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wedi Vapor 85 Building Board

£66.34£104.82 (inc VAT)

Please note: There is a 5-7 day lead time on this product.



wedi Vapor 85 Building Board is a special building board with with a pre-integrated vapour membrane barrier applied in the factory.

wedi Vapor 85 Building Board is available in two thicknesses: 12.5mm and 20mm, and two board sizes: 2500 x 600mm and 2500 x 900mm.

wedi Vapor 85 Building Board is the same construction as wedi Tile Backer Board – which consists of a blue core made from extruded polystyrene rigid foam, that is then reinforced with glass fibre (with alkali-resistant finish) on both sides and coated with a polymer-modified cement. This is then coated on one side with a vapour barrier membrane. This membrane has an SD value of 92m and is perfect for challenging applications in areas with very high levels of humidity.

This construction means wedi Vapor 85 Building Board is both a panel type sealing system and a building board with constructional and vapour resistant properties, which is specifically tested and approved for wall applications. It can be used on solid walls and stud frames, as well as on floors and on ceilings, in interior areas. Due to its special properties, it is versatile in its possible applications:

• Carrier element for laying tile, slab and natural stone floor coverings using the thin-bed method, and surface for plaster and other materials
• Vapour barrier
• Effective thermal insulation
• Compound seal with tile and slab coverings on wall surfaces

For reliable sealing of connections, butt joints and intersections between wedi Vapor 85 Building Boards, the high-quality single-component wedi 620 sealant is recommended alongside wedi Sealing Tape, corners and gaiters.

For detailed application instructions for wedi Vapor 85 Building Board, please view the Installation Guidelines datasheet linked below.

Technical Data:
Thickness: 12.5 mm; 20 mm
Vapour barrier (polyethylene foil with special fleece layer): 0.51 mm
Water vapour diffusion equivalent air layer thickness Sd value: 92 m
Resistance to water vapour diffusion (μ) DIN EN 1931 (sheet material vapour barrier): 170,000
Water vapour diffusion flow resistance Z value (sheet material vapour barrier): 555.64 GPa • m² • s/kg 1.54 • 109 m² • s/kg
Water vapour diffusion flow resistance (sheet material vapour barrier): 4,065,287 s/m
Fire behaviour EN 13501, building material class: E
Adhesive tensile strength: 0.27 N/mm²
Linear coefficient of thermal expansion: 0.02 mm/mK

Product Datasheet Installation Guidelines

Click here to view this product on the Manufacturers website.

Additional information

Weight N/A

2500 x 600 x 12.5mm, 2500 x 600 x 20mm, 2500 x 900 x 12.5mm, 2500 x 900 x 20mm


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