Inspecting passive fire protection

Share on facebook
Share on twitter
Share on linkedin
Share on email
Share on whatsapp
Share on print

The Association of Specialist Fire Protection has produced a guide to assist Fire Risk Assessors as ASFP Technical Officer Niall Rowan explains…

Fire safety legislation in the UK is designed to save lives in the event of a fire. As a result, the legal requirements for Passive Fire Protection (PFP) are aimed at ensuring that, in the event of fire, the occupants of a building can escape, fire will not spread easily within a building or to other buildings, the fire and rescue service can attend safely and the building will not collapse prematurely.
 

Since PFP products are those ‘built-in’ to the fabric of a building to restrict the growth and spread of fire and smoke, they are often difficult to identify and inspect. The ASFP Guide to Inspecting Passive Fire Protection for Fire Risk Assessors has been produced to assist Fire Risk Assessors to carry out inspections of PFP as part of a fire risk assessment under UK fire safety legislation. It provides Assessors with appropriate guidance for them to be able to verify that the PFP supporting means of escape is adequate and will perform as expected to ensure that life safety is never compromised.
 

PFP products work to control the flammability of wall and ceiling linings, divide the building into fire resisting compartments, provide protection to the structure of the building to prevent its collapse, and provide protective routes for escape. PFP products include : Fire doors, fire resisting walls, floors and ceilings, fire resisting ducts and dampers, fire stopping and fire protection to structural members.
 

Whilst a full investigation of all PFP would be the ideal; it is generally not necessary for a fire risk assessment under the current legislation. The aim is to ensure that the means of escape is not compromised by deficient PFP and that the spread of fire and smoke is restricted. A fire risk assessment should thus typically consider:
 

Lining materials for wall and ceilings on escape routes

Fire doors – especially those serving escape routes

Construction of walls, ceilings and floors forming escape routes

Penetrating services in walls ceilings and floors forming escape routes e.g. ducts, pipes etc.

 

There is much guidance on this from trade associations and other organisations. Whilst this is useful background information it tends to comprise rather more in detail and quantity than is required for a risk assessment under the legislation. It is also spread over many different publications, in different formats and in different levels of complexity. The ASFP guide provides sufficient guidance on what to look for in relation to all types of PFP in a single document, thus enabling the Fire Risk Assessor to adequately evaluate PFP without constant reference to a large number of specialist guidance documents.

 

Evaluating the PFP

The Assessor needs to evaluate what is needed for occupants to escape in the event of a fire and then evaluate the PFP accordingly. The assessment needs to be balanced, taking into account the occupation and purpose of the building, its age and construction, as well as the building layout. It should consider the life safety fire strategy for the building and the extent to which fire resisting construction on escape routes and fire compartmentation contributes to that.

 

Age of the building

The age of the building is also important in evaluating the PFP of existing escape routes. In older buildings it is possible that the type of construction and materials used may not perform to current fire test standards. Changes of occupier and/or refurbishment may have led to the creation of cavities and voids, allowing the potential for fire and smoke to spread unseen.

 

In more modern buildings it is likely that there will be fewer unsealed voids; cavity barriers should have been installed where appropriate and any breaches in fire-resisting construction e.g. for the provision of services should have been adequately fire-stopped.

 

Irrespective of the age of the building the Assessor should be alert for breaches in all types of fire resisting construction and/or inappropriate fire stopping and record these as part of his risk assessment. If his survey indicates that there may be significant breaches in difficult to survey locations, the Assessor should not be afraid to recommend a more invasive inspection by a specialist third party inspection organisation. B

uilding layout

 

To be able to decide on the appropriate level of PFP and evaluate it, the Assessor must familiarise himself with the building layout and escape routes. If a Fire Strategy document exists this should provide the required information and should be considered with the building drawings. The ASFP guide indicates where such information can be found and what the legal basis is behind its formulation and retention.

 

Such information should include details of fire resisting construction on escape routes, fire compartmentation and other PFP information and should include where appropriate fire test and assessment reports and any third party certification. The use of third-party certificated products and installers should confirm to the Assessor that all installed penetrations are effective as these installers are regularly audited by the certification bodies. However, this will not necessarily reduce the amount of inspection required as the Assessor will need to confirm that additional penetrations have not been made since the PFP was installed.

