Grenfell Tower, Neo 200, Lacrosse and the fire safety of facades
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AUSTRALIAN
MO D E R N
BUILDING
AL LI A NCE
Safe and sustainable construction with polymers
Information Sheet 3:
Grenfell Tower, Neo 200,
Lacrosse and the fire safety
of facades
This information sheet explores insulated rainscreen
facade systems in the context of the Grenfell Tower (2017),
Lacrosse (2014) and Neo 200 (2019) building fires, and
the role of product specification, enforcement of building
codes, and the testing and performance of building
systems in managing fire risk in buildings.
Insulated rainscreen facades
In an insulated rainscreen facade If the core is 100 per cent
Exterior wall system the cladding provides the polyethylene, as in the cheaper
Rainscreen Insulation outer protective layer that shields products typically used for
cladding board the exterior wall from direct rain, signage, the panels are highly
while thermal insulation forms an combustible.
underlying separate layer against
Heat from a fire is conducted
the exterior building wall (see
rapidly through the aluminium to
Figure 1).
the thermoplastic polyethylene
The insulation board is typically core, which melts and can
polyisocyanurate (PIR), phenolic ignite, causing the metal skins to
foam or mineral wool (MW) – delaminate and deform.
although the use of MW adds
significant weight to the building.1 Aluminium sheet
Typically, given a constant
R-value of 2.86, MW at 100mm
thickness adds 6kg/m2 to a
DRAINAGE GAP
building, versus 1.9kg/m2 for
60mm of PIR board insulation.
EXTERIOR
INTERIOR
Core
Aluminium composite panel
(ACP) cladding (Figure 2), which
has been used extensively
in Australia and the UK, is a
Figure 1: Simplified schematic composite of two metal skins
diagram of an insulated rainscreen (typically aluminium at 2–5mm Aluminium sheet
facade system (supporting frame
thickness) with a polymer core.
for cladding and cavity barriers not
depicted). Figure 2: Schematic diagram of an
aluminium composite panel (ACP).
1Grenfell Tower (2017)
The Grenfell Tower (Grenfell) fire As noted by Fulvia Raffaelli in her Prior to the Grenfell tragedy, fire
was found to be the direct result 2018 update to the European fatalities in the United Kingdom
of the improper installation and Commission – “The fact that had been declining (Figure
use of an ACP which contained serious fire accidents in the EU 3). Although this trend was
a 100 per cent polyethylene (Grenfell, Bucharest disco) were associated with the introduction
core and did not meet the caused by non-compliance of regulations aimed to improve
local building codes.2 Polymer with existing fire regulations fire safety, none of these
insulation (phenolic and PIR) points rather at the need to regulations related directly to
used behind the rainscreen was enforce existing Member States building products or building
also incorrectly installed as part regulations than at the need for codes.
of the rainscreen facade system, new regulation at EU level.”5
Instead, regulations targeted the
and for this reason contributed to
Although the fire was caused by most common causes of fires
the spread of the fire.
a failure to enforce local building (smoking, cooking, electrical
More broadly, this reflected a codes, the government banned faults) and the household
failure to enforce the existing fire the use of combustible materials materials most often initially
regulations (e.g. non-compliant in walls of high-rise buildings over involved in building fires (Figure
ACP installed on the tower2), 18m such as residential flats, 4). All regulations focused on
unintended consequences of care homes, shelter-housing or either prevention (e.g. furnishings
deregulation (e.g. there was hospitals from 21 December and electrical standards), early
only one fire escape stair in the 2018.6 detection (e.g. smoke alarms),
tower3) and poor procedural escape or suppression (e.g.
policy (e.g. for residents to stay in sprinklers) of fires.
their flats4).
