Fire Door Help & Information
The subject of fire doors can be daunting for non-professionals in the field of fire safety. In this guide, we seek to address the main issues surrounding fire doors for those responsible for the safety. We begin with a brief look at the relevant current legislation on fire safety, to set the subject in its context.
The Regulatory Reform (Fire Safety) Order 2005, which came into force in October 2006, states that the safety of people working in/visiting non-domestic premises and common areas of blocks of flats falls to the "responsible person". In summary, as noted in the HM Government publication "A short guide to making your premises safe from fire" (June 2006), the responsible person as defined by the Order is anyone who has control of the premises, or anyone who has a degree of control over certain areas or systems, for example:
- The employer for those parts of premises staff may go to;
- The managing agent or owner of let properties
- The occupier, e.g. self-employed tenants, if they have any control over the premises; or
- Any other person who has some control over a part of the premises
Depending on the circumstances, fire safety responsibility may be shared by more than one person. It is the duty of the responsible person(s) to ensure that a fire risk assessment of the premises is carried out.
The fire guidance issued by the government includes a checklist of five key steps, beginning with the identification of fire hazards and people at risk. The next step, on evaluation and action, includes the need to identify escape routes in the premises and the relevant fire safety equipment.
Fire doors are a vital component in this regard, offering protection of the escape route from fire in adjacent rooms and by compartmentalising sections of escape routes or building segments.
What is a fire door?
The Architectural and Specialist Door Manufacturers Association (ASDMA) defines a fire door as follows:
"A complete installed door assembly comprising doorframe, door leaves, other panels, hardware, seals and any glazing that when closed is intended to resist the passage of fire and smoke in accordance with specified performance criteria. A fire door = a complete installed assembly."
From this, we can understand that there is more to a fire door than meets the eye; and that, when configured, assembled and installed correctly, it will be more than the sum of its individual parts.
The parts of a fire door assembly
As indicated by the ASDMA definition above, fire door assemblies - or fire doorsets, as they are also known - comprise a number of parts and accessories.
An internal fire door leaf is typically made of solid timber. It can be plain or panelled, with a number of finishes. If glazing is required, this has to be done with fire resistant glass: the two main types are Georgian wired and clear glass (e.g. Pilkington Pyrodur®). The Safelincs fire door ordering process is a simple and cost-effective way to configure and purchase your fire door(s), including glazing in various glass types and glazing shapes.
Smoke spread is a major cause of death and injury in a fire situation; in fact, it constitutes a greater threat to people than the fire itself. As such, it is a requirement of most fire doors, in particular those whose function it is to preserve an escape route, to provide a smoke control function on top of preventing the spread of fire. In the early developing phase of a fire, this is commonly referred to as "cold smoke"; the current test method for evaluating the leakage rate of such smoke through a door assembly is BS 476: Part 31.1. The purpose of a smoke seal is to prevent the egress of cold smoke around the fire door edges and, by containing its spread, facilitate the evacuation of the building. It is important to ensure, when fitting smoke seals, that they do not hinder the full and effective closure of the door.
As a fire develops, the hot gases generated will eventually be forced through any apertures in the initial fire compartment: for example, the gap between a door and its frame. A fire door must therefore be fitted with intumescent seals, which remain dormant under normal conditions but expand greatly in volume when heated, serving to close the gap and thus contain the smoke and flames. In contributing to the integrity of a fire doorset, the relevant current test of intumescent seals is to BS 476: Part 22 or BS EN 1634-1. Depending on the specific purpose of a fire door, it may be necessary to fit both a smoke and an intumescent fire seal, either separately or as a combined unit. All of the fire door seals sold by Safelincs are combined smoke seals/intumescent seals.
All fire door hardware (locks, latches, hinges, etc.) must be to fire rated standard. A fire door must also have an automatic closing device: it has to permit the free flow of traffic during everyday use but must be able to self-close in the event of a fire.
Internal fire doors should never be propped or wedged open; as well as being hazardous, it is an illegal practice, though one that is frequently observed. To facilitate the free flow of traffic in a building without breaking the law, it is advisable to fit a door retainer. This type of device will hold a fire door open under normal circumstances but will automatically release the door in a fire situation.
A fire door must be identified as such. Internal fire doors should carry an appropriate sign: for example, when they are routinely held open by a door retainer but need to self-close readily in a fire situation, "Automatic fire door keep clear" indicates that the route must remain unobstructed. For restricted access areas that are not usually populated, such as storage cupboards and boiler rooms, and which have no self-closing device fitted, "Fire door keep locked" indicates that the door must be kept shut at all times.
Relevant legislation in respect of mandatory signage, including fire safety signs, is contained in the Health & Safety (Safety Signs and Signals) Regulations 1996.
Where are fire doors needed?
As indicated above, there are two main requirements of fire doors, which prescribe their location in a building. They work together in an integrated system in order to preserve life and property through i) compartmentalising a fire; and ii) creating/protecting an escape route through the building. For example, to protect a corridor from rooms opening on to it, or a stairwell from the corridor(s) it serves.
The escape route in a fire situation is frequently the route of everyday traffic, hence the fire doors must not impede the normal functioning of a building. As earlier noted, door retainers can be used to keep them legally open, although the doors should be regularly closed as part of their routine maintenance in order to prevent warping or other malfunctions that could compromise their integrity in a fire situation.
In serving to compartmentalise a building and/or preserve an escape route, the function of a fire door, when closed, is to provide resistance to smoke/fire for a minimum specified length of time. Typically, this is 30 minutes with a certified fire door of timber construction (FD30). It is possible to have steel fire doors offering up to 4 hours resistance but this level of protection is usually only a requirement in specific, high-risk environments. Thirty minutes should, in most situations, allow for the evacuation of premises and response of the emergency fire services.
Can existing doors be upgraded to fire resistant standard?
Due to the specialist nature of fire doors, it is always advisable to fit them from new. This is often the most cost-effective option as well.
An upgrade to FD30 status is sometimes possible, however, depending on the construction of the existing door, especially if it is part of an historic building. It should be of solid timber or chipboard, at least 44mm thick, and with a sound frame that is capable of bearing the additional weight of the upgraded door. The gap between the door and the frame should be 2 to 4mm.
An unpainted door can be coated with intumescent varnish or paint, to manufacturer/supplier specifications. A painted door can be covered with an intumescent membrane with fireproof card/wood veneer facing, which is more aesthetically pleasing than plain, non-combustible board. If glazed, the glass panel(s) must be replaced with fire rated glass.
The upgraded door must be re-hung with at least three fire protected hinges, to prevent warping. The integrity of a fire door will be severely compromised if it should warp, as it will no longer fit snugly in its frame. All other hardware, e.g. locks, latches, etc, must be similarly upgraded to fire resistant standard. Other modifications, including the addition of intumescent seals, will also be necessary, as indicated in the section above concerning the various parts of a fire door assembly. Some surface mounted fire door seals allow an upgrade without having to cut out a channel in the door to fit the seals.
Certification of a fire door
Manufacturers of "off the peg" or bespoke/customized fire doors can have their products 3rd-party certified, thereby guaranteeing the level of fire resistance. The standard test of a fire doorset is to BS 476 Pt 22 or BS EN 1634-1.
The integrity of a fire door refers to its resistance to fire over time; if rated FD30, for example, it will give at least 30 minutes of protection; FD60, an hour's protection; and so on.
This is the rating system applied by the British Woodworking Federation (BWF) under their Certifire Fire Door and Doorset Scheme. Each doorset supplied to scheme specifications carries a permanent and tamper evident label.
Although certification is not necessary, and a fire risk assessor may consider a nominal (i.e. uncertified) fire door as capable of holding back a fire for a specified length of time, 3rd-party certification ensures that the products used in the manufacture and supply of fire doors are fit for purpose.
Installation of a fire door
The ASDMA definition of a fire door as a "complete installed assembly" highlights the fact that the installation - and maintenance - of a fire doorset is as important as the products used in its construction.
As such, although a competent professional can install a fire door, it is recommended that the work be carried out under the auspices of the Accredited Fire Door Installers Scheme. Developed by the BWF in association with FIRAS, the purpose of this scheme is to ensure that fire door installations are carried out correctly, safely and in compliance with current Building Regulations.
Further information: some useful linkswww.asdma.com