The LWF Blog

Facilities Management & Fire Safety – Foam Systems – Part 20

August 10, 2017 1:21 pm

In this blog series for those who work in Facilities Management and have a responsibility for or interest in Fire Safety, we have been looking recently at Water Mist Systems and how they first came into use for the protection of ships and their cargo many years ago, through to the present day expansion in their use to residential buildings and the resulting British Standards that were recently produced. In Part 20, we’re going to look at the use of Foam Systems and the specialist applications to which foam can be put.


The composition of foam for fire safety purposes is almost as simple as you might imagine. It’s a combination of water, air and a suitable foaming agent.

Low and medium expansion foam systems are primarily found in special risk areas such as those where flammable liquids are in use or are stored. Foam systems are not often found in general use buildings except potentially, if there is an oil-fired boiler.


High expansion foam systems have the purpose of entirely filling the protected area with foam and are most often found protecting class A risks. A high expansion foam system is most often found in those areas which cannot be accessed by conventional fire-fighting methods and have also been known to be used to protect underfloor areas of computer suites, for example, although it is more common to find them used on board ships, in aircraft hangars and other high-risk, non-traditional environments.


As of 2017, the most up to date guidance available in reference to foam systems is BS EN 13565-2:2009 Fixed firefighting systems – foam systems. Design, construction and maintenance. This document gives information on the design of such systems to ensure they are entirely appropriate for purpose, as each system must be individually designed.


Not all foam systems are designed to simply fill an area with foam, there are two particular types – aqueous filmforming foam (AFFF) and filmforming fluoroprotein foam (FFFP) – which can be released into an area via a sprinkler system to provide additional protection in certain environments. This might be most useful in an environment where there are large amounts of low-flashpoint flammable liquids. In this instance, the sprinkler system would be a conventional installation with the addition of facilities to introduce the foam liquid into the water supply as and when required.


In Part 21 of this series, we will begin to look at how Gaseous Systems work and under what circumstances they should be used as part of a building’s fire protection plan. In the meantime, if you have any queries about your own facilities or wish to discuss this blog series, please contact Peter Gyere in the first instance on 0208 668 8663.


Lawrence Webster Forrest is a fire engineering consultancy based in Surrey with over 25 years’ experience, which provides a wide range of consultancy services to professionals involved in the design, development and construction and operation of buildings.




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