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Board Composition

A 9.5mm thick mechanically-bonded composite panel fire protection system

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Home Durasteel Board Composition

Board Composition

Durasteel Exploded Diagram

Durasteel is a mechanically-bonded 9.5mm thick composite panel of fibre-reinforced cement core (A) and punched steel sheets on both sides (B). The steel sheets are pre-punched and pressed into the core during the manufacturing process, creating a unique, durable and high strength composite panel that provides high-performance fire, blast, impact and moisture resistance properties. Durasteel is classed as ‘noncombustible’ to BS 476: Part 4: 1970 and to Clause 10 of EN 13501-1: 2002.

Durasteel is available in both galvanised and stainless steel finishes.


Weight 22.0 kg/m²


Flexural Strength (425mm span) 65 N/mm²
Apparent Modules of Elasticity (425mm span) 30.9 kN/mm²
Impact Strength (BS 5669: Part 1) 44.15 J
Impact (Withstand) 4000 J
Impact Resistant (Projectile) 2793 J


Natural Moisture Content by Weight 7-8%


Thermal Conductivity at 20 degrees Celsius (BS 874) 0.55 W/Mk
Radiant Heat Reduction through Panels 9.30 to 2.53 Km/m²


Sound Reduction Index 7-8%


Non-Combustible to BS 476 parts 4 & 11 Non-Combustible
Building Regulation Classification Class 0


Material class Non-Combustible
Surface spread of flame Class 1
Building Regulations classification Class 0
Alkalinity (approximately) pH (core) 10-13
Thermal conductance (approximately) at 20°C W/m²K
Coefficient of expansion (20-100°C) m/mK 15 x 10-6
Nominal moisture content (air-dried) % 6
Moisture movement (ambient to saturated) %
Thickness tolerance of standard boards +1.0 to -1.0
Length x Width tolerance of standard boards mm ±2.0

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SpecUp - System Specification Wizard

Answer the 5 short questions below to receive your recommended Durasteel system specifications. Hover over the ? icons for a brief explanation.

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Question 3/5

Fire integrity-only or integrity and insulation?

Question 4/5

Fire attack risk from one side or both sides of the system?

Question 5/5

Blast rating required in addition to fire rating?

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