60,000 2000 Escape windows 600
2006 Sprinklers
50,000 500
Number of dwelling fires
Fire-related fatalities
40,000 400
1988 Furnishings
30,000 regulation 300
20,000 1992 Smoke alarms 200
2005 Electrical
10,000 standards and general 100
product regulations
0 0
2
4
6
8
0
2
4
6
8
0
2
4
6
8
0
2
4
6
/8
/8
/8
/8
/9
/9
/9
/9
/9
/0
/0
/0
/0
/0
/1
/1
/1
/1
81
83
85
87
89
91
93
95
97
99
01
03
05
07
09
11
13
15
19
19
19
19
19
19
19
19
19
19
20
20
20
20
20
20
20
20
Dwelling fires Fatalities
Figure 3: Dwelling fires and fire-related fatalities, shown against regulations aimed to increase fire safety, IRS,
England: 1981/82 to 2016/2017.7
216%
Finally, there is no correlation
20%
between fatality rates due to
building fires in the European
Union (EU) and whether the
insulation was combustible Bedclothes Waste
or non-combustible.9 Clothing Cooking oil 6%
Furniture Other
For example, from 2008–2010 23% Paper Unknown
the fatality rate was higher in 5%
Denmark, which uses more
non-combustible stone wool
insulation, than in Germany,
4%
which uses more polymer
insulation.9
12%
14%
Figure 4: First materials involved in building fires.8
Australian high-rise fires: construction with fiberglass Class 2, 3 and 9 buildings of two
Lacrosse (2014) and Neo batts (ca 9kg/m3) as cavity wall or more storeys, and Class 4,
200 (2019) insulation (Figure 5). 5, 6, 7 and 8 buildings of three
storeys or more. These changes
The Metropolitan Fire and
The common denominator in the did not impact residential Class 1
Emergency Services Board
Lacrosse and Neo 200 building and 10 buildings.12
(MFB) subsequently tested the
fires was the use of ACP with a ACP under AS1530.1:1994 –
100 per cent polyethylene core. 3mm PE filler
Combustibility Test for Materials
In the case of Lacrosse, the and found it was “combustible”
Light weight steel stud and batons construction
fire was started by a cigarette and therefore a product that
butt on the balcony, which is not compliant under the
Two layers of
then spread and raced up the Australian building codes.11 plasterboard
(2x13mm)
building’s ACP cladding.10
Outside of building
As a result of the investigations
The Lacrosse general into the Grenfell, Lacrosse
construction was suspended and Neo 200 fires, Victoria
reinforced concrete floor slabs banned the use of ACP with a
and reinforced concrete load core of more than 30 per cent
bearing walls covered with ACP. polyethylene to be used as an
external wall system.
However, the area affected by the
fire (a wall between an external Victoria also banned the use
facing bedroom and a balcony), of expanded polystyrene (EPS)
products used in a rendered 0.5mm thick aluminium sheet
had ACP directly attached
to a lightweight steel frame external wall system for all Type A Figure 5: Schematic of Lacrosse
or Type B construction including building wall construction.
3Fire prevention to reduce fatalities
Fire prevention is a complex approximately half of fire-related The BIO is a comprehensive
subject involving many factors fatalities in Melbourne from 2004– proposed regulatory framework
such as building design, 2005 occurred in houses without for fire safe buildings which starts
construction, services working smoke alarms – despite with prevention (refer to the MBA
maintenance (e.g. gas and smoke alarms being mandatory for more information).
electrical appliances), strict under the Building Code of
In addition, Australia should
enforcement of laws that govern Australia (BCA) since 1996.14
note that following the Grenfell
fire prevention and social issues
AMBA fully supports the work tragedy, the EU established
related to fire risks.
of the Modern Building Alliance the Fire Information Exchange
Building design includes passive (MBA) in promoting the seven Platform (FIEP) to facilitate
and active fire prevention systems layers of fire safety in buildings15 the exchange of fire safety
(e.g. sprinklers and smoke and the building, installation and information and best practice
alarms, means of escape, organisational (BIO) regulatory among member states.16
compartmentation). Provisions framework to ensure that national
Such a platform is missing in
for early warning of fires are building codes and product
Australia and further fire policy
essential. standards work together in the
decisions are currently being
EU to address all relevant factors
For example, while there is inhibited by the absence of more
in relation to the prevention of
limited data for Australia,13 granular data related to fires in
building fires.
