What is CHAR 21 (timber)
CHAR 21 is a very low VOC, waterborne, high performance intumescent coating providing a very effective fire barrier thanks to high active solids content, char strength and the use of nanofillers. Rapid development of a stable, insulating char provides effective and long-term protection to flammable and non-flammable substrates.
CHAR 21 can be used for fire protection of timber-based substrates. It achieves a Euroclass B-s1-d0 rating.
CHAR 21 has superior environmental accreditation, assessed by EN 16000 tests for indoor emissions, ISO 89011-2 tests for VOC content and carries approval from LEED, BREEAM, CAM, French VOC and more.
CHAR 21 achieves Euroclass B-s1-d0 on wood-based substrates of 10mm or more.
Application
Can be applied by brush, roller or spray.
For timber, rating is achieved with one coat of 250g, or 200ml, per m2. This may vary with different equipment, always check WFT with a gauge as you apply. Actual application thickness should be in accordance with your report and Spec.
Contact distributor for a specification.
Product may be thinned with 5% water, if necessary, though not generally required. Mechanical/paddle mix prior to application for smooth and consistent flow.
For application by brush or roller use long single strokes, avoiding overworking the paint. Application by brush/roller requires more coats than airless spray. Proper environmental conditions must be kept during application and drying.
Primers/Topcoats
Bare timber does not require a primer.
Painted or coated surfaces should be treated with Wall Primer 3500 to ensure proper adhesion. WP 3500 is thinned with 2L of water per 1L of primer to achieve an ultrafine solution with an application rate of 10m2 per L. Pre-thinning rate of 30m2 per L. No film should appear on the surface after drying.
CHAR 21 does not require a topcoat for C1, internal warm dry environments, though can be top coated for decorative purposes with product approval from our Sales & Technical department. An approved topcoat is required for environments C2 and above.
Certification
CHAR 21 is achieves a reaction to fire rating; Euroclass B-s1-d0.
Available certificates and test reports are in accordance with European fire standards. Reaction to fire test according to EN 13501-1. Classification tests are performed according to EN 13823:2020+A1:2022 and EN 13823 on wood particleboard detailed according to table 1 (312).
Test report
Therefore, according to EN 13823 paragraph 5.3 results apply to all types of wood and wood-based substrates and also on all flammable substrates rated A2 or better. This performance is achieved with 250 g/m2 active layer.
Properties of Char 21
DENSITY: 1.3 ± 0.05 kg/dm³ at 20°C
SOLIDS CONTENT:
78% ±5% w/w
67% ±5% v/v
COLOUR: White
STANDARD PACKING: 20kg plastic drums
SHELF LIFE: 12 months in original packing and proper environment
SPREADING RATE: 0.55 ± 0.05mm dry film thickness with 1kg/m² wet (theoretical)
APPLICATION: Normally by airless spray. For small surfaces or retouching, by roller or brush.
WET THICKNESS PER COAT:
Airless spray: max 1000 µm (750 µm DFT)
Brush or roller: max 500 µm (300 µm DFT)
THINNING: Not recommended (if necessary, with water max 5%)
DRYING TIME (*):
8 hours – touch
24 hours – complete
(*) @ +20°C and 60% RH.
Drying time depends on DFT, temperature, and relative humidity.
MIN APPLICATION TEMPERATURE: +5°C
MAX APPLICATION TEMPERATURE: +45°C