Sika Membran 540

Self-adhesive air / vapor barrier

SikaMembran®-540 is a self-adhering sheet membrane consisting of an engineered block-copolymer adhesive on a durable, conformable polypropylene film. The membrane is designed to be adhered to a variety of substrates and is available in rolls of various widths which may be used for full wall applications or as a penetration/flashing membrane used with other Sika air barrier systems.

Where to use

SikaMembran®-540 is designed to be used in above grade wall assemblies including concrete, concrete masonry units (CMU), plywood, OSB and exterior gypsum sheathing. Other applications include transition tape application for door, window and other openings and to connect the air barrier to the door, window or other penetration.


  • Fully bonded
  • Waterproof and airtight
  • Excellent adhesion to a variety of substrates
  • Compatible with Sikagard liquid air barriers
  • Tough film that resists punctures and tears
  • Conforms to irregular surfaces
  • Passes E 2178



Horizontal applications should start at the bottom and proceed upward, offset vertical seams 12”. Vertical applications should start at the top and unroll the membrane down the wall, offset horizontal seams 12”. Lap at all seams should be 2”. Sequence the installation, including detailing at wall openings such as windows and doors, to provide a continuous install with shingled laps.

Cut membrane to a manageable length and position for alignment. Remove protective film and press firmly into place avoiding wrinkles and air pockets. Go over recently installed sheet with a hand roller in order to ensure continuous and intimate contact with the substrate.

For masonry ties and anchors use the 18” wide sheet. Run the upper edge of the membrane along the underside of the tie or anchor. Working up the wall, install the next sheet in a similar manner. The 18” membrane will overlap the membrane below by 2” and will require as lot or cut at each tie or anchor at the bottom of the sheet in order to be fully laid in place. Seal the penetration using Sikaflex® 11fc.

Seal leading edges susceptible to moisture ingress such as non water leading edges and edges resulting from partially completed walls at the end of a day, with Sikaflex® 11fc.

Coordinate installation with the roofing trade to ensure continuity between the roof and air barrier systems.

Protect membrane from damage and do not cover until inspected according to the project requirements. Make repairs to the membrane using SikaMembran®-540. Extend beyond the damage by at least 3”. Seal the edges of the patch with Sikaflex® 11fc.

Adhesion tests should be carried out before the project install commences and should be checked periodically a tleast once per day on each substrate type throughout the project installation to verify proper adhesion and application.