Sets 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.
It applies to products and building elements for which a fire-resistance requirement is prescribed for fire-safety purposes. 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. The European basis of that classification has moved, however: since 3 July 2024 the performance classes of construction products are set by Delegated Regulation (EU) 2024/1681, which repealed Decision 2000/367/EC.
While 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.
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 |
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.
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.
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.
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.