A Changed World: The Choices Facing Specifiers of Fire Safety Systems

The principles of building performance in the event of a fire have remained constant for years, with the overarching goal to reduce the risk to people and property if there is a fire. Buildings are designed to allow for safe evacuation, by ensuring there is no premature failure of any element within the building itself, and fire and smoke cannot spread from one compartment to another.

UK construction professionals need to consider how to control or restrict the spread of a fire and maintain the fire resistance of the building. Such fire protection measures can be classified as either active or passive, although good building design will use a mix of technologies.

Active measures include systems which respond to the presence of a fire, including fire detection and alarms, smoke control measures or suppression systems.

Passive measures, also sometimes defined as “built in” fire protection, include materials and systems that make up, or sit in, the fabric of a building to restrict and prevent the spread of fire, and protect the overall building structure. Many building materials, for example bricks and concrete, have a measure of natural resistance to fire. However, natural fire resistance may be enhanced using additional materials to improve or maintain a buildings performance. Unlike active systems, passive fire protection does not require any special energisation or command signal to operate and can be broken down into four main areas.

1. Fire protection to the structural frame of the building
2. Internal compartmentation
3. Building services
4. The building envelope

The choice of fire safety materials and systems, including passive fire protection measures have come under greater scrutiny in recent years, driven by the “Independent Review of Building Regulations and Fire Safety”, conducted by Dame Judith Hackitt. There has been a push for improved guidance and regulations for building professionals, requiring:

• Improved overall clarity in existing regulations and guidance
• More accountability for the safety of a building throughout its lifecycle
• Greater focus on compliance and product testing

How do you protect concrete against fire?

Concrete is a major component of many buildings constructed in the UK, both in new developments and renovation projects. While concrete does provide a degree of natural fire resistance, as noted previously, in the event of a fire exposed concrete can experience both mechanical and chemical changes. These include the potential for explosive spalling where portions of concrete delaminate from the surface layer, and external cracking caused by thermal expansion and the dehydration of the concrete – in both cases allowing the direct heating of exposed reinforcing steel (rebar). At temperatures more than 260°C rebar will progressively lose its tensile strength, resulting in the potential structural failure of reinforced concrete.

With this in mind, the need to protect concrete against fire should be a significant element of the fire strategy of a building.

Two effective methods to increase the fire resistance in concrete structures are coatings, for example intumescent paints or sprays, and fire protection boards.

More information on PROMATECT®-H

For more information on PROMATECT®-H boards and other Promat passive fire protection products, [For more information on PROMATECT®-H boards and other Promat passive fire protection products, get in touch with the Promat team.