There are many elements to consider when attempting to prevent and control fire within the built environment.
The triangle of fire is a well-recognised and understood model for determining the constituent parts necessary to create and sustain a fire. If any one of the three key elements – oxygen, heat or fuel – is missing then a fire simply cannot take hold. If any of the three elements is removed during an established fire, for instance by cutting off the air supply, the fire will go out.
To a greater or lesser degree all buildings will contain sufficient quantities of all three of the above ingredients to enable a fire, with its associated hot smoke and gases to occur. The extent to which any such fire will develop and spread will be governed by a second triangle, which I call the ‘triangle of construction’. This triangle is also made up of three essential elements, those of design, construction and maintenance.
Provided that those responsible for each one of these essential elements ensures that the fire provision within their remit of responsibility is undertaken in an appropriate manner, then it is reasonable to assume that the development and spread of a fire will be held to a minimum. However, if for any reason one of these processes should prove inadequate, it is probable that the growth and spread of fire and its associated components will be significant, irrespective of whether the other elements of the triangle are seen to be ‘fit for purpose’.
Such a ‘triangle of construction’ is of course the polar opposite of the ‘triangle of fire’, in that; failure within any one element will actually lead to a fire spreading rather than result in it being extinguished. In reality of course, fires will always happen either by unfortunate circumstance or as a deliberate act. Therefore the issue to be addressed is, how can such fires be controlled once ignited to minimise risk to life and property?
Each group defined within this ‘triangle of construction’ has a duty to ensure that, in the unfortunate event of a fire, they have taken the necessary steps to ensure that their responsibilities in relation to fire safety have been fully met. What does this mean in practice?
Building Design – the First Side of the Triangle
It could be argued that fire protection, be it passive or active, could be construed as a grudge purchase, adding nothing to the aesthetics of a building and often perceived to be very expensive!
Regulations lay down a basic set of parameters in relation to life safety in the event of a fire and are not intended to offer protection to the building. Yet, even these basic mandated levels of protection are often seen as a challenge to value engineer down to a minimum or, in some cases, engineer out altogether.
The design process can also lead to weaknesses in the completed construction. A tendency toward design and build means that the design of fire compartments, for example, and the services passing through them are often inadequate. As a result, divisions are poorly thought out and the fire-stopping contractor often has to sort out an inherited mess, with common issues including: mixed services passing through the same wall; fire dampers that are not in the plane of the wall/floor; and the use of inappropriate products and materials. In addition, he frequently has to work in an environment with insufficient access, which makes doing his job very difficult.
Proper design of divisions and planning/sequencing of the work is critical to ensure the compartmentation is adequately provided. The Association for Specialist Fire Protection (ASFP) has recently published its Technical Guidance Document 17: Code of practice for the installation and inspection of fire-stopping. This publication stresses the importance of adequate design and planning and can be downloaded from http://is.gd/FCjaV1.
When it comes to appropriate building design, granted, the award-winning façade is important and its green credentials essential, but not by trading off investment in vital fire safety provision. Removing or downgrading essential fire protection measures from the design, may result in all other attributes having no relevance at all should the building be razed to the ground by fire. It is critical that any building design adequately reflects its fire protection needs, and this means an effective fire compartmentation strategy.
Building Construction – the Second Side of the Triangle
Within the UK and many other parts of the world there is no mandatory requirement calling for fire protection measures to be installed or undertaken by a competent person or via a third-party certificated process.
Lack of appropriate knowledge both by those that procure fire protection installation services and those that claim to offer such services without a recognised standard of competency, can and does lead to inappropriate installations. If not detected, these will result in a building that is not fit for purpose in terms of smoke and fire performance.
If you are involved in the provision of fire protection, at any level, then you share liability for its usefulness and its operation when it is needed in fire, and that liability will still be there in the event of a court case. If it is your responsibility to specify materials and/or appoint the installation contractor, it is also your responsibility to ensure that they can prove competency for the fire protection materials used, or the works to be carried out. If you are a manufacturer of fire protection products, it is your responsibility to show that they are fit for purpose and will provide the required fire performance, usually through a rigorous programme of fire testing and third party certification. Likewise, if you are an installer of fire protection systems it is of equal importance that you can demonstrate your level of competence.
From an ASFP perspective, a competent person is one who can demonstrate to a third party that they have the expertise, skills and commitment for the professional installation of passive fire protection products, which means one who either:
- Works for a third-party certificated installer under the conditions of that scheme; or
- Within the UK has demonstrated to a certification body running a UKAS-accredited competent person scheme to EN ISO 17024 (Personnel Certification), competence in the installation of passive fire protection.
Those fire protection installers that have achieved third party certification status are required to use trained staff whose competence has been evaluated, whose records are subject to audit by the certification body and whose work is subject to random inspection by qualified inspectors. All ASFP contracting members must have attained appropriate third-party certification status before they can become a member of the Association. Many clients, specifiers, enforcement authorities and others responsible for fire safety, such as the Responsible Person under the Regulatory Reform (Fire Safety) Order, also now recognise that to allow installers to self-certify their own work is not considered sufficient or acceptable.
Construction & Maintenance – the Third Side of the Triangle
Over the lifespan of any building, many changes are likely to be made, not only to the existing fabric of the building but through its potential change of use, essential maintenance and updating or expansion. It follows therefore that on-going and regular assessments of the fire safety measures within a building are undertaken to ensure that appropriate fire safety provision is maintained.
Risk assessment for passive ‘built-in’ fire protection is often not a straight-forward exercise. Many of the fire protection measures involved, such as the make-up of the fabric of the envelope of the building, or at a smaller scale, the detail of the fire stopping measures, may not be determined by an ‘on the ground’ visual inspection. Often such measures may be hidden above a suspended ceiling or within a cavity and, in some cases, may even be sited inside other components not obviously recognised as fire protection – for example, a fire damper within an air ventilation ducting system.
Many follow-on trades may unwittingly destroy essential fire compartmentation provision, since, to the untrained eye, a hole in the wall may just be seen as a maintenance issue.
The following factors can affect the in-service performance of such products or systems:
- In-service Environment.
The nature of the environment to which the product or system will be exposed may affect its durability or performance in a fire situation.
- Planned Maintenance, Records & Reports.
In most cases, correctly applied or installed passive fire protection products or systems used internally in buildings should not require significant maintenance over the design life of the building, other than where mechanical damage or subsequent modification has occurred. However, periodic inspections should be carried out as part of the normal maintenance plan for the building with any damaged passive fire protection measures either replaced, or where appropriate, repaired in the same way as in the original manufacturers’ specification.
In some cases, it may not be possible to replace or repair with the same manufacturer’s products, since the originally installed product may no longer be available. In such cases, a professional opinion should be sought before mixing and matching materials and products from different manufacturers. Some features, such as fire-resisting ducts and fire doors, will require regular operational checks. Fire dampers, for example, should be inspected and operated at least annually and fire resisting ducts should be checked for the build-up of grease/rubbish.
Keeping detailed and accurate records is vital and should be seen as an essential management requirement.
- Refurbishment or Upgrading of Passive Fire Protection Measures.
The ASFP recommends that the refurbishment or upgrading of fire protection systems shall always be carried out in accordance with the advice of the system manufacturer, and installed by a specialist third party certificated contractor.
Given the arguments expressed above, it is clear that there are many essential elements to consider when considering fire safety within the built environment. Controlling the elements in the triangle of fire will prevent a fire from starting or help to extinguish it; while controlling the elements within the triangle of construction will prevent the spread of fire and smoke.
Look for the Logo
The Association for Specialist Fire Protection comprises manufacturers and installers of passive fire protection products and systems. To be a member, manufacturers are required to hold third-party product certification for any products that are listed in ASFP publications. ASFP contractor members are required to hold third-party certification for the installation of such products. The assurances gained by using an ASFP manufacturer or contactor will ensure the installation of passive fire protection that is fit for purpose. Look for the logo.
The Association for Specialist Fire Protection offers detailed guidance on fire testing, specification and installation of the following passive fire protection groups:
- Structural steel fire protection.
- Fire stopping, fire seals and cavity barriers.
- Non load bearing partition systems.
- Fire retardant coatings.
- Fire resisting ducts and dampers.
- Fire resisting walls and linings.
- Fire risk assessment of passive fire protection.
For further information, go to www.asfp.org.uk