Understand fire resistant & Resistant to Fire

Choosing the Right Fire Retardant ACP for Façade / Cladding Applications:

Fire protection for buildings begins at the planning stage. Minimizing fire risk, particularly in places with significant human traffic such as major sporting arenas, mass transit terminals, hospitals, schools and high rise buildings has become increasingly complex and challenging. Limitation of the height of the Fire Engine to reach the higher floors is a critical point of consideration in façade design.

fire resistant construction
fire resistant construction

Of Late, in India, many high rise buildings have started insisting on Fire Retardant materials to be used in the Façade of the buildings. But, still, there is lot of ambiguity in choosing the right materials due to consideration of inappropriate / inadequate information while procuring these materials. Irrespective of the regulations, it is imperative for the users to choose the right grade of building materials which can minimize the damage to human lives and structure.

A lot depends on using the right kind of products and systems and utmost care has to be taken in choosing the right grade of Fire Retardant (FR) material so as to mitigate the risk caused by Fire. If FR is prescribed, the correct performance level of fire-retardancy is required: “true” FR materials must be demonstrated by passing challenging system tests with a multi-story setup.

Fire Resistance of Material – ACP Core:

It is very important to understand the difference between ‘Fire Resistance’ and ‘Reaction-to-Fire’. Even a normal paper is Fire Rated, but up to what level? Will this be acceptable? Answer is NO.

‘Reaction-to-Fire’ is more relevant to the materials. It deals with combustibility, ignitability, flame spread, smoke development, burning droplets & toxicity. Since we are discussing about ACP, which is Façade Material, ‘Reaction-to-Fire’ is appropriate term for selection of ACP and not Fire Resistance. Fire resistance deals with compartmentalization abilities of building systems like walls, doors, ceiling etc.

Hence, Fire Rated / Fire Resistant / 2 hour Fire rating terminology is not relevant for ACP. The appropriate terminology is “Fire Retardant ACP”.

Understanding the Performance Criteria of ACP with various test methodologies:


So an ideal Fire Retardant ACP must pass EN 13501-1 along with either NFPA 285 or BS 8414-1.

Coming to ACP Core, a true Fire Retardant ACP should have:

So an ideal Fire Retardant ACP must pass EN 13501-1 along with either NFPA 285 or BS 8414-1.

  • Ideally recommended mix and density of non-combustible content in the core is 70%
  • Core must be self-extinguishing so that if the source of fire is put off then the core should not be a medium for propagation of fire

Apart from the above, ACP with non-combustible core (mineral filler of more than 90%) is also available which can be considered for very tall buildings / places with very high human density. This product conforms to A2 as per EN 1305-1.

In either of the above mentioned ACP, a third party certification like ‘Class 1A’ from an agency of repute for the manufacturer of ACP will provide peace of mind. Certification process of ‘Class 1A’ is

  • The manufacturers facilities and production process is continuously inspected and checked by an accredited 3rd party,
  • Such inspections involved random selection and marking of future test samples,
  • Testing of such samples in accredited testing laboratories.

Majority of human loss in case of fire accident in a building is due to smoke & toxicity but not necessarily only due to Fire.

As mentioned earlier, ‘Reaction-to-Fire’ of Façade materials is very important to contain the propagation of Fire and also to carry out rescue operations. Combustibility, Ignitability, Flame Spread & Burning Droplets are the important parameters to be considered to address the propagation of Fire. However, Smoke Development & Toxicity are the key parameters for the safety of occupants and for rescue operations by Fire Brigade.

What defines performance for a fire retardant cladding solution?

Extent of lateral & vertical fire spread

Extent of smoke emissions

Extent of droplets emissions

Self-extinction of the fire on the panel

Applicable to all elements of the system used

As regards to ACP cladding is concerned it is advised to have the systems without sealants.

Information from Alucobond

(Mr. P.V. Somusundaram & Mr. Nikhil Joshi)