Passive Purple Retrofit - Retrofit Airtightness Brush Applied Paint (5kg)
Passive Purple Retrofit - Retrofit Airtightness Brush Applied Paint (5kg)
Here at Intelligent Membranes, we have a range specifically for retrofitting air tightness and vapour control. Not only are the products extremely effective, but they are also environmentally friendly. Airtightness and controlling vapour equals better energy efficiency and a healthier environment for the inhabitants.
Passive Purple: The fact that Passive Purple is a liquid membrane means that it adheres to the surface it is applied to making it very difficult to damage. Unlike a paper membrane which can be susceptible to cuts, It impregnates the surface it is adhered to and creates an airtight substrate filling any holes, cracks, penetration leaks or problem areas.
Tested & Certified — worldwide
The Retrofit brush grade is the Passive Purple liquid airtight membrane formulation — independently verified to both ASTM (ICC-ES) and EN standards:
- 🌿 French A+ indoor-air rating & Finnish M1 class — 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 to ASTM E84; Euroclass C-s1,d0 to EN 13501-1 (B-s1,d0 with FRED)
- 💧 Watertight (EN 14891) & intelligent vapour control, Sd ~0.8–40 m (EN ISO 12572)
- 🧱 Strong adhesion — steel 2.7, CLT 1.83, gypsum 1.6, brick 1.5 N/mm² (EN ISO 4624)
- 🦠 10/10 mould resistance (ASTM D3273) · 🛡️ radon & methane barrier · ♻️ EPD (EN 15804)
- ✅ ICC-ES ESR-4715, Passivhaus certified & BBA approved
See all test data & certifications →
Related Guides
Helpful guides related to this product:
- 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
Quality assurance: Download the free Installation & QA Record sign-off sheet (IM-QA-07) for this product.