Although it is only a small component, the locks and latches on a fire door need to be correctly specified so that the door latch can keep the door closed with the frame. If the latch cannot hold its integrity during a fire, there is risk that the door will become unsecure and will allow fire and smoke to travel through to the next room. Latches need to have a high melting point so that they can hold the door in place.
Locks and latches are tested by the manufacturers and are given an 11 digit code. This provides the necessary information on: the durability of the product, whether it is fire rated, door mass and closing force, and corrosion and temperature resistance.
Locks and latches need to be installed correctly so that it does not reduce the fire performance of the door. This is because installing these items requires the need to cut in to the door. The cut out within the fire door must be kept to an absolute minimum so that a tight seal is created. Without this, fire and smoke can penetrate through the fire door.
The standard covering locks and latches is BS EN 12209. Locks and latches should be CE marked and fire tested to BS EN 1634-1 / 1634-2. Other standards to take in to consideration are BS EN 179 and 1125 which focus on emergency exit devices.