Built-in protection

Non-combustible and fire retardant explained

The terms “non-combustible” and “fire retardant” are often confused. There is, however, an extremely important difference. If something is non-combustible it will not burn under real-world conditions. It’s a simple, unambiguous quality. Fire-retardant materials, on the other hand, will contribute to a fire once the chemicals added to inhibit ignition have been overcome. The degree to which something is fire retardant is harder to quantify. 

This is why non-combustibility is a core feature of fire regulations around the world, and a crucial element of building safety in the case of fire. Whatever the fire source, temperature or air supply, building materials or elements that are non-combustible will remain largely resilient to fire. As far as fire regulations are concerned, non-combustibles can be used to an unlimited extent in any building application.

Fire retardant

“Fire retardant” materials, on the other hand, are combustible. There is no global standard on how to measure the degree to which a combustible product contributes to the spread and growth of a fire, although ways to measure this include:

• How easily the product is ignited
• The amount of heat released when it burns
• How fire spreads on its surface
• The way in which it disintegrates as it burns
• The quantity and nature of smoke released

A critical role 

Because of these different parameters, rating schemes for combustible products are complex, and their fire performance characteristics are often described in relation to testing conditions. Performance ratings may also differ if a product is used standalone or as part of a composite structure. For example, while a rating for “end use conditions” describes how fire-retardant insulation performs behind a protective layer, it is the top layer of the construction that has the most significant impact on the test result, not the core of the composite being tested.

Non-combustible materials have a critical role to play in keeping modern buildings safe. ROCKWOOL advocates that all mid- and high- rise, sensitive and high occupancy buildings (such as hospitals and care homes, schools, hotels and sports arenas, where there may be challenges in exiting the premises regardless of their height) should only be clad and insulated with non-combustible materials.