Fire door are an integral part of a building’s passive fireproofing plan. They’re used for fire compart mentation – a process that places physical barriers in strategic areas around a building, in order to slow the spread of flames and smoke in the event of a fire. In this post, we explain what they’re made out of, how much protection they offer, and when they’re required by law.
What are fire doors made of?
Fire doors can be made with a combination of timber, steel, gypsum, and aluminium. They can also have windows, which are made from borosilicate or ceramic glass (both of which offer a higher fire resistance than standard glass), and may contain an anti-shattering wire mesh.
To enhance their fire-stopping abilities, fire doors are flush with the frame; any gaps are filled with silicone-based fire-resistant sealant. These are often accompanied by an intumescent strip attached at the base of the door, which expands when exposed to heat to prevent smoke from seeping underneath.
Fire doors are commonly designed to include a closing mechanism. Usually fitted at the top of a door, these spring-loaded or hydraulic mechanisms force the door closed, preventing fire and smoke from passing from one area to another.
It’s worth mentioning that whilst many doors may contain some or all of these features, they may not necessarily be ‘fire doors’. To be called a ‘fire door’, a design must be certified by a manufacturer. Fire door certification is awarded once a door has passed various tests at an approved centre, including a fire and stress simulation. You can tell which doors have been certified by a label attached to their top edge, which states the manufacturer, date of manufacture, and designated fire rating (more on this below)
How long does a fire door protect you for?
There are different grades of fire door, and each one provides a different level of protection. The grades are separated by how long they can withstand fire. The main ones are FD30 (30 minutes), FD60 (60 minutes), FD90 (90 minutes) and FD120 (120 minutes).
The main aspect that differentiates the grades is the ‘certified core thickness’ of the doors. This is the core material of the door over which there can often be aesthetic layer of different material.
FD30 and FD60 are generally used internally for offices and residential buildings. Any grades over FD60 are more common for the protection of highly-valued properties or core infrastructures (for example, archives or server centres)
When are fire doors required?
All regulations pertaining to the use of fire doors are contained in Fire Safety: Approved Document B and following incorporations. According to the legislation, fire doors are required in domestic buildings over 2 storeys high; each door leading to a stairwell (at every level) from a habitable room (not a bathroom, for instance) must be a fire door. For commercial or non-domestic buildings, fire door requirements vary according to whether escape routes are vertical or horizontal (down stairs or through corridors).
If you’re looking to get your building (whether residential or commercial) in line with current fireproofing regulation, get in contact with CLM Fireproofing. As the UK’s leading provider of passive fireproofing services, we ensure full compliance with the latest standards.
To put it simply, fire doors save lives. Here, IFSEC Global provides a useful beginner’s guide to fire doors, their purpose, and crucial features to bear in mind when specifying, installing or purchasing them as part of a passive fire protection strategy.
What is a fire door and what are they designed to do?
Fire doors are specialist doors which have been tested against the elements and purpose-built to withstand roaring fires for as long as possible. They enable buildings to compartmentalise and delay the spread of fire from one area to another, and form a crucial part of a passive fire protection strategy.
Certified fire doors will be given a fire-resistance rating, which details the length of time the doorset and its materials will be able to withstand smoke and fire – either 30 or 60 minutes, depending on the rating. They are fitted with intumescent strips (or seals) which expand to fill the gap between the door and the frame.
Fire doors have a few vital safety features and really can be the difference between life and death. Two of the most important functions fire doors have are:
How often should fire doors be checked?
Because of their importance in protecting lives, it is imperative that fire doors receive regular inspections – frequency is likely to depend on many factors, including the age and condition of the door, though the British Woodworking Federation, which runs the annual Fire Door Safety Week campaign, says that periodic checks should be carried out every six months as a minimum.
However, newly occupied buildings may require more frequent checks in the first year of use, while doors with high traffic volume should be checked on a weekly or monthly basis. These fire doors are far more susceptible to damage because of more frequent use, and will likely also form an important barrier in the event of a fire to communal areas – particularly in multi-residential housing blocks.
Worryingly, the Fire Door Inspection Scheme (FDIS), which carries out checks on fire doors, found that three quarters of all fire doors inspected in 2021 in the UK were condemned as not fit for purpose. The scheme found similar results in 2019 after carrying out inspections, as it highlighted that all users should report maintenance issues and play a proactive role in ensuring faults are quickly addressed.
If you own a commercial or non-domestic property, there are strict regulations and guidelines to follow, ensuring the doors can withstand certain heats. Fire doors should always be fitted correctly by a competent installer, as they’re a carefully engineered fire safety device. It is also imperative that reputable and trained fire door inspectors, such as those approved by schemes like FDIS, carry out fire door inspections and trained installers fit them to ensure they are fit for purpose.
Under the Regulatory Reform (Fire Safety) Order 2005 (FSO), landlords have a responsibility to ensure their properties and tenants are safe. The ‘responsible person’ has a legal responsibility under the FSO and can be criminally prosecuted if they do not fulfill their duties. The responsibility extends to the requirement for a fire risk assessment in all non-domestic buildings, including the common parts of flats or houses with multiple occupation.
In addition, the Fire Safety Act 2021, amended the Regulatory Reform Order to bring clarification on fire doors being included in fire risk assessments where buildings contain two or more sets of domestic premises (multi-occupancy). This means that Responsible Persons, such as the building owner or manager, must now review fire risk assessment for flat entrance doors in addition to the communal areas and implement a suitable system of maintenance
ll components are required to adhere to product certification requirements that are acceptable to the local Authority Having Jurisdiction (AHJ) by meeting the requirements of the local building code and fire code. The regulatory requirement change from country to country. For example, in Australia, the National Construction Code dictates that all fire doors must be tested to certain specifications in order to meet resistance approvals and certification.
In the United Kingdom a fire resisting doorset should be subjected to either a British Standard Fire Test BS 476 Part 22 1987, or a BS/EN 1634-1 2000 test. The results are recorded by the test agency and provided in a report which detail such things as constructional details, distortion data and pressure readings. The numerical fire resistance rating that is required to be installed in a particular building is provided in the Building Regulations approved Document B, or British Standards such as the BS 5588 series (e.g., 30 minutes FD30, or FD30(S) if cold smoke resistance is also required). Classifications in use which reflect the number of minutes of fire resistance offered are FD30, FD60, FD90 and FD120.
Similar technical guidance documents and building regulations are in effect in other countries.
Fire doors are not necessarily noncombustible. It is acceptable for portions of the door to be destroyed by combustion during exposure to fire as long as the door assembly meets the fire test criteria of limiting temperature on the non-fire side of the assembly. This is in accordance with the overall performance goal of a fire-rated door to slow fire propagation from one fire rated compartment to another for only a limited amount of time, during which automatic or manual fire fighting may be employed to limit fire spread, or occupants can exit the building. Fire doors are made from a range of different materials such as timber or steel. Despite not being fire resistant, timber is used as it has a very predictable char rate, depending on the density and the moisture content timber generally has a char rate of 0.5mm per minute for hardwood and 0.7mm per minute for softwood.
Fire door failure
Fire doors are sometimes rendered unable to provide their listed fire resistance by ignorance of the intended use and associated restrictions and requirements, or by improper use. For example, fire doors are sometimes blocked open, or carpets are run through them, which would allow the fire to travel past the fire barrier in which the door is placed. The door’s certification markings are displayed both on the door leaves and the fire door frames, and should not be removed or painted over during the life of the building.
Sometimes fire doors have apparently very large gaps at the foot of them, an inch or two even, allowing air movement, such as in dormitory facilities. This can lead the occupants of a building to question their status as ‘real’ fire doors. NFPA 80 allows a maximum door undercut of 3/4 inch, however fire doors are tested with smaller clearances in accordance with NFPA 252. Corridors have a fire rating of one hour or less, and the fire doors in them are required by code to have a fire rating of 1/2 or 1/3 hour, the intent of which is mainly to restrict smoke travel.