NFPA Journal - May/June 2020 - 55

insulating composite systems-both of
which consist of a layer of insulation,
a reinforced mesh layer, and a thin
coating of exterior material-as well
as the ventilated façade system, where
an air gap of at least 1 inch between
the insulation and the covering panels
allows moisture to escape. The insulation used in these systems can be
combustible (such as polystyrene or
polyurethane) or noncombustible (such
as mineral wool or foam glass)-but the
price, weight, and thermal performance
makes combustible insulation the
preferred option in most applications.
This choice comes with the inherent
challenge of ensuring that it does not
become involved in a fire. The covering
used in ventilated façades also comes
in many versions, from inert natural
stone to metal composite panels with
combustible cores-again, spanning
a vast range of potential risk in the
event of fire. The ease with which these
systems ignite and spread fire depends
on the combustibility of the materials
used and how the system is designed to
limit ignition and fire spread, such as

through the use of fire breaks and other
protective measures.
An important aspect that is often
overlooked is the quality of the installation of these systems. When using
combustible materials, it is critical to
ensure that they are protected from
ignition and that added protective
measures such as fire stopping and
barriers are installed correctly. Many
installers are often unaware of how
minor details can have major impacts
on the performance of finished systems
when exposed to fire. A highly skilled
workforce is essential if we hope to
ensure the safety of these complex
façade systems.

BUILDING REGULATIONS AND
TEST METHODS
In an effort to prevent external fire
spread, most building codes and regulations incorporate requirements
addressing the fire performance of
exterior walls. Controlling external
fire spread is done through requirements applied to the facade systems.
While the safety objectives of these

TAKSIM ILK YARDIM HOSPITAL
3.14.19
KAIFENG
APARTMENTS
Kaifeng, China
After fire broke out
on the exterior of the
high-rise tower,
winds reportedly
helped it spread from
the second floor to
the 17th floor in less
than two minutes.

5.27.19
GOLDEN EAGLE
SHOPPING MALL
Nanjing, China
Dramatic video
footage posted online
captures a large fire
rapidly ascending the
exterior of the largest
shopping mall in Asia.

requirements are similar from country
to country, the manner in which they're
carried out can be very different. As
with all fire requirements around the
world, those related to exterior façades
are based on national experience-for
example, if a catastrophic fire with
external fire spread has occurred-as
well as local building tradition.
One approach used in many countries is to apply combustibility and/
or flammability requirements to each
material used in the façade system-the
rationale being that by controlling the
performance of each component, the
combined system should reflect an
appropriate (and appropriately safe)
function. The requirements are linked
to the perceived hazard for the building
and are dependent on the height of the
building and its occupancy. A typical
example is to require the use of only
noncombustible materials if the building exceeds a certain height, which can
range from 12 to 50 meters, or 39 to 164
feet, depending on the country.
Another approach is to require testing of the entire façade system, often

ZEN TOWER
5.29.19
COMMERCIAL
BUILDING
Luoyang, China
To accompany a
social media video
of an exterior fire
coursing up the side
of a large commercial
block, one observer
tweeted, "Another big
façade fire happened
in Luoyang, China,
today...It is so
frequent."

8.14.19
RESIDENTIAL FLATS
Warsaw, Poland
Discarded smoking
materials were
suspected in starting
a garbage fire that
ignited the façade of
this 10-story residential
building, burning
from ground level
to the roof.

11.16.19
THE CUBE
Bolton, UK
Fire destroyed the
six-story apartment
block that housed
200 university
students. The building
reportedly did not
have fire-resistant
cladding because
it was six inches
below the height that
would have triggered
stricter requirements.

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NFPA Journal - May/June 2020

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