Select Committee on Environment, Transport and Regional Affairs Minutes of Evidence

Memorandum by The Fire Brigades Union (ROF 28)


  1.1  The Fire Brigades Union welcomes the opportunity to make a submission to the Environment Sub-Committee regarding the above mentioned matter. The question of external cladding systems and the problem of fire spread along the vertical surfaces (walls) of a building is one that has concerned us for some time.

  1.2  However, in referring to external cladding systems the Sub-committee need to be aware that there are many types made from many dissimilar materials with differing fire performance characteristics available in the building materials market place. They may range from various types of;

    —  impregnated or treated timber or timber based building boards; or

    —  plastic based (glass fibre reinforced plastic, rigid upvc, etc.) pre formed boards; or

    —  insulated sandwich panels, being a finished panel of 50 mm to 100 mm thick formed with an outer skin of building boards, metal sheet, etc, and a core of foamed plastic insulant, or blown glass, or mineral wool.

  1.3  External cladding systems may be installed to meet a range of requirements and tasks. The primary tasks for which installation may be recommended, that we have identified, are as follows:

    —  as a decorative system to enhance the appearance of a building; and

    —  as a decorative system offering enhanced weather protection to the building to which they are fixed; and

    —  as a decorative system offering both enhanced weather protection and insulation to the building to which they are fixed; and

    —  as a weather protection system; and

    —  as a system to improve the insulation and thus heat retention properties of an existing building; and

    —  as an infill system for replacing floor to ceiling window areas prior to fitting double glazing window systems.

  1.4  In our opinion, the most likely reason for fitting an external cladding system to an existing building will be to improve the weather protection and insulation of the building to which they are fixed. This is particularly so in the case of multi storey flats built in the 1960s and early 1970s using the reinforced concrete panel building systems that were popular with the construction industry at that time.

  1.5  Some of these buildings have not withstood the test of time particularly well and have proved unpopular with tenants for a variety of reasons, not the least being persistent condensation problems inside the flats and high heating bills. Both problems being caused primarily by the lack of thermal insulation, other than that offered by the concrete panels themselves.

  1.6  Local authorities, housing associations and some private developers who have responsibility for such properties have therefore, sought to improve their older multi storey housing stock by attaching light weight cladding systems offering high insulation values, improved weather protection and often a more attractive finish, to the external faces of such buildings.

  1.7  At the same time they have usually retrofitted double glazing and installed improved internal sound insulation plus cost effective central heating systems.


  2.1  There are a number of risks that may be posed by the use of combustible, or badly installed, external cladding systems. Having said that it should be understood that cladding systems themselves are unlikely to be the first item that is ignited. They are far more likely to become involved in fire as a result of a fire in a room that has vented through the room window(s) and which is travelling up the building face. This is a common occurrence and is predicted by the laws of physics (ie, heat rises therefore fire travels upwards).

  2.2  The primary risk therefore of a cladding system is that of providing a vehicle for assisting uncontrolled fire spread up the outer face of the building, with the strong possibility of the fire re-entering the building at higher levels via windows or other unprotected areas in the face of the building. This in turn poses a threat to the life safety of the residents above the fire floor.

  2.3  A secondary problem of fire spread through external cladding may be caused by the method of fixing the panels to the exterior facade of the building. If lightweight fixings (aluminium or metal alloys, etc) or resin bonded systems are used to attach the panels. There is a risk of the panels becoming detached when exposed to fire and falling from the face of the building posing the associated missile risk to firefighters and members of the public in the vicinity of the building.

  2.4  Fires involving fire spread via external cladding have occurred before however, in the short time available to create this response it has been impossible to obtain comprehensive details of dates, times and places. No doubt the Home Office—Fire and Emergency Planning Directorate (FEPD) and the Department of the Environment, Transport and the Regions—Building Regulations Division (BRD) will have the details. A well-documented and well-researched fire of this nature was the Summerland Leisure Centre fire in Douglas on the Isle of Man in 1973.

  2.5  We have long been concerned regarding the lack of fire resistance required for external cladding particularly in high rise (over 30 metres in height) buildings. The risk of a fire involving cladding in such buildings is no greater than in any other building however, what is different is the ability of the fire service to gain access to the fire to deal with it.

  2.6  Fire service turntable ladders and hydraulic platforms will only give firefighters external access to a height of around 25 metres, although some brigades have aerial appliances that will give higher access these are relatively few and far between. Similarly inbuilt firefighting facilities provided for the fire service to use above 30 metres are all designed for firefighting within the building.

