Fire Door Ratings: FD30 or FD60?
Fire Doors play a critical role in the fire safety of buildings by slowing down or stopping the spread of fire from one area to another.
They are part of the 'fire compartmentation' system provided by walls, floors and ceilings. One fire compartment can be a single room, or a number of rooms, a corridor or shaft. An example of a fire compartment could, for example, be one single flat in a block of flats, an escape corridor at a school or a staircase at a hospital. Where access to a fire compartment is necessary then the door providing access must be a fire door. This is because the door must provide sufficient fire and smoke resistance to provide protection for people using the corridor, for example, to safely escape or seek refuge in a fire situation. The most common specification for fire doors leading to escape routes are fire doors resisting fire for 30 minutes, called FD30 fire doors. Sometimes higher fire-ratings are necessary to help protect property or assets as well as to protect people. An example are FD60 fire doors, which resist fire for 60 minutes.
The above diagram shows how FD30s (the 's' after FD30 signifies, that the doors not only resist fire but are also able to stop the spread of cold smoke by having smoke brushes as well as intumescent strips) fire doors provide fire and smoke compartmentation for each flat. So the fire door from each flat should slow down or stop fire spreading from inside the flat and on to the corridor. There are additional fire doors that compartmentalise the corridor and the staircase. Therefore if a fire breaks out in one flat there should be thirty minutes protection on the corridor side and a further thirty minutes at the lobby adjacent to the staircase and so on.
The diagram shows how a fire door or series of fire doors used in critical locations can help to protect escape routes for people to use in a fire emergency. Additionally, the fire doors will also protect other parts of the building from fire and smoke damage.
Fire doors are available in various fire ratings to provide protection according to the needs that apply to the use of the building and those of the people that use it. So with the knowledge that fire doors are available with fire ratings of up to 240 minutes it can be seen how fire doors can be used as a tool to meet the fire strategy requirements of all types of buildings with varying fire risk based requirements.
When a building is designed, whether for new-build or for change of use, the fire safety will be part of the design requirements and it will be necessary to comply with local building regulations. Building regulations set minimum standards and these must be met as a legal requirement and the regulations also provide guidance about how those standards can be met or indeed exceeded.
Once the building is complete and has been handed over, the owners or managers have a statutory duty to comply with fire safety law. In England & Wales the law that applies is the Regulatory Reform (Fire Safety) Order 2005.
Local building regulations, in England & Wales, in the form of Approved Document B provide details about minimum requirements for fire safety. The most basic requirement is that "the building shall be designed and constructed so that there are appropriate provisions for the early warning of fire, and appropriate means of escape in case of fire from the building to a place of safety outside the building capable of being safely and effectively used at all times". Similar requirements exist in Scotland and Northern Ireland but in the form of different documents such as Technical Handbooks and Technical Booklets.
So the size, use and complexity of the building will be determining factors in how the above requirement may be met. Where safe escape is straight forward there may be no requirement for fire doors at all but in a complex building or where users may require assistance to escape then fire doors with higher fire ratings may be necessary. The building regulations provide details of compartmentation requirements and in Appendix B: Fire Doors of Approved Document B: Fire Safety, Table B1 states minimum requirements for fire doors depending on the position of the door in the building. For example currently the requirement is that a fire door in a compartment wall separating two buildings should provide sixty minutes (FD60) fire protection whereas a fire door affording access to an escape route should provide thirty minutes (FD30) fire protection.
Table B1 states a requirement for fire doors on flat entrances to provide thirty minutes protection and those opening onto an entrance lobby inside individual flats to provide twenty minutes. However, whereas the flat entrance door must be fitted with a suitable self-closing device there is no requirement for self-closing of doors inside individual flats. Landlords of course have no control over the actions of tenants inside flats and such doors are often left open so we can see that the building regulations are by no means a perfect solution in terms of fire safety. Further guidance on fire doors for flat entrances and inside individual flats is available in the document 'Fire safety in purpose built blocks of flats' at https://www.local.gov.uk/sites/default/files/documents/fire-safety-purpose-built-04b.pdf.
For businesses and HMOs current fire safety law places an obligation on the person or entity responsible for the building to take a risk based approach to fire safety. The 'responsible Person' must carry out a suitable and sufficient fire risk assessment and from that assessment the requirements for fire doors at locations at the building should be established. The fire rating for the doors must be suitable to meet the needs of the fire strategy at the building.
Other guidance for various building types is available, for example in health care there are 'Healthcare Technical Manuals' and these deal with fire safety in 'HTM05' and doors in 'HTM58'. So its important to understand that whereas a fire door to a staircase or cross-corridor at a block of flats may be only FD30 the same door at a hospital may need to be FD60.
FD30 or FD60?
Ultimately fire risk will depend on many factors from the likelihood of a fire starting, including assessment on whether the conditions that could support ignition and fuelling of a fire exist, to accounting for the particular needs, in an emergency, (PEEPS) for people that use the building.
So in situations where the building regulations apply, the requirements of Approved Document B must be met as a minimum requirement. In situations where the Regulatory Reform (Fire Safety) Order 2005 applies then the fire risk assessment must consider requirements for fire doors based on the risk factors present at the building. Only by ensuring that the fire risk assessment is suitable and sufficient will you be able to make a decision about locations where fire doors are required and the necessary fire ratings.
In the majority of situations and certainly in housing, other accommodation and on escape routes, for example, the fire doors will be required to restrict the spread of cold-smoke. This means that smoke seals must be installed correctly so that the brush, blade or fin is in contact with the opposing surface of the door or frame. This matter is often overlooked and risk assessors sometimes fail to notice that such seals are ineffective because of poor installation or wear and tear. Spread of smoke is known to present a serious danger and threat to life in a fire situation and so those responsible for fire safety must address this issue when considering requirements for fire doors.
Fire safety law places an obligation under Article 17 of the Fire Safety Order in England & Wales (similar requirements apply in Scotland & Northern Ireland but the legal documents vary locally) to ensure that fire doors are "subject to a suitable system of maintenance and are maintained in an efficient state, in efficient working order and in good repair". So it is important to carry out periodic inspections and address any maintenance and remedial issues. BS9999: Code of practice for fire safety in the design, management and use of buildings & BS8214: Code of practice for timber-based fire door assemblies both recommend six-monthly inspections. However, it is important that such a maintenance system satisfies the particular needs of the building.
Help and advice
The more complex the building then the more detailed will be the needs to meet fire safety requirements. Where you are at all unsure, you would be well advised to consult a professional that specialises in fire risk assessments and with particular regard to fire doors a CertFDI certificated fire door inspector. Safelincs offers such fire door inspections. Please contact us on 0800 612 6537 if you would like to arrange a fire door inspection.