The Ministry of Housing, Communities & Local Government (MHCLG), on 18th July 2019, finally issued a long expected short summary note of the results of the tests they initiated on timber fire doors on the advice of their Expert Panel (as part of the overall response to re-establish confidence after the Grenfell fire).
It’s all GOOD NEWS! Though no surprise at all to the specialist door sector.
Timber fire doors rated for 30 minutes fire resistance from 25 suppliers were tested in a standard furnace test of the type that has been carried out by door manufacturers many hundreds of times over the years. A total of 50 separate tests are recorded in the Ministry note, carried out from 15.10.18 to 16.03.19.
We now have the formal reporting of the results. All doors passed, very well. For the early tests the Ministry asked for testing to be terminated at 36 minutes. For the subsequent tests the test duration was extended to onset of integrity failure in accordance with the standard test criteria. Many of the doors succeeded in going beyond 35 minutes, some even going successfully beyond 50 minutes.
The results point to three main conclusions that should emphasise a high degree of confidence in timber fire doors:
a) High level confirmation of the performance of timber fire doors: no failures at all; and typically a significant safety margin test overrun for a number of doors.
b) Consistency of performance, from one supplier to another across the sector.
c) Confirmation of the established test convention for timber fire doors for the door to be tested in what is deemed to be the weaker leaf opening direction, into the furnace.
It is particularly important to note that the convention of testing timber fire doors with the leaf opening into the test furnace for symmetric door leaf constructions is suitably supported by the tests. That is a well-established rule, derived from testing over the years across the sector, in combination with an established understanding of the door technology in fire. The convention is supported by UK test houses in the testing they carry out. And is confirmed in the clauses of test standard BS EN 1634-1, based on a Europe-wide consensus as part of the EN standards process, as well as by BS 476 as a test principle.
ASDMA’s advice for timber fire doors remains as it has always been. That is for doors to be properly supported in-depth by a continuous process of both formal and research & development testing established over several years. Testing is carried out across the sector, not only by door manufacturers but also by main door component and door blank providers as well. There is, in effect, a tremendous multiplication of testing across the specialist timber door sector. That in-depth understanding of the door technology within the sector should be taken by specifiers, clients and authorities alike to provide a justified high level of confidence in the specialist door sector. Testing is a way of life.
Appropriate test evidence can be found in individual test reports and better from technical assessment evaluations which take into account a number of relevant and appropriate test reports that go together to define the scope of design and application. In addition, manufacturers should also be covered by third-party product certification, which includes regular review and auditing of product consistency, testing and factory control processes linked with overview of quality systems.
Fire doors are crucial to the fabric of a building in providing protection for escape routes and protecting the rest of the building from the spread of fire and smoke. In this function they help to save lives and reduce damage to the rest of the building by slowing down the spread of fire and smoke. New fire doors can be purchased in a huge range of designs and sizes but there are still occasions when it is preferable to upgrade existing doors rather than replace them. In this article we will look at guidance available and consider briefly the types of products used to upgrade.
What legal duty do you have in terms of fire safety and how might that influence decisions about fire doors?
The law that deals with fire safety obligations is the Regulatory Reform (Fire Safety) Order 2005 (RRO) which covers all properties except inside people’s private homes. It covers public buildings, places of employment, entertainment and leisure as well as the common areas of buildings that contain separate flats. This includes each individual flat’s entrance door coming from the common areas, which is required to be a fire door. The ‘Responsible Person’, which may be the employer, building operator or owner and possibly his agent has a legal duty to take fire precautions, so far as is reasonably practicable, to ensure the safety of his employees and relevant persons. He must take all reasonable precautions to ensure the premises are safe.
The Order also places an obligation on the Responsible Person to ensure 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’. It is, therefore, hard to escape the need for fire doors to comply with the benchmark fire performance tests BS 476-22:1987 or BS EN1634-1:2014. If we add another critical purpose of a fire door, namely smoke control, the fire door should also comply with the relevant performance test BS 476-31.1.
However, some historic buildings may be listed and, even though compliance with fire safety law is mandatory, for preservation reasons there will exist limitations about removal and replacement of doors. In these cases there is bound to be a strong argument for upgrading rather than replacement. So the challenge is to perform the upgrading works whilst maintaining compliance with the relevant fire safety standards and guidance.
Regulations, standards and guidance documents.
Building Regulations (Approved Document B) require that where the building is undergoing a change of use it is necessary to comply with the requirements of these regulations and in the appendix covering fire doors the regulations state performance requirements giving reference to British and European Standards. Therefore the upgrading works (due to building use changes) should comply with the relevant standards.
The British and European Standards mentioned in this article so far cover only product performance, but as Building Regulations also cover ‘materials and workmanship’, compliance with BS 8214:2016 ‘Timber-based fire door assemblies-Code of Practice’ should be ensured too. Once the building works connected with change of use have been completed then the building will be subject to the aforementioned Regulatory Reform (Fire Safety) Order 2005.
It may be that the need to upgrade is not due to any change of use but instead to improve fire safety in which case the works must comply with the requirements of the RRO. This brings us back to the benchmarks for fire door performance so in the next section we will look at product performance for the products used in the upgrading works as well as the standard of workmanship and ongoing maintenance requirements.
Before we move on, though, it’s important to consider the use to which the building will be put and any inherent features that may affect safe egress in an emergency. Complexity of the building and the vulnerability of the building users must be considered as part of the fire risk assessment which in turn will determine the level of protection required from each fire door. Fire doors are rated by the duration during which they provide fire separation performance. The ratings are FD20 (twenty minutes, now not used any longer), FD 30 (thirty minutes) and FD60 (sixty minutes). Where asset protection is a requirement, ratings of FD90 up to even FD240 are possible but these are very much specialist products necessitating bespoke survey, design, manufacture, installation and maintenance. The letter ‘s’ may appear after the rating (FD30s for example) and this indicates that cold smoke protection is also a requirement. Building operators, owners and their agents having fire safety responsibilities are well advised to consult guidance particular to the type and use of building in question. There exists additional guidance for blocks of flats, hospitals, care homes and tall buildings just as a few examples so doing some early research and taking expert fire risk advice will enable you to determine the required fire rating for your fire doors. We would recommend the consultation of an experienced Fire Risk Assessor for this purpose.
How to upgrade fire doors.
Strong timber doors can usually be upgraded to fire doors, as timber, when subjected to fire, forms a surface char and burns at a predictable rate according to density and there are multiple products available to upgrade timber doors to increase fire performance. However, one should be mindful that upgrading works may cost more than the replacement of the doors and that a high level of expertise is required if the job is to be done correctly. Screwing a board to one side of a timber door may be fairly easy but can you be certain how much fire protection that will provide?
Before we start with guidance on upgrading we must consider that in recent years fire safety protection has increasingly become reliant on evidence based reports and certification rather than the more prescriptive upgrading methods used ten or twenty years ago. It may be for this reason that guidance from the Fire & Rescue Service (taking West Yorkshire FR&S as an example) is that ‘increasing the fire resistance is not normally acceptable’. Their advice leaflet 25 http