  2.7  This means that firefighters must enter the dwellings above and below the fire and fight the fire from balconies or windows if they are to have any chance of stopping the fire spreading vertically up the entire face of the building. This can be extremely difficult and hazardous as those below the fire front may have flaming debris falling upon them, whilst those above the fire will be looking straight down into the flame front and will be enveloped in the smoke cloud. They will also have to deal with any accommodation that is on fire in the building.

  2.8  If the flame front gets past them then the probability is that it will re-enter the building through window openings or balconies higher up the building and consume the contents of those rooms thus becoming self perpetuating. This fire scenario is known as "roll up" because the fire rolls up the building jumping from floor to floor through window and balcony openings and can occur whether or not cladding is present.

  2.9  Fires involving external cladding will probably be caused by a fire in the accommodation breaking out through a window or balcony and the flame front affecting or involving the cladding system as it rolls up the building face.

  2.10  The real problem is that any external cladding above the fire is likely to be exposed to flame front temperatures in excess of 900C upon failure of the window if that failure causes the fire room to flashover. Window frame failure may also cause disruption of the external cladding if it is tied to it.

  2.11  It is for these reasons that we believe that all cladding used on multi-storey buildings over 25 metres in height and the fixing systems should be completely non-combustible, or achieve a fire resisting standard equivalent to the external walls.


  3.1  It is hard to attempt to quantify this information, as it will rest with those who own premises that have external cladding systems fitted. Certainly, we know of a number of local authorities who have used external cladding to upgrade and improve their residential properties and particulary the reinforced concrete panel system high rise flats.

  3.2  Sandwich panel type systems are also proving popular in the industrial sector, particularly in the food production and cold storage industries where the use of internal sandwich panels is widespread.


  4.1  The primary method of controlling the fire risk of building products when used in works of construction is through the medium of the Building Regulations in England and Wales, or the Building Standards in Scotland. Enforcement of the Building Regulations or Standards lies with local authority Building Control Departments.

  4.2  The Building Regulations in England and Wales and the Building Standards in Scotland do place requirements in terms of the fire spread upon external cladding systems through the imposition of technical requirements which reflect the following principles:

    —  that fire should not be able to spread easily through the use of such a system, generally such systems should be of limited combustibility;

    —  it should be noted that limited combustibility does not mean non-combustible (ie unable to burn) it means that the cladding should not propagate fire easily and then only in accordance with prescribed limits;

    —  where a building is close to another so much so that a fire in one building may cause the other building to become involved due to exposure to radiated heat then the cladding should be fire resisting;

    —  the external wall upon which the cladding is mounted should be fire resisting; and

    —  where the cladding has an air space behind it between its rear face and the face of the wall the gap so formed should be fire stopped to prevent fire spreading behind the cladding.

  4.3  Only in one instance, that is where the building is within the notional boundary (close proximity) of another building, is there a requirement for external cladding to be fire resisting.

  Unfortunately, this requirement rarely bites as we do not tend to build multi-storey buildings less than two metres apart.

4.4  Fire Testing External Cladding Systems

  The British Standard test that predicts whether a product is of limited combustibility is BS 476 Part 11—1982.

  BS 476—Part 11 is a small scale test conducted under laboratory conditions. The test seeks to establish a temperature rise from the burning of the specimen in a furnace and also the duration and exent of any flaming. It sets limits which five specimens supplied by the applicant must achieve to pass the test. It is not particularly suitable for composite or bonded materials.

  We have been particularly concerned for some time with the principle of small scale fire testing of large building components such as composite cladding, or insulated sandwich panel systems. We believe strongly that such testing and its findings should be validated by large scale testing of the complete system under realistic fire conditions. However, it appears that the real barrier to large scale testing is the question of cost rather than that of scientific prudence.

  We understand that since 1991 work on a more realistic test has taken place and between 1995 and 1996 a new test procedure for external cladding systems was developed jointly by leading board manufacturers and the Fire Research Station. This is entitled "A Test Method to Assess the Fire Performance of External Cladding Systems" and we also understand that it was submitted for acceptance by the DETR, but nothing has since been heard on its progress towards adoption.

  What ever happens in the future, we believe that the existing small scale test method is unsatisfactory and that a new test for both internal and external cladding systems and sandwich panels should be developed which should be based on the ISO 9705 Room Corner Test.


