Memorandum by The Fire Brigades Union
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
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
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. WHETHER A
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 OfficeFire
and Emergency Planning Directorate (FEPD) and the Department of
the Environment, Transport and the RegionsBuilding 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
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
3. THE EXTENT
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. THE ADEQUACY
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
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
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
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
4.4 Fire Testing External Cladding Systems
The British Standard test that predicts whether
a product is of limited combustibility is BS 476 Part 111982.
BS 476Part 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. WHAT ACTION
5.1 This question really asks two questions,
(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
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
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
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. OTHER MATTERS
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
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.