What is CHAR 21 (Plaster)
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 plasterboard partition walls. On 12.5mm plasterboard this product achieves EI 60. Test data available on request. 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.
Application
Suggested equipment is an airless spray piston pump with a minimum compression rate of 40:1, minimum pressure 150 bar (e.g. GRACO MARK V or WAGNER ProSpray PS34), Reverse-A-Clean self-cleaning tips, nozzle diameter 19/21/23 mils, flexible feeding pipe 3/8″ of maximum length 30m. Average volumetric flow rate in common airless spray applications ranges from 3 to 6 L/min. Gun, line, and feed filters should be removed.
To achieve EI 60, 1 kg/m3 is required, or 770 ml/m2. This can be applied in a single coat by airless spray, or approximately 3 coats when applied by hand. Product may be thinned with 5% water, if necessary, though not generally required. Mechanical/paddle mix prior to application for smooth and consistent flow. Application can also be done by brush or roller with 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
CHAR 21 has been tested for adhesion on bare plasterboard and emulsion painted surfaces. Tests show good adhesion
in all instances. Loose, peeling, or cracked paint shall be removed before application. Glossy or varnished surfaces should be keyed to provide a suitable surface for adhesion. 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 distributor. An approved topcoat is required for environments C2 and above.
Certification
CHAR 21 comes with European certification and numerous type approvals in Europe and other countries. Performance for fire protection of reinforced concrete and pre-stressed reinforced concrete structures, test and assessment reports are available according to EN 13381-3 both for beams/columns and for slabs/walls up to R 120. Application for compartment walls is supported by classification according to EN 13501-2 (fire tests according to EN 1364-1) for: Masonry bricks with rendering (EI 120) Concrete blocks without rendering (up to EI 180), and Drywall (EI 60)
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