  5.1  This question really asks two questions, being:

    (a)  what can we do about existing systems already in use; and

    (b)  what should we do to prevent unnecessary risks with such systems in the future?

  5.2  In the case of existing premises already fitted with an external cladding system it seems a case of establishing the size of the problem and dealing first with those presenting the greatest risk to their occupants. It would seem logical to carry out inspections of all high rise residential premises fitted with external cladding systems to ensure that they conform to the current Building Regulations or Standards. Where they do not then they should be either upgraded, or replaced, to that standard as a matter of urgency.

  5.3  For low and medium rise residential developments or one and two storey domestic properties, unless they are premises housing the elderly, or disabled, which should automatically be classed as high risk priority, it would seem logical to inspect the cladding systems used to ensure they conform to the current Building Regulations or Standards and where not introduce a phased replacement or renovation programme.

  5.4  In all cases on site inspections should identify whether a fire involving an external cladding system might jeopardise the means of escape in case of fire from the building. Where it is found on inspection that the use of external cladding may affect the means of escape from the building in case of a fire involving it then immediate remedial action should be undertaken.

  5.5  All inspections should be jointly carried out by fire service officers of the fire authority and building control officers of the relevant local authority.

  5.6  In the case of new buildings or alterations to existing buildings then we believe that the following requirements should apply:

    —  in buildings up to 25 metres in height all external cladding used should be of limited non combustibility and the fixtures should be capable of retaining the cladding system in place for at least one hour when exposed to a fire, any infill panels should afford the same fire resistance as the walls surrounding them; and

    —  in buildings over 30 metres in height all external cladding or infill panels should be inherently non combustible, or afford the same fire resistance as the walls to which it is attached; and

    —  a new large scale fire test for all cladding and sandwich panels should be introduced by the DETR and British Standards Institution as soon as possible.


  6.1  We believe that the role of the Building Regulations Advisory Committee (BRAC) in this matter and generally as to its constitution and working practices should be discussed by the Sub-committee. BRAC exists to offer guidance to the Secretary of State upon the content and application of the Building Regulations in England and Wales. In Scotland a similar body called the Building Standards Advisory Committee, or BSAC also exists.

  6.2  Members of BRAC are nominated by professional bodies, or associations, but are appointed on a personal basis by the Secretary of State for Construction at the DETR, currently Nick Raynsford MP. They are then asked to sign the Official Secrets Act and theoretically from that point on they should not discuss any matters they may collectively consider with anyone else, including their nominating bodies.

  6.3  This secretive procedure has caused some concern in the fire industry, as fire risk matters that we may identify, such as the fire risks of sandwich panels and external cladding systems, are submitted to the DETR who pass them to BRAC where they are apparently considered in closed session. Having done so BRAC then send their conclusions back to the DETR who seem to then issue a public consultation document on what they perceive to be the best way forward.

  Once that public consultation process is complete BRAC then consider the responses received, before coming to their final conclusions, which in turn becomes their advice to the Minister.

  6.4  As an example, in December 1997 the Building Regulations Division of the DETR undertook an extensive public consultation exercise upon amendments that BRAC proposed to Approved Document B (Fire). Approved Document B is the guidance document to discharging functional requirement B (Fire) of the English and Welsh Building Regulations. Since closing the consultation exercise in March 1998 the 170 plus responses received, have been analysed at the Building Research Establishment (BRE) and the outcomes passed to BRAC for consideration.

  6.5  As yet and some 19 months later, no announcement has been made on the final proposals which will, when published, amend the English and Welsh Building Regulations for at least the next five years. We understand that BRAC has now concluded its deliberations and their advice has now gone to the Minister, with an announcement being likely in November of this year.

  6.6  Secretive processes and delays of this nature only serve to bring the process of government into question and given that this government is committed to a far higher degree of openness than its predecessors we are surprised and disappointed that the government permits BRAC to continue to work under a cloak of secrecy.

  6.7  By comparison, Health and Safety Commission Committees and the Central Fire Brigades Advisory Council operate an open system of meetings that is much more in line with a policy of open government and enables interested onlookers to keep abreast of current thinking at a government departmental level.

  6.8  We believe that the constitution of the Building Regulations Advisory Committee should be amended and reformed to permit it to become an open committee whereby it's discussions and deliberations are in the public domain.

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