Fire doors (hatch, gate) should prevent the spread of fire to adjacent rooms during some normalized period of time. This time interval is usually from 30 minutes to one and a half hours.
The airtightness of the doors also prevents smoke from spreading to adjacent rooms, which is confirmed by a smoke-tightness certificate. All this can not only localize the fire, but also reduce the possible damage to property and greatly facilitate the extinguishing of the fire.
