Peter Jennings, Technical Director for ACO Building Drainage, highlights the potential problems of inappropriate drainage systems in relation to fire safety and how the latest gully technology is helping to reduce the risks.

In recent years there have been a number of high profile disasters where public and commercial buildings have been destroyed and lives lost as a direct result of fire and fumes spreading rapidly via conduits and drainage systems.

Perhaps the worst case is that of the devastating and tragic fire that killed 16 people and left over 100 injured at Düsseldorf Airport in Germany on 12th April 1996. The fire was caused when hot glowing particles from a welding operation dropped onto a part of the building where PVC cables and insulation materials immediately caught fire. As a result, flames, smoke and noxious fumes then broke into the cable ducts and drainage gullies and spread throughout the entire building.

Critically, the main problem here was caused by the use of PVC, which is incredibly flammable and generates high volumes of toxic gases. However, the point remains that the ducts and gullies running between the floors offered an unobstructed route for flames and fumes to be sucked or blown through narrow passages, causing a Venturi effect and dangerously speeding up the flow dramatically.

In the wake of the much publicised fire, which was undoubtedly the worst in the history of German airports, the building was completely modernised and, most importantly, all the PVC was replaced with alternative materials. The tragedy also raised awareness of how a building’s drainage system can cause the problems of a fire to escalate rapidly, ultimately with catastrophic effects. Indeed, the danger is now recognised widely in Germany and standards have been introduced that make it essential for appropriate gully protection systems to be installed in public buildings, such as hotels and offices.

However, although the problem is understood in Germany, in other European countries, including the UK, there is still a lack of widely recognised and appropriate universal standards for companies to work to. As a result, many buildings, especially older buildings, rely on traditional sprinkler systems or fire barriers to prevent the spread of flames and fumes.

To address this issue, leading manufacturers have introduced a new generation of fire gully systems that have been developed to block effectively the passage of heat and, more importantly, smoke and noxious fumes.

For example, ACO Building Drainage has developed the Selecta range of floor drainage gullies that reduce the risks and aid in the compliance of the Regulatory Reform (Fire Safety) Order. In addition, this range is one of the remarkably few systems available on the market that are designed and manufactured to BS EN 1253 meaning that they can be installed without the need for further performance and safety testing.

This latest generation of gullies are manufactured from cast iron and sited within a thermally insulated pre-formed concrete jacket to provide effective fire containment and limit thermal transmittance. Typically they feature an intumescent fire cartridge, tested in accordance with BS EN 1366 Fire Resistance Tests for Service Installations, which significantly reduces smoke transfer to other floor levels in a building as well as limiting oxygen paths that feed fire. Indeed, when this component expands at approximately 150°C, it closes off the gully void completely.

Thankfully, this latest gully technology offers a solution that is both effective in preventing the spread of fire, as well as being quick and simple to install, while also being a particularly cost effective solution.