Non-compliance with the RRO can result in prosecution, either in fines or imprisonment.
Building Regulations and the associated documents require elements of a building to provide minimum periods of fire resistance, expressed in minutes. This is not the property of an individual material but a measure of the overall performance of a complete system when exposed to standard heating conditions.
Fire resistance in local UK standards is defined in BS 476: Part 20 1987 and new European legislation will eventually replace national standard as EN1366.
• Load bearing capacity (R)
▸ The ability for a building element to resist a fire when supporting an external load without losing its stability. For floors, flat roofs and beams, allowable
vertical deflection is limited to 1/20th of the clear span.
• Integrity (E)
▸ Ability for a building element to prevent the passage of flames and hot gases; resisting collapse, the occurrence of holes, gaps or breaks.
• Insulation (I)
▸ Ability for a separating element to restrict the temperature rise on the unexposed side.
Reaction to Fire
The material choice for walls and ceilings can significantly affect the spread of flame and its rate of growth. The specification of linings is particularly important in circulation spaces where rapid spread of flame is most likely to prevent occupants escaping.
The reaction-to-fire classification covers the potential for flashover, the spontaneous ignition of hot smoke, gases, and fuel that can cause a fire to spread uncontrollably.
Two other hazards encountered in fires, and therefore subject to risk assessment, are classified by s (for smoke production) and d (for flaming droplets). They relate to the quantity of smoke produced (s1 is the least; s3 is the most) and the potential for flaming droplets to fall (d0 means no droplets, d3 many droplets).
Surface spread of flame
• Class 0 compliance
▸ British Standards refer to Class 0 compliance. Class 0 is the spread of fire across the
surface of a building material – what’s known as the surface spread of flame – and the non-combustibility of that surface.
• Euroclass harmonisation
▸ The Euroclass classification of building products harmonises standards of fire safety across Europe, including England, Scotland, and
Wales. The intention is that it will replace the British Standards. The classes A1, A2, B, C, D, E, and F rank a product’s reaction to fire. The
safest products are A1, the most dangerous are E. F is not classified.