending on the humidity inside the joint. This allows the product to perform as an intelligent seal for airtight internal joints, and weathertight breathable external joints. The intelligent reactive system ensures that the joint always dries at the maximum rate. In non-fenestration applications, the membrane can be used to seal across adjacent insulated panels as an airtight or weathertight seal


  • The variable sd value ensures that the joint dries out quickly, thus protecting against mould and moisture damage
  • Single product acts as internal airtight seal and external weathertight but breathable seal
  • Easy fixing to frame and wall

Usage Guidelines

ME500 is an intelligent membrane providing perimeter window seal for airtight internal and weathertight external joints.


ME500 (E and W) is a polyethylene copolymer film with non-woven fleece fabric and acrylic self-adhesive or gasket (ME500-W only) and butyl adhesive strips for location to frame and wall respectively that is used in window installation.


Item Number
Roll Length
Quanty Per Box
E version 80-110 mm
50 m
E version 110 - 140 mm
50 m
E version 140 - 170 mm
50 m
E version 220 - 250 mm
50 m
W version 60 - 80 mm
50 m
W version 80 - 110 mm
50 m
W version 110 - 140 mm 
50 m
W version 220 - 250 mm 
50 m


* E Version - Acrylic/Butyl-Supplied on the same face of the membrane (one down each edge)

W Version - Acrylic/Butyl-Supplied on opposite faces of the membrane (one down each edge)

**Width-110-140 comes with a pleat to accommodate movement. Supplied 110mm and if the pleat is opened 140mm


Technical data

PropertyTest MethodResult
Class of building MaterialDIN 4102(Normal flammibility), P-NDS04-292
Water Vapour PermiabilityDIN 4108-3sd value between 0.3 and 20 mm, depending on average atmospheric humidity, and acts as an intelligent vapour barrier
Water Vapour Resistance Factor (μ)DIN 52615600-40,000
Adhesive Strength of Butyl 12 N/25 mm
Adhesive Strength of Self-Adhesive 12 N/25 mm
Compatibility with Conventional Building MaterialsDIN 52 452passed
UV Resistance - Fleece Face Exposed approximatley 3 months
UV Resistance - Shiny Face Exposed approximately 2 weeks

DIN 18 542 

EN 1027

DIN 18 542 < 0.1 m3/[h m (daPa)n]  
Weathertight Against Driving Rain > 600 Pa
Temperature Resistance – 40°C to +100°C
Application Temperature + 5°C to + 45°C
Storage Period 1 year
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