Passive Purple brush applied airtight paint that has fibres in to span and large gaps to make any form of construction airtight

Passive Purple Brush - Airtight Paint

6.9kg
$103.95
$103.95 $165.00
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Passive Purple brush applied airtight paint that has fibres in to span and large gaps to make any form of construction airtight
  • Passive Purple brush applied airtight paint that has fibres in to span and large gaps to make any form of construction airtight
  • Airtight paint for masonry builds that is brush applied
  • liquid airtight paint that is brush applied to seal wall penetrations like water pipes
  • Retrofit airtight paint – Passive Purple applied for improved energy efficiency and airtightness in existing buildings
  • service pipe airtight paint that is brush applied to make an airtight seal
  • airtight paint for joist ends on timber frame or masonry builds
  • airtight paint for joints on OSB timber frame
  • paint brush applied Airtight liquid vapour control
  • Passive Purple brush applied airtight paint that has fibres in to span and large gaps to make any form of construction airtight
  • Airtight paint for masonry builds that is brush applied
  • liquid airtight paint that is brush applied to seal wall penetrations like water pipes
  • Retrofit airtight paint – Passive Purple applied for improved energy efficiency and airtightness in existing buildings
  • service pipe airtight paint that is brush applied to make an airtight seal
  • airtight paint for joist ends on timber frame or masonry builds
  • airtight paint for joints on OSB timber frame
  • paint brush applied Airtight liquid vapour control
Passive Purple Brush - Airtight Paint

Passive Purple Brush - Airtight Paint

$103.95
$103.95 $165.00
Size6.9kg

What is Passive Purple Brush?

Passive Purple Brush is a fibre-reinforced, liquid-applied airtight membrane designed for detailed airtightness work. Applied with a simple paintbrush, it creates a permanent, seamless vapour-control layer that seals tricky gaps and penetrations where spraying or rolling is difficult.

Where is it used?

Passive Purple Brush is ideal for:

  • Service penetrations (pipes, cables, ducts)
  • Window and door frames
  • Floor-to-wall and wall-to-ceiling junctions
  • Cracks and gaps up to 5mm
  • Touch-ups after air testing or snagging

Why use the Brush version?

Unlike spray-applied Passive Purple, the Brush version contains fibres that span and seal larger cracks and irregularities. This makes it the go-to airtight paint for precision work, detailing, and repairs, while still delivering the same Passivhaus-certified airtightness as the main system.

Surface preparation

  • Ensure surfaces are solid, dust-free, and closed.
  • Large gaps (>5mm): Fill with cement-based filler or foam before application.
  • Small to medium gaps (2–5mm): Passive Purple Brush can be applied directly.

Application & coverage

  • Applied with a flat paintbrush.
  • Easy to use for small projects and detailed work.
  • Once cured, it can be painted, plastered, or rendered over.

Why airtightness matters

Air leakage through cracks and junctions:

  • Reduces energy efficiency
  • Allows draughts, damp, and mould
  • Can compromise Passivhaus and building regulations compliance

By sealing with Passive Purple Brush, you ensure every junction is airtight, securing energy performance and long-term building health.

Tested & Certified

Passive Purple Brush is covered by the same independent testing and ICC-ES evaluation (ESR-4715) as the Passive Purple system:

  • 🌿 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 — air leakage 0.02 L/s·m² at 75 Pa (ASTM E2178)
  • 🔥 Reaction to fire — Class A to ASTM E84 (Flame Spread 0, Smoke 35); Euroclass C-s1,d0 to EN 13501-1 (B-s1,d0 with FRED)
  • 💧 Watertight (EN 14891) & intelligent vapour control (EN ISO 12572)
  • 🧱 Strong adhesion across substrates (EN ISO 4624) & 10/10 mould resistance (ASTM D3273)
  • ✅ ICC-ES ESR-4715, Passivhaus certified & BBA approved

See the full test data & certifications, or read how Passive Purple delivers solar-reflective performance (SRI 52).

🇺🇸 US projects: tested to ASTM standards for world markets — download the US specifications (CSI MasterFormat) or order through WickRight, our Chicago distribution & installation partner.

Related Guides

Helpful guides related to this product:

  • What Does Passive Purple Stick To? Adhesion Testing
  • My Builder Forgot the Vapour Control Layer? Here’s How to Fix It
  • What Is a Vapour Control Layer? | VCL Explained
  • The Airtightness Challenge: Why Blockwork Alone Is No Longer Enough
  • Grand Designs Passivhaus Premium Uses Airtight Membrane

Quality assurance: Download the free Installation & QA Record sign-off sheet (IM-QA-02) for this product.

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