Finishing paint AIRTIGHT BRUSH

liquidfor wallwhite

Product overview
Airtight White Brush is a fibre‑reinforced, water‑based polymer emulsion applied by brush to form a permanent liquid vapour‑control and airtight membrane with a smooth white finish. Designed for retrofit and new‑build detailing where the airtight layer may remain visible.

Key features & benefits

• BBA certified & Passivhaus certified — validated airtightness and durability.
• M1 class / very low VOC — water‑based formulation safe for installers and occupied buildings.
• Fire performance — rated to recognised standards (ASTM / EN classifications applicable per formulation).
• Exceptional airtightness — demonstrated 0.03 ACH; Passivhaus metrics 0.02 m³/h·m² @ 50 Pa.
• Universal adhesion — bonds to concrete, brick, timber, plasterboard, OSB, steel, PVC and aluminium.
• Coverage efficiency — ~1 kg ≈ 1 m²; high application rates for brush work (one operative up to ~300 m²/day depending on detail).

Where to use

• Floor, wall and ceiling junctions and perimeters.
• Window and door reveals and visible perimeters.
• Service penetrations: pipes, ducts and cables.
• Small retrofit airtightness projects and detailed repairs.
• Any area requiring a white, exposed airtight coating.

Tested & certified — key performance highlights

• French A+ indoor air rating & Finnish M1 class (EN 16516 / RTS).
• Passive House airtightness metric: 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) in specified formulations.
• Watertight to EN 14891 & intelligent vapour control Sd ≈ 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 ASTM D3273: 10/10. Radon & methane barrier properties; EPD available (EN 15804).

Application guidance

• Apply by brush to prepared substrates; suitable on slightly damp surfaces and for details where tapes fail.
• For large voids/penetrations: backfill with PU foam or backing material, trim excess, then apply membrane generously to create a seamless seal.
• Follow TDS for recommended wet film thickness, drying times and number of coats to achieve required vapour resistance and airtightness.

Documentation & support

• Technical Data Sheet (TDS)
• Installation guide
• Safety Data Sheet (SDS)
• Certificates and test reports (BBA, Passivhaus, ICC‑ES ESR‑4715, EPD)

Technical specifications

• Product range: Passive Purple
• Commercial name: Airtight White Brush
• Application: Brush (brush‑applied)
• Colour: White
• Pack size: 6.9 kg (Home Pack)
• Coverage: approx. 1 kg ≈ 1 m² (depends on substrate & detail)
• Typical productivity: up to ~300 m²/operative/day (brush‑applied; depends on detail)
• Measured airtightness: 0.03 ACH (demonstrated)
• Air barrier test: 0.02 L/s·m² at 75 Pa (ASTM E2178 · ICC‑ES ESR‑4715)
• Passive House metric: 0.02 m³/h·m² @ 50 Pa (EN 12114)
• Reaction to fire: Class A (ASTM E84); Euroclass C‑s1,d0 (EN 13501‑1)
• Watertight: EN 14891
• Vapour resistance (intelligent): Sd ≈ 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
• Emissions: French A+ / Finnish M1 — very low VOC
• Mould resistance: ASTM D3273 = 10/10
• Certifications: ICC‑ES ESR‑4715, Passivhaus certified, BBA approved, EPD (EN 15804)