Australian buildings.Large-scale fire testing The role of product specification
The compliance and fire safety Following the Lacrosse and Neo 200 fires, it has become
of building systems is governed clear that architects need to take the time to research the
by the NCC 2019. This requires products they specify and ensure these comply with the BCA.
approved construction materials
In the case of the Lacrosse fire, the architect had recently
that have been installed correctly
had an appeal rejected after it was found liable for damages
and maintained in accordance
caused by its specification of an ACP with a 100 per cent
with manufacturer guidelines
polyethylene core that did not comply with the BCA.17
and all related building and
construction codes and In her analysis of that failed appeal, Bronwyn Weir
standards. summarised that the decision “confirms that courts will
expect architects to prepare documents that demonstrate
The fire performance of a facade
BCA compliance. The involvement of other specialist
system cannot be predicted
consultants does not relieve the architect from its obligation
purely based on small-scale fire
to understand and apply the BCA to its design.”18
tests such as combustibility of
individual components. Rather, If an architect is looking to specify insulation, it needs to be
it depends on the interaction of all tested in accordance with AS 4859.1:2018. Similarly, if the
components within a system. insulation is to be used as part of an insulated rainscreen
system, that system should be tested to AS 5113:2016 –
For this reason, AMBA supports
regardless of the combustibility of individual components
the focus of the NCC 2019 on
– and the applicability of the test results in terms of allowed
performance-based solutions
variations in thickness must be unambiguous.
and large-scale fire testing of
facades in line with AS 5113: All facade system components must also be clearly identified
Fire Propagation Testing and – especially cavity barriers, which are essential in ventilated
Certification of External Walls facade systems (there were no cavity barriers installed on
of Buildings and Verification the Lacrosse or Neo 200 buildings, with many cavity barriers
Method CV3. incorrectly installed on the Grenfell Tower).
This test requires the large-scale Finally, to eliminate variations in formulations and test
evaluation of the fire performance conditions, and ensure accurate and compliant results,
of the full facade system including all individual product fire tests should be conducted locally,
the rainscreen, insulation and rather than offshore by individual companies.
cavity barriers.
Safety is our priority
PIR insulation boards do not
AMBA’s priority is to foster a safe built environment for
melt or drip when exposed
Australians – ensuring our buildings are designed and
to heat and can achieve an constructed to protect the people that construct, live and
EW classification under AS work in them.
5113:2016 when tested with
We are committed to working with industry, government,
a non-combustible cladding authorities and fire safety professionals to share knowledge
in a full facade system with and best practice in further advancing the safety of Australian
cavity barriers. buildings.
5More information:
www.australianmodernbuildingalliance.org.au
References
¹ 75mm Rockwool Rainscreen Duo 7
Bryant, S. and Preston, I. (2017). Coates, L. et al. (2019). Preventable
13
Slab. Retrieved 26 April 2021 from Focus on trends in fires and fire-related residential fire fatalities in Australia: July
https://www.insulationshop.co/75mm_ fatalities. UK Home Office. Retrieved 22 2003 to June 2017. Bushfire and Natural
rockwool_rainscreen_duo_slab.html April 2021 from https://assets.publishing. Hazards CRC. East Melbourne, VIC.
service.gov.uk/government/uploads/ Retrieved 26 April 2021 from https://
² Moore-Bick, M. (2019). Grenfell Tower
system/uploads/attachment_data/ www.bnhcrc.com.au/sites/default/files/
Inquiry: Phase 1 Report. Grenfell Tower
file/650869/focus-trends-fires-fatalities- managed/downloads/preventable_
Inquiry. Retrieved 26 April 2021 from
oct17.pdf residential_fire_fatalities_july_2003_
https://www.grenfelltowerinquiry.org.uk/
to_june_2017_bushfire_and_natural_
phase-1-report 8
Kobes, M. and Groenewegen, K. (2009).
hazards_crc.pdf
Consumer fire safety: European statistics
³ Marshall, J. (2018). Grenfell was not
and potential fire safety measures – Senate Legal and Constitutional Affairs
14
designed to provide a safe escape route,
Version 3. Nederlands Instituut Fysieke Committee secretariat. (2015). Use of
say fire services. Retrieved 26 April
Veiligheid. Arnhem, Netherlands. smoke alarms to prevent smoke and
2021 from https://www.building.co.uk/
fire related deaths. Department of the
news/grenfell-was-not-designed-to- 9
Modern Building Alliance. (2021).
Senate, Parliament House, Canberra.
provide-a-safe-escape-route-say-fire- Fire Safety Statistics. Retrieved
services/5093975.article 26 April 2021 from https://www. Modern Building Alliance. (2021). EU Fire
15
modernbuildingalliance.eu/fire-safety- Information Exchange program (FIEP).
4
Gayle, D. (2018). Grenfell survivors tell
statistics/ Retrieved 22 April 2021from https://
how they ignored advice to ‘stay put’.
www.modernbuildingalliance.eu/EU-fire-
Retrieved 26 April 2021 from https:// 10
Victorian Cladding Taskforce. (November,
safety-guide
www.theguardian.com/uk-news/2018/ 2017). Victorian Cladding Taskforce –
oct/04/grenfell-tower-survivors-tell-how- Interim Report. The State of Victoria Modern Building Alliance. (2021). EU
16
they-ignored-advice-to-stay-put Department of Environment, Land, Fire Safety Guide – The 7 Layers of
Water and Planning. Retrieved 26 April Fire Safety in Buildings. Retrieved
5
Raffaelli, F. (2018). Report on
2021 from https://www.planning.vic.gov. 22 April 2021 from https://www.
FIEP Progress – Update from DG
au/__data/assets/pdf_file/0012/110316/ modernbuildingalliance.eu/eu-fire-
Grow.C.1. European Commission.
Victorian-Cladding-Taskforce-Interim- information-exchange-platform/
Retrieved 26 April 2021 from https://
Report-November-2017.pdf
www.modernbuildingalliance.eu/ Cheng, L. (2021). Architect and other
17
assets/uploads/2018/11/DG-Grow_ 11
Badrock, G. (2016). Post incident consultants lose appeal in cladding
presentation.pdf analysis report: Lacrosse Docklands, 25 fire case. Retrieved 22 April 2021 from
November 2014. Metropolitan Fire and https://architectureau.com/articles/
6
CIBSE Journal. (November, 2018).
Emergency Services Board, Melbourne, Lacrosse-appeal/
Technical note: the government ban
Australia.
on combustible materials in high-rise Weir, B. (2021). Room for (in)novation:
18
residential buildings. Retrieved 26 April 12
State Government of Victoria. (2021). Responsibilities of and liabilities for
2021 from https://www.cibsejournal. Banning dangerous cladding and architects. Retrieved 22 April 2021 from
com/technical/technical-note-the- keeping Victorians safe. Retrieved 22 https://architectureau.com/articles/
government-ban-on-combustible- April 2021 from https://www.vic.gov. responsibilities-of-and-liabilities-for-
materials-in-high-rise-residential- au/banning-dangerous-cladding-and- architects/
buildings/ keeping-victorians-safe
Disclaimer: This publication contains information of a general nature only, is provided as an information service, and is to the best of our knowledge,
true and accurate. It is not intended to be relied upon as, or a substitute for specific professional advice having regard to your specific circumstances.
Any recommendation or suggestions which may be made are without warranty or guarantee, since the conditions of use and the composition of source
materials are beyond our control. It should not be construed as a recommendation to use any product in conflict with existing patents covering any material
or its use. No responsibility can be accepted by Chemistry Australia Ltd, AMBA (Australian Modern Building Alliance) or the authors for loss occasioned
to any person doing anything or not doing anything as a result of any material in this publication.
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