Fire-resistance classification of construction products and elements
Summary
TAV. 00Sets the fire-resistance classification criteria - load-bearing capacity (R), integrity (E), insulation (I) and combinations RE, REI, REI-M - for construction products and elements, and the three permitted methods to determine it: testing, tabular and analytical.
Scope of application
TAV. 01Applies to products and construction elements for which a fire-resistance requirement is prescribed for safety in case of fire. It transposes the European classification (EN 13501-2) and works together with the Fire Prevention Code (D.M. 03/08/2015), which sets when and which class is required.
In depth
TAV. AWhile reaction to fire describes how much a material feeds a fire, fire resistance describes something different and complementary: how long a construction element keeps doing its job while the fire is burning. This decree provides the Italian framework for classifying it, in line with the European standard EN 13501-2.
Three letters, three performances: R, E, I
Classification rests on three criteria, which can appear alone or combined. The resulting symbol (e.g. REI) says which performances the element guarantees; the number that follows says for how many minutes.
| Criterion | Meaning | Guarantees that... |
|---|---|---|
| R | Resistance (load-bearing capacity) | the element does not collapse under load during the fire |
| E | Integrity (seal) | it does not let flames and hot gases pass from the exposed side |
| I | Insulation | it limits the temperature rise on the unexposed side |
How the class is determined: three routes
- 01ExperimentalFire-resistance tests on a specimen in the laboratory, according to the European test standards.
- 02TabularAssigning the class via the tables annexed to the decree, based on the element's dimensions and characteristics.
- 03AnalyticalCalculating resistance with engineering methods (the fire parts of the Eurocodes), accounting for connections and interactions.
Key points
TAV. K- Classes R / RE / REI / REI-M with time in minutes (e.g. REI 120)
- Three permitted methods: testing, tabular, analytical (fire parts of the Eurocodes)
- Coordinated with the test methods of UNI EN 13501-2
Materials concerned
TAV. MProcesses involved
TAV. PFrequently asked questions
TAV. QWhat does REI 90 mean?
An element that guarantees, for 90 minutes of fire, load-bearing capacity (R), integrity against flames and hot gases (E) and thermal insulation (I) at the same time.
What is the difference between R, RE and REI?
They are increasing combinations of criteria: R is load-bearing only (e.g. a column); RE adds integrity; REI adds thermal insulation too (typical of a compartmenting wall). The required combination depends on the element's role.
Which method should I use to determine the class?
One of three: experimental (lab test), tabular (tables annexed to the decree) or analytical (engineering calculation per the fire parts of the Eurocodes). The choice depends on the element and on available data.
What does the M add in the REI-M symbol?
The M indicates resistance to mechanical action: the element keeps its performance even under an impact (for instance the collapse of another element during the fire). It is added to the class when that action is relevant.
Glossary
TAV. G- R — Resistenza
- Load-bearing capacity: the element keeps carrying its load during the fire.
- E — Ermeticità
- Integrity: the element prevents the passage of flames and hot gases.
- I — Isolamento
- Insulation: the element limits the temperature rise on the unexposed side.
- Compartimentazione
- Dividing a building into volumes that confine fire and smoke for a set time.
- M — Azione meccanica
- An additional criterion (REI-M) attesting the element's resistance to a mechanical action, such as a shock or impact, during the fire.