Protection liquid waterproofing PASSIVE PURPLE® EXTERNAL BRUSH

air barrierfor facadefor roof

Description
Passive Purple External Brush is a brush‑applied liquid waterproofing membrane formulated to seal joints and gaps on external façades with airtightness and weather protection. The brush variant contains specialised fibres to bridge larger joints and irregular substrates while maintaining vapour permeability.

Tested & Certified — fire‑rated, watertight & breathable

• Reaction to fire: Euroclass B‑s1,d0 (EN 13501‑1 on A1 substrates ≥653 kg/m³) and ASTM E84 Class A (Flame Spread 0 / Smoke 15)
• Watertight: Class W1 (EN 13859‑2) and water permeability Class W3 (EN 1062‑3); near‑zero water absorption (EN 16302)
• Breathable / vapour‑open — Sd ≈ 0.6 m (EN ISO 12572)
• Crack‑bridging: A3 (23°C) / A4 (‑10°C) (EN 1062‑7) and CO₂ / carbonation barrier Class C1 (EN 1062‑6)
• UV‑stable (strength increases after 500 h UV) · low‑emission EMICODE EC2 · anti‑fungus (rating 0)
• Kiwa BDA Agrément (BAW‑21‑214‑P‑A‑UK) · Passive House component (phB) · US ICC‑ES AC212 water‑resistive barrier

Key Features and Benefits

• Brush‑applied sealing: fibre‑reinforced formulation to span larger gaps and irregular surfaces for continuous seals
• External weather protection: designed for façades, roofs and other weather‑exposed assemblies
• Improves airtightness: suitable for energy‑efficient and Passivhaus projects
• Brush‑on access: allows precise application in detailed or difficult areas, suitable for new build and retrofit work
• Breathable waterproofing: maintains vapour permeability while providing water resistance

Uses

• Adhesion to insulation panels
• Concrete and masonry façades
• Fibre cement boards
• Engineered timber / OSB panels

Directions for use

• Remove salts, dust, loose material and standing water from substrates
• Apply on a closed surface; fill holes/joints beforehand with fast‑setting cement repair or polyurethane foam if required
• Apply Passive Purple External at T < 5°C (also substrate temperature)
• Application on damp substrates is permitted if no standing water is present
• Do NOT add water or solvents
• Do NOT apply in direct sunlight
• Do NOT apply during rain
• Clean tools with water after use

Related guides

• Airtight and Vapour Control for High‑Rise Re‑Cladding
• What is Airtightness (and Why It Matters for Net Zero Buildings)
• Damp Walls? Two Breathable Solutions That Actually Work

Technical specifications

• Usage: External
• Application: Brush
• Colour: Purple
• Packaging: 5 kg unit
• Certification: BS Fire Class B; Euroclass B‑s1,d0 (EN 13501‑1) on appropriate substrates; ASTM E84 Class A
• Watertight: EN 13859‑2 Class W1; water permeability EN 1062‑3 Class W3; near‑zero water absorption (EN 16302)
• Breathability: Sd ≈ 0.6 m (EN ISO 12572)
• Crack‑bridging: EN 1062‑7 A3 (23°C) / A4 (‑10°C)
• CO₂ / carbonation barrier: EN 1062‑6 Class C1
• UV stability: Strength increases after 500 h UV exposure
• Low‑emission: EMICODE EC2
• Anti‑fungal: rating 0
• Approvals: Kiwa BDA Agrément (BAW‑21‑214‑P‑A‑UK); Passive House component (phB); US ICC‑ES AC212