June 2020

Aluminium cladding
NOT AS EASY AS ABC...…
Contractors need to pay more attention when it comes to aluminium cladding specification
on tall buildings, says Gillian Thomson, General Manager of MSP (Scotland).
Understandably, those involved in the
construction of high-rise buildings have
gone for a ‘belt and braces’ approach
when it comes to aluminium cladding
specification. And given the catastrophic events
at Grenfell Tower in 2017, it’s little wonder that
everyone in the supply chain, including architects,
surveyors, contractors and installers, are erring on
the side of caution when it comes to the choice of
new or replacement façade systems.
However, notwithstanding the critical nature of
cladding specification, has the industry got itself
into a situation where a basic misunderstanding
of the Euroclass fire rating standard is causing
confusion, added cost and quality issues, without
any real improvement in safety? Certainly, when
it comes to the use of PPC (powder coated) and
PVdF (pre-coated) aluminium sheeting, there are
signs that over-specification is becoming a trend
within the building industry. Crucially, it is the
introduction of A1 and A2 categories that has
caused much of the confusion.
Fire safety ratings
It is now well known that all cladding used on
buildings of over 18 metres tall should be noncombustible
– thus the material should conform
to an A class performance rating under EU safety
regulations. Following an announcement by
housing minister Robert Jenrick in January this
year, any residential building over 11m could
soon need to use non-combustible cladding.
Specifically, the standards relevant to aluminium
façades and fire safety are EN13501 and EU
Directive 96/603/EC.
In the wake of Grenfell, the demand for solid
aluminium cladding has increased markedly –
mainly due to its A rated, non-combustible
“While this focus on a material’s ability to
suppress fire, smoke and fumes is a welcomed
step, this also requires an improved level of
technical understanding among specifiers and
contractors alike”
Gillian Thompson, General Manager of MSP (Scotland).
nature. While there are at least 450 ACM-fitted
towers in England needing remediation work, the
figure for all high rise buildings requiring
recladding across the UK is at least three times
this figure.
Devil in the detail
The problems occur when you look deeper into
the details of the Euroclass Fire Classification
System, which runs from A through to F. While A
rated (the best) materials make no contribution to
fire, create insignificant smoke with no flaming
droplets or particles, an F rating (the worst)
indicates that the tested materials are easily
flammable and may create copious amounts of
smoke, toxic fumes and encourage the spread of
fire. This system is clear so far, however
confusion has been created by the division of the
A rating into A1 and A2 – both of which are
completely safe and appropriate for use on highrise
projects.
In practice, both A1 and A2 classifications are
more than adequate for projects of over 18
metres (soon to be 11m) in height. The trouble is
that too many specifiers and contractors have not
taken the trouble to read and fully understand the
Euroclass regulations and so are not confident
about interpreting and following the regulations.
In practice, this can lead to a form of Chinese
whispers along the supply chain.
Typically the developer, who is now
42 TC JUNE 2020