Finishing paint RETROFIT AIRTIGHTNESS BRUSH

liquidfor woodfor bricks

Overview
The Retrofit Airtightness Brush Applied Paint from Intelligent Membranes is a brush-applied liquid membrane formulated for external retrofit airtightness and vapour control. The product adheres to substrates, impregnates and fills holes, cracks and penetrations to create a continuous airtight layer that is more damage-tolerant than sheet membranes.

Key benefits

• Liquid-applied membrane specifically for retrofit airtightness and vapour control
• Very low VOC emissions — environmentally friendly formulation
• Adheres to multiple substrates to form an airtight substrate that seals holes and cracks
• Brush-applied formulation for targeted external repairs and upgrades

Tested & Certified — worldwide

• French A+ indoor-air rating & Finnish M1 — very low VOC emissions (EN 16516 / RTS)
• Passive House Institute Class A airtight — 0.02 m³/h·m² @ 50 Pa (EN 12114)
• Air barrier material — 0.02 L/s·m² at 75 Pa (ASTM E2178 · ICC-ES ESR-4715)
• Reaction to fire — Class A (ASTM E84); Euroclass C-s1,d0 (EN 13501-1) (B-s1,d0 with FRED)
• Watertight to EN 14891 & intelligent vapour control, Sd ≈ 0.8–40 m (EN ISO 12572)
• Strong adhesion (EN ISO 4624): steel 2.7 N/mm²; CLT 1.83 N/mm²; gypsum 1.6 N/mm²; brick 1.5 N/mm²
• Mould resistance 10/10 (ASTM D3273) · radon & methane barrier · EPD (EN 15804)
• Certifications: ICC-ES ESR-4715, Passivhaus certified, BBA approved

Related guides

• How to Retrofit Vapour Control Without the Mess
• My Builder Forgot the Vapour Control Layer? Here’s How to Fix It
• EnerPHit Explained – The Passivhaus Standard for Old Buildings

Technical specifications

• Product collection: Passive Purple
• Commercial name / series: Passive Purple® Retrofit Brush
• Colour: Purple
• Usage: External (retrofit)
• Application: Brush-applied
• Pack size: 5 kg
• Passive House Institute airtightness: 0.02 m³/h·m² @ 50 Pa (EN 12114)
• Air barrier performance: 0.02 L/s·m² @ 75 Pa (ASTM E2178 · ICC-ES ESR-4715)
• Reaction to fire: Class A (ASTM E84); Euroclass C-s1,d0 (EN 13501-1)
• Watertight to EN 14891; vapour control Sd approx. 0.8–40 m (EN ISO 12572)
• Adhesion (EN ISO 4624): steel 2.7 N/mm²; CLT 1.83 N/mm²; gypsum 1.6 N/mm²; brick 1.5 N/mm²
• Mould resistance: 10/10 (ASTM D3273)
• EPD certified (EN 15804)
• Certifications & approvals: ICC-ES ESR-4715; Passivhaus certified; BBA approved