By “protected volume” we mean a room or a cupboard whose volume is protected from external fire so that any materials it contains can continue to provide their services for a certain time.
As a general rule, this time should correspond to the degree of fire stability required for the building, with a maximum of one hour, except for the passage through rooms at particular risk, for which the protection must be identical to the requirements for those rooms.
Made using staff, aerated concrete or cellular limestone slabs, it can have a door, a trapdoor and ventilation aperture, providing a technical volume that is fire resistant for up to two hours.
