Polymer vapor barrier AIRTIGHT WHITE

VOC-free liquidfor wallfor floor

Product summary
Passive Purple Airtight White

• VOC-Free Airtight, Vapour & Gas Control Membrane

Overview
Passive Purple Airtight White is a VOC-free, water-based airtight membrane providing reliable vapour control and protection against radon and methane gases without harmful chemicals or fumes. It can be applied directly onto plasterboard if a vapour control layer has been missed. When used with IM Primer it can be left on show or painted over, making it suitable for exposed environments such as car parks, museums, and stairwells. Once dry, it forms a tough yet flexible polymer membrane that moves with the building and resists impact damage, eliminating the rips, tears, staple holes and failed tapes associated with traditional paper membranes.

Key benefits

• VOC-free, water-based formulation
• Provides vapour control and airtightness
• Also functions as a radon and methane gas barrier
• Can be sprayed (airless) or rolled; suitable to be left exposed or painted
• Tough, flexible polymer membrane with high impact resistance
• Reduces labour and waste; fast coverage by spray application

Tested & Certified — worldwide
Independently tested to both ASTM (ICC-ES) and EN standards; suitable for worldwide specification.

• 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)
• Reaction to fire — Class A to ASTM E84 (Flame Spread 0); 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)
• High solar reflectance — white finish reflects more solar energy (purple grade SRI 52, ASTM E1980)
• Radon barrier — diffusion coefficient 3.3 × 10⁻¹² m²/s (ISO/TS 11665-13)
• Methane / ground-gas barrier — low permeability (ISO 15105)
• Strong adhesion — steel 2.7, CLT 1.83, gypsum 1.6, brick 1.5 N/mm² (EN ISO 4624)
• Flexible & crack-bridging — ~219–350% elongation (EN 12311-1)
• 10/10 mould resistance — no defacement (ASTM D3273)
• Environmental Product Declaration (EN 15804)
• ICC-ES ESR-4715, Passivhaus certified & BBA approved

Uses (spray or roll)
Designed for projects where airtightness must be achieved without compromising appearance. Applied by airless spray or roller, it creates a smooth white finish that can be left on show — ideal for retrofit projects, heritage buildings, basements, car parks, stairwells, and other internal spaces requiring a clean look.

Where it works best

• Internal retrofit airtightness upgrades
• Areas where white finish needs to be left exposed (lofts, basements, services zones, car parks, lift shafts, stair wells, plant rooms)
• Floors, walls and ceilings (vertical and horizontal areas)
• Service penetrations when detailed with the dedicated brush-grade product for detailing

Coverage & application notes
Coverage example: OSB: 13–14 m² per 11.4kg tub (coverage will vary by substrate and application method). Applied by airless spray up to ~300 m² per day per operative; roller application suitable for smaller projects and detailing.

Related technical highlights

• Product Collection: Passive Purple
• Applied By: Spray or Roller
• Colour: White
• Size: 11.4kg
• Certification note: BS Fire Class C | EN 13501-1:2018, cl. 11

Caractéristiques / spécifications techniques

• VOC-free, water-based liquid-applied airtight membrane
• Airtightness: Passive House Class A; measured 0.02 m³/h·m² @ 50 Pa (EN 12114)
• Air barrier: 0.02 L/s·m² at 75 Pa (ASTM E2178)
• Radon diffusion coefficient: 3.3 × 10⁻¹² m²/s (ISO/TS 11665-13)
• Methane / ground-gas: low permeability (ISO 15105)
• Adhesion (EN ISO 4624): steel 2.7 N/mm²; CLT 1.83 N/mm²; gypsum 1.6 N/mm²; brick 1.5 N/mm²
• Elongation / crack-bridging: ~219–350% (EN 12311-1)
• Mould resistance: ASTM D3273 (10/10)
• Reaction to fire: ASTM E84 Class A (Flame Spread 0); Euroclass C-s1,d0 to EN 13501-1 (B-s1,d0 with intumescent additive FRED)
• Watertight to EN 14891; vapour control Sd ~0.8–40 m (EN ISO 12572)
• French A+ / Finnish M1 indoor-air emissions ratings (EN 16516 / RTS)
• Environmental Product Declaration available (EN 15804)
• ICC-ES ESR-4715, Passivhaus certified, BBA approved
• Typical coverage: OSB 13–14 m² per 11.4kg (substrate dependent)