class b fire doors are enough! \x1d\ Article 7.2.3 of the Building Regulations: \x1d\ The partition walls of the following buildings or parts shall be incombustible with a fire resistance limit of not less than 2.11h, and the doors and windows on the partition walls shall be Class B fire doors and windows: \x1d\1 Class A and Class B workshops and workshops using Class C liquid; \x1d\2 workshops with open flames and high temperatures; \x1d\3 Auxiliary rooms in the backstage of the theater; \x1d\4 The foyer of the first-class and second-class fire-resistant buildings; \x1d\5 kitchens in buildings other than houses; \x1d\6 Rooms with different fire hazards are arranged in Class A, B and C workshops or Class A, B and C warehouses.