Fire Rating (Reaction to Fire): A2(Limited combustibility)
Fire rating: A2
4.5mm Cembrit Windstopper Extreme is a high-performance, breathable sheathing board designed for demanding exterior wall applications. Engineered to withstand harsh weather conditions, it combines exceptional wind resistance with vapour permeability, making it ideal for use behind ventilated façades and in energy-efficient wall assemblies.
Note: formerly known as Cembrit Windstopper Extreme
CHARACTERISTICS
Cement-bonded fibre board with enhanced density and durability
Provides superior protection against wind-driven rain and air infiltration
Allows vapour to escape from the building interior while preventing external moisture ingress
Non-combustible; suitable for fire-rated constructions
Highly resistant to rot, mould, and fungal growth
Designed for extreme climates and prolonged exposure
Natural rough texture due to non-compressed manufacturing process
Can be left exposed for up to 6 months when installed according to Swisspearl guidelines
APPLICATION
Compatible with timber, steel, or aluminium substructures
Insulation may be placed directly against the inner face of the board
No surface treatment required during temporary exposure
Supports airtight and energy-efficient building envelopes
BBA-Certification-Windstopper-Extreme.pdf