Along with fire curtains, fire doors are a form of passive protection; they help to limit the damage that a fire causes by preventing the flames from spreading. However, unlike fire curtains and smoke curtains, many doors do not automatically close when a blaze has been detected. The only time a fire door will close automatically is when it has been fitted with a specialist retainer.
Types of Fire-Door Retainer
There are various different types of retainers available which allow fire doors to be kept open legally, when the circumstances require it; this could be for ventilation purposes, or simply because a large amount of traffic passes through on a regular basis. By fitting such a retainer, businesses can be assured of complying with fire safety law.
Magnetic retainers are ideal for use in conjunction with panel alarm systems; whereby an electro-magnetic plate is fitted to the wall to hold the door open on a permanent basis. If the alarm is activated, a signal is sent to the plate and the door will close. If the premises are fitted with fire curtains, these will also automatically come down, and therefore compartmentalising the fire in a manageable area.
Overhead fire-door retainers are commonly found in places such as hospitals and schools. They work in a similar fashion to the magnetic variety, but are usually installed when the building is initially constructed. The third type of retainer is battery-operated, activated by the sound of a fire alarm rather than an electric signal. The main advantage with this type of retainer is that it can hold the fire door open in a variety of positions to suit the circumstances.
If it is absolutely essential for your fire doors to remain open legally, by making sure they are fitted with an approved retainer; otherwise you will be breaking the law and could be putting lives at risk.
