Projects
Find out what projects we have been involved in
Fire Protection
How to protect your property from fire
Videos
See intumescents in action in the FIRETEX video
What is an intumescent coating?
An intumescent coating is a specialist paint that chemically reacts in a fire. The
coating swells in size to form a char, which protects the steelwork for a specified
period. As the intumescent doesn’t actively tackle a blaze it is known as passive
fire protection.
Steel is a very strong and versatile building material, but at temperatures of 550ºC
it begins to loose its structural integrity, which may lead to building collapse.
The role of fire protective coatings is to lengthen the time taken for the steel
to reach its critical failure temperature and therefore allow occupants sufficient
time to escape and enhancing the safety of the rescue services.
Depending on the type of structure and its occupancy a fire rating is awarded i.e.
a length of time which a structure must remain structurally sound in a fire situation.
There are a range of solutions available from active fire protection like sprinklers,
as well as passive fire protection like intumescents.
How does it work?
Intumescent coatings are normally applied by airless spray to provide a smooth decorative
finish, which remains stable at ambient temperatures. These coating compositions
are based on organic resin binders, which are typically acrylated rubber or epoxy.
The resins are filled with active ingredients, which react in a fire at temperatures
around 250°C to form a thermally insulating carbonaceous char or foam. The char
can be expanded up to 50 times the original coating thickness.
The char reduces the rate of heating of the steel and hence prolongs its load bearing
capacity.
As described above the basic formulation of an intumescent comprises of an organic
binder, a carbonific, usually a penta or dipentaerythritol, a spumific or blowing
agent which could be melamine or a melamine formaldehyde derivative, a source of
an acid catalyst such as ammonium polyphosphate and additionally a char reinforcing
pigment.
As the temperature rises the binder begins to melt and the blowing agent liberates
gases causing a controlled expansion. At the same time there is degradation of the
carbon backbone and fusion of the inorganic reinforcing materials, resulting in
char solidification.
Advantages of intumescent coating…
Steel is frequently specified, as it offers maximum design flexibility. Alternative
construction materials such as concrete can lead to slower erection sequences and
heavier foundations
In addition, off-site coating in steel workshops actually reduces time on the critical
path by at least 2 weeks. This in turn provides substantial financial savings as
well as delivering a finished building to the client early.
In this age of steel and glass commercial buildings, exposed steelwork has become
an integral design feature. Intumescent coatings allow steel to be used as an architectural
feature (where fire protection boards would not) while also conforming to building
regulations.
Intumescent coatings provide steel structures with corrosion protection, fire protection
and a strong decorative element if required.
Special circumstances – hydrocarbon fires
Hydrocarbon fires show a very rapid rate of heating combined with extreme turbulence
and result from the burning of hydrocarbon based fuels such as oil and gas. Therefore
a specialist fire protection measure is required. Specialist intumescent coating
have been developed to cope with the demanding nature of hydrocarbon fires, where
resistance to blast overpressure and jet fire is a strong probability.
Oil and gas projects exist in some of the most aggressive environmental conditions
and require not only fire protection but also exceptionally durable coatings. Epoxy
intumescents are able to provide not only the fire protection requirements, but
also blast resistance and extreme durability to the worst weather conditions.
Back to Technical Information