Passive Purple External Brush: Airtight & Waterproof breathable paint - Brush Applied Airtight Facade Membrane

Product Application – Passive Purple External Brush

The Passive Purple External Brush is a brush-applied airtight membrane designed for sealing detailed junctions, penetrations, and small areas where spray application is not practical. Once cured, it forms a durable, seamless airtight barrier suitable for a wide range of construction substrates.

Suitable Substrates

• Concrete and cementitious surfaces
• Masonry and blockwork
• Timber and engineered wood
• Plasterboard and gypsum
• Steel decks and curtain wall interfaces
• Existing coated or painted substrates (sound, stable surfaces only)

Directions for Use

1. Preparation
   • Remove dust, dirt, grease, efflorescence, loose material, and standing water.
   • Ensure all substrates are clean, sound, and dry-to-damp (not wet).
   • Fill large gaps or holes with a fast-setting cement-based filler or polyurethane foam if required.
2. Application Conditions
   • Apply only when the substrate and ambient temperature is above 5°C.
   • Application on slightly damp substrates is permitted, but standing water must be removed.
3. Application Method
   • Apply directly with a brush, working well into corners, penetrations, and junctions.
   • Use one or two coats, depending on the detail and surface porosity.
   • Allow the first coat to dry completely before applying the second.
4. Aftercare
   • Clean all tools immediately with water after use.
   • Once cured, the membrane provides long-term airtightness and detailing protection.

Key Application Benefits

• Precise detailing on challenging junctions and penetrations
• Excellent adhesion to multiple substrates
• Flexible, seamless airtight finish
• Compatible with spray-applied Passive Purple External spray for full system continuity