What is the NRO class?
NRO (Non-Fire-Propagating) is a term used in construction to assess the behavior of building products and elements during the initial phase of a fire.
In practice, the NRO classification allows determining whether a given structural element will not contribute to the rapid spread of flames across its surface.
However, it is worth remembering that the NRO designation does not mean the material is completely non-combustible.
This is one of the most frequently misinterpreted terms related to fire protection.
What does fire classification test?
During fire testing, among other things, the following are analyzed:
- reaction of the material to fire,
- flame spread rate,
- amount of smoke produced,
- formation of burning droplets,
- behavior of the product during the initial phase of a fire.
These tests are carried out by accredited research institutions, such as the Building Research Institute. Through which our products are certified.
NRO and fire reaction class - what is the difference?
These are two different concepts.
NRO Class
Determines the behavior of the product in terms of fire spread.
Fire reaction class
Determines how a material behaves when in contact with fire.
The following classes are used:
A1 - non-combustible material
A2 - very limited contribution to fire
B - very limited contribution to fire
C - limited contribution to fire
D - medium contribution to fire
E - highly flammable
F - no classification
What do the symbols s and d mean?
Fire reaction classes are supplemented with additional markings.
Symbol "s"
Determines the amount of smoke emitted.
- s1 – least smoke
- s2 – medium amount of smoke
- s3 – most smoke
Symbol „d”
Indicates the occurrence of burning droplets or particles.
- d0 – no burning droplets
- d1 – limited occurrence
- d2 – intense occurrence
What fire reaction class can terrace pedestals have?
Standard terrace pedestals are most often made of polypropylene, and therefore have class E.
Depending on the flame retardant additives used, it is possible to achieve higher fire reaction classes.
For projects with specific fire protection requirements, pedestals with the following classification are used:
B-s3-d0
This means:
- fire reaction class B,
- smoke emission at level s3,
- no burning droplets (d0).
It is one of the most frequently required classes when specialist applications in commercial construction are necessary.
Terrace pedestals NRO from SOLVER
On special order, pedestals with the following classification are available:
B-s3-d0
The classification was developed based on tests conducted by the Building Research Institute (ITB).
These pedestals are intended for projects where the design requires the use of elements meeting specific fire safety requirements.
When is it worth using NRO pedestals?
Pedestals with enhanced fire performance parameters are most often used in the construction of:
- hotels,
- office buildings,
- public utility buildings,
- commercial terraces.
The final selection of the class should always result from the building design and the requirements of the designer responsible for the fire protection of the building.
Summary
Class NRO does not mean that the material is completely non-combustible. It means, however, that under specific conditions it does not contribute to the rapid spread of fire.
In the case of terrace pedestals, the fire reaction class is also particularly important. For projects with elevated fire safety requirements, SOLVER pedestals are available in the class:
B-s3-d0
If the project requires the use of NRO pedestals or pedestals with a specific fire reaction class, it is worth considering this requirement already at the stage of preparing the offer and selecting the raised deck terrace system.
