Fire doors can not prevent fires. The main purpose of fire doors is to localize the place of fire, i.e. not to let the fire spread to other rooms.
They are classified according to how long they can withstand temperatures less than 180 degrees on the non-flammable side. This time is measured in minutes from the beginning of the exposure of the door to fire until any of the limiting conditions (structural failure, loss of integrity and thermal insulating qualities) are reached.
The fire resistance rating of the door is indicated by a Latin letter corresponding to one of the limiting states and numerals showing the time in minutes until that limiting state is reached.
Thus, to understand what the expression fire doors ei 60, you need to familiarize yourself with the list of limiting states of the doors for fire resistance and their corresponding Latin letters:
R — loss of load-bearing capacity of the structure due to collapse or the occurrence of limiting deformations;
E — loss of integrity due to the formation of through cracks in the door, through which flames and combustion products begin to penetrate to the non-flammable surface;
I — Loss of thermal insulating capacity because the side not facing the fire is heated up to extreme values.
So, if a door has an EI 60 fire resistance rating, it means that it can withstand flames for 60 minutes without getting too hot or losing its integrity. That is, for an hour the fire will not be able to get through such a door.
Such doors are installed in offices, warehouses and factory buildings. There are fire doors that can withstand a longer period of contact with fire, but they are usually installed in special cases in special buildings. The EI 60 doors consist of two galvanized steel sheets with a minimum thickness of 0.8 mm, with a layer of mineral wool in between. In other cases, a sophisticated thermal package is used to protect against fire. Door leaf thickness up to 63 mm. Fire doors are made without a threshold.
Fireproof doors are a reliable way to keep the dwelling or office rooms from fire and minimize negative consequences in case of fire.