PR 35043
24 March 2015

Fire safety in public buildings
By Jeff Dyson, Nullifire 
 
Pictured is the British Museum 

Accessibility and openness are concepts at heart of the design process for almost all types of property used by the general public; from libraries and theatres through to leisure centres and shopping complexes.

People like space and light, while architectural consultants are, in general, just as keen to make dramatic visual statements: often expressing the building structure in their interior treatment and avoiding the creation of compartments. All of which is fine on an aesthetic level, though it can pose significant challenges in terms of building services, security and keeping the building occupants safe from fire.

Fire disasters have become relatively rare occurrences in this country as we have learned terrible lessons over such risks as allowing rubbish to build up beneath escalators and sports stadia, or allowing fire exits to be kept locked. Our construction codes of practice and fire regulations have also played a pivotal role in reducing the levels of risk. Further to this, consultants today have a huge selection of ‘passive' or non-combustible materials at their disposal, as well as the availability of active fire protection measures.

Nevertheless, each new publicly accessible building that is constructed or converted must be the subject of a rigorous fire engineering process, with all elements being considered both in isolation and as part of an integrated assembly that must be capable of both safe evacuation, and also facilitating the work of the fire and rescue services should it become necessary.

Maintaining the integrity of escape routes and staircases will be integral to this strategy, but just as important is safeguarding the stability of the main building structure, so that there is no chance of premature collapse as occurred so catastrophically with the Twin Towers in the 2001 terrorist attack.

For although steel remains our strongest and most versatile material - able to accommodate tensile, compressive and other forces - it will always be vulnerable to the extremely high temperatures which occur in blazes, particularly if accelerants or combustible substances are present in any quantity.

It is possible to encase universal columns and beams as well as other steel sections in fire proof boards, or using cementitious sprays. However, such clumsy boxing arrangements or ‘moonscape' finishes are not attractive to either designers or the paying public.

By far the most acceptable approach is to utilise a modern high performance intumescent coating system capable of providing 30, 60, 90 or 120 minutes fire protection. Thanks to their advanced formulation, a system which is normally applied in three coats, not only creates an attractive finish - available in a full range of RAL colours - but when subjected to high temperature starts to expand rapidly in a charring process. This then insulates the steel and prevents it from softening and distorting.

Although reputable systems come to market after exhaustive research and development programmes, and are backed by independent accreditations, their performance remains very much reliant on the standard of workmanship. Therefore specifiers and building owners must only appoint approved applicators who have been trained in the use of the system selected.

Significantly some systems are also capable of being applied to structural steelwork before the erection process is fully completed and prior to the external envelope being made weather-tight. This means the building structure can be protected against the risk of fire during the vulnerable construction phase, often when welders and other trades are employing hot processes which might cause an outbreak of fire.

Another advantage to utilising a modern water-borne system such as Nullifire's S707 range is the absence of solvent smells. Whereas the original solvent based products typically contained 200 g/litre of VOCs and would give off fumes for a long time after application, the water based option is down around 20 g/litre, and can therefore be sprayed in quite close proximity to where other trades are working.

In fact the ease of application and flexibility of use, combined with the inherent weather resistance of the modern intumescent coating means they can actually remove the fire protection of steelwork from the critical path for some construction programmes.

It remains, however, one of the most crucial aspects to the design process for commercial and public buildings - a duty of care where construction consultants simply cannot cut corners. Nullifire therefore offers specifiers the support and confidence of a comprehensive technical advisory service with the chance to gain competitive quotes from the manufacturer's network of approved applicators.

For further information on tremco illbruck, please visitwww.tremco-illbruck.co.uk

-ends-

With compliments:
Alison Relf
Taylor Alden Ltd
Unit 2 Temple Place
247 The Broadway
London
SW19 1SD
Tel: 020 8543 3688
Email: alison@tayloralden.co.uk