polystyrene and fire safetyRecent
tests have confirmed the fire retardant properties
of StyFRene expanded polystyrene (EPS) FR grade thermal
insulating board. The key finding of the tests
is that, in a fire, EPS does not support the spread
Architects and specifiers can now confidently incorporate
EPS in designing energy-efficient and cost-effective
building solutions, by using StyFRene.
The tests, commissioned by EPSASA, were conducted
by Firelab cc, based on the premises of the Council
for Scientific and Industrial Research (CSIR) in Pretoria.
They were carried out in line with the protocol defined
in SANS 428:2006 – “Fire performance classification
of thermal insulated building envelope systems”.
SANS 428 covers the fire safety evaluation requirements
for thermal insulated building envelopes, such as
under-roof and side-cladding insulating materials,
liners, insulated wall and roof panels, insulated
ceilings and insulated wall and ceiling coating systems.
This testing protocol requires that large-scale fire
testing of thermal insulation materials (SANS 10177:11)
must be done in a facility that simulates the real-world,
end-use conditions in which the product is typically
EPS StyFRene boards of 80mm thickness, and without
any facing material, were used in all the tests.
EPSASA generally recommends 80mm to 100mm EPS board
for ceiling and roof applications, depending on relevant
climatic conditions. Continuous improvements
in FR grade EPS, in the polystyrene raw material,
and fire retardant properties and processing, have
now produced a material that is classified as fire
The Firelab assessment entailed a series of three
tests to evaluate the material’s fire propagation
properties in different applications: under-roof without
a sprinkler extinguishing system; under-roof with
a fixed sprinkler system using slow response sprinkler
heads; and in vertical side-cladding applications.
The test results show that although EPS StyFRene does
deform and melt in proximity to fire, it does not
actually catch alight: the material simply disintegrates
into small snowflake-like fragments.
The test report concludes that: “From a fire
safety point of view, the FR grade EPS thermal insulation
system, as tested under specific test conditions,
may be used as part of the thermal insulated building
envelope in all industrial and commercial buildings
as an under-roof and side-cladding insulation material,
both with or without sprinklers.”
It is nonetheless important to note that these test
results do not relate to fire resistance, which entails
different testing criteria and testing methods.
Furthermore, factors such as adequate roof ventilation
and/or sprinkler protection should be considered in
individual installations, taking account of the specific
wall and roof configurations, to ensure the fire-safe
design of any building, according to SANS 10400:T.Suppliers
should be asked to verify their products’ conformity
to the test materials.