Originally posted 17th May 2017
The purpose of external (and internal) fire doors
They serve three main and overlapping purposes:
- First of all, they are designed to restrict the initial development of a fire. If the fire door is correctly fitted and functioning as designed it can help to suppress a fire by restricting the amount of oxygen available to it
- Secondly, they are designed to restrict the spread of fire. A closed fire door will endure “direct attack” for a specified period of time, restricting the spread of fire thus allowing safe evacuation and for resources such as sprinklers and fire-fighters to perform their functions
- Thirdly, to protect escape routes. As we saw last time, the provision of protected escape routes is a key requirement of Building Regulations. Any door opening onto an escape route or operating across an escape route will almost certainly be designated as a fire-resisting door. This will ensure not only that people are protected from the fire as they evacuate, but also that fire-fighters entering the building will enjoy some protection
Differences between internal and external fire doors
An internal fire door is designed to compartmentalise a section of a building in the event of a fire and protect an escape route through it for a minimum length of time (typically between 30 and 240 minutes).
An external fire door is, by definition, at the end of an escape route (i.e. at the boundary to the outside and safety) and differs in two fundamental ways:
- it does not need to have fire resisting properties
- it does not need to be kept closed
Its purpose is to enable the swift exit of people to safety.
We’re sometimes asked whether a designated fire exit can also legally be used as a regular entrance/exit door i.e. for everyday use. If you think about it, the fact that it is in daily use makes it ideal as an escape route as its location is very well known! So the answer is a resounding yes.
There is, of course, a security issue, given that the external fire door opens onto the outside, but that aside you just need to make sure that it complies with the regulations for fire doors (e.g. how it is opened from the inside and that it is well signposted) and that it is never blocked. Now let’s consider the security issue.
The security issue of external fire doors
The fact that external fire doors open onto the outside world, and (reference the regulations) “must not be so locked or fastened that they cannot be easily and immediately opened by any person who may require to use them”) causes an obvious tension between the two functions.
This tension is recognised in the various Government guides to fire safety risk assessment in public and commercial premises published by the Department for Communities and Local Government (DCLG). For example, the guide to “Large Places of Assembly” (May 2006) states that “guidance on fire exits starts from the position that doors on escape routes should not be fitted with any locking devices”, but goes on to note that the security aspect can be addressed by the installation of dedicated hardware that prevents unlimited access but still enables the occupants of a building or area to open the door easily if there is a fire.
This leads us onto the different types of external fire door.
External fire door alternatives
- “panic” or “push” bars. We’re all familiar with these. As the name implies, they are easy to operate in a panic situation simply by pushing down. Clearly they are only suitable for doors that can only open outwards, and must be clearly labelled (e.g. PUSH TO OPEN). These are particularly effective when large numbers of people are evacuating quickly, as minimal pressure is required to release the locking mechanism
- emergency or “push” pads. Similar to panic bars, but are small pads instead of horizontal bars. They should of course also be accompanied by a sign explaining the mode of operation. These are suitable for doors where panic is unlikely (e.g. for the exclusive use of staff intimately familiar with the building layout) and NOT for the general public
- the use of so-called “barrel bolts”, but with the stop (which prevents the bolt from being withdrawn too far) removed at installation. Although frequently used in the past, these are not recommended – particularly if the door is the ONLY means of escape – as they can occasionally stick and thus make the bolt difficult to withdraw
- Redlam bolts. These bolts fit into a tube, which when broken automatically slides back the bolt and unlocks the door. As with push pads, they are only suitable for use by staff and NOT for the general public
- Kingpin emergency bolts. Similar to Redlam bolts, these have a handle which when pulled releases the spring-loaded bolt and unlocks the door.
These solutions are suitable for the vast majority of exit fire doors. There are some premises, however, such as high security buildings, where other more sophisticated mechanisms need to be employed (e.g. mechanisms relying on electromagnetism such as Maglocks or Shearmags).
What the law says about external fire doors
As we’ve often covered, fire safety – quite rightly – is heavily regulated, and business owners need to be very careful that they adhere to all the regulations. There are two in particular that we’ll bring to your attention:
These set out your responsibilities to employees and visitors around a range of subjects, and it’s important that you’re fully aware of what they are.
For new buildings, or buildings which are subject to major alterations, extensions, or changes of use, there are specific building regulations that apply to fire doors. The regulations are referred to as approved documents, and here is a useful link to find them.
Existing buildings are covered by the Regulatory Reform (Fire Safety) Order 2005, often abbreviated to RRO or FSO. This reform stipulates that the responsible person must carry out a fire safety risk assessment and then design and supervise the operation of a fire management plan.
You should also be familiar with Regulation 38 of the Building Regulations (England and Wales). It stipulates that fire safety information should be provided to the “responsible person” at the completion of a project (or when the building is first occupied).
The information provided should include all fire safety design measures in appropriate detail and with sufficient accuracy to assist the responsible person in operating and maintaining the building safely, including the fire doors.
The contractor is responsible for handing over this information to the client or their appointed representative, and this could vary considerably according to the nature of the building or contract. Typical recipients are likely to be a Health and Safety or Environmental Health Officer , client’s surveyor or architect, or building project manager responsible for the final sign-off of the building contract. In turn, the client should then provide the relevant information to the “responsible person”.
And now the good news
We’re specialists in this field, which means that apart from being able to provide you with exactly the right doors, we know all you need to know about the regulations, so don’t worry you don’t need to familiarise yourselves with them … leave that to the experts!
We specialise in the manufacture and installation of external fire doors – and can give you excellent advice and guidance based on years of successful installations and a large and satisfied customer base.
As always we’ll be delighted to help and advise you.