 

For older buildings, or those where the information is not available, the only way to determine the escape routes and critical compartmentation may be a survey of the building layout, from which the assessor will have to decide on what level of PFP/fire resisting construction is appropriate. From this, a document that lists the escape routes and where fire-resisting construction is required can be created, as a basis for checking the PFP as part of the risk assessment. The ASFP guide provides sensible guidance to fire risk Assessors including what considerations need to be made for a number of building type/occupancy scenarios.

 

Guidance on each type of Passive Fire Protection

Once the Assessor knows where and what he is going to survey, he needs guidance on the pertinent features of each type of PFP to be inspected. The ASFP guide provides this in short, easy to digest sections. A checklist is provided for each type of PFP to enable the salient points to be recorded.

 

If the Assessor needs more detailed information on a particular type of PFP e.g. fire doors, then there is a detailed annex for each type of PFP, with this information including links and references to the relevant in-depth publications by the appropriate trade association.

 

The five main types of PFP that need to be assessed are:

 

Lining materials for wall and ceilings on escape routes

 

The surfaces of any walls and ceilings in escape routes should be inspected to see if the materials forming the linings are satisfactory and that any additions e.g. extensive areas of notice boards, posters, carpets etc. do not cause a hazard by aiding rapid fire spread along a corridor.

 

The materials and construction of the walls and ceilings themselves should be satisfactory as these should have been checked in the building control process. However, older buildings, or those where there have been recent changes e.g. after occupation, will need to be checked.

 

Fire doors

Fire doors are crucial in protecting the means of escape in any building. Regulatory guidance recommends doors which satisfy integrity for 20, 30, 60 or 90 minutes. These times are a good basis for new-build, but are not ‘carved in stone’. A Risk Assessor may consider that for some buildings, existing doors of a lower period of fire resistance are satisfactory or conversely, that doors of a higher performance may be needed to contain the risk. All fire doors in the building should be inspected. These should be easily identified as fire doors and marked accordingly.

 

Construction of fire resisting walls, ceilings and floors forming escape routes

For most older buildings, it should not be necessary to extensively evaluate the fire resisting construction used in escape routes or in compartmentation as these should have been covered by the building control process. For example in an office building, the number and construction of the floors (which will often be concrete) are unlikely to change. In more modern buildings, changes in fire resisting construction of walls and floors may occur where the internal layout has been changed e.g. by relocating, replacing or demolishing internal partitions. In this case, the Fire Risk Assessor needs to verify that the new construction is still suitable for use as an escape route in two regards; layout and type of construction.

 

The Fire Risk Assessor needs to check that any modifications have not affected the means of escape, for example, significantly increased travel distances, or removed some of the fire doors. The Assessor will need to check that the type of construction used in any replacement construction is suitably fire resisting.

 

Suspended ceilings often play a role in the fire strategy of the building and should also be carefully inspected, since it is easy to downgrade a ceiling from the original intended fire rating e.g. by the fitting of untested downlighters. If compartment walls which have not been taken floor slab to floor slab, fire can spread via the ceiling void.

 

Penetrating services

If a fire separating element is to be effective, every joint or imperfection of fit, or opening to allow services to pass through the element, needs to be adequately protected by sealing or fire stopping so that the fire resistance of the element is not impaired. The provision of fire resisting walls, ceilings and floors forming escape routes is most commonly compromised by the installation of penetrating services through the wall or floor. These include cables and pipe; ducts and dampers; and support for penetrating services.

 

In new buildings, the Building Regulations address this by requiring the inclusion of suitable fire stopping. However, this is sometimes compromised by: use of poor quality products; poor quality/lack of installation; or the addition, removal or modification of penetrating services after the building is completed without correct reinstatement of the fire stopping.

 

Other items of PFP

The Assessor should be aware of other items of PFP installed in the building and take note of their condition to ensure that there are no obvious significant defects. These include :

 

Fire protection to the structure of the building

Cavity barriers

External fire spread

Sandwich panel construction

 

While these other items may not constitute means of escape, they have a role to play in the provision of life safety and, for example, any substantial omissions or defects should be noted.

 

A valuable tool

The ASFP Guide to Inspecting Passive Fire Protection for Fire Risk Assessors is a valuable tool for the Fire Risk Assessor in enabling Passive Fire Protection to be adequately evaluated as part of a Fire Risk Assessment under the legislation. It provides the Assessor with all the essential information in one easy to use document. The ASFP hopes that in simplifying and clarifying the approach to examining PFP, Fire Risk Assessors will undertake assessments that fully encompass and embrace the principles behind PFP.

 

Subscribe to our newsletter

Don't miss new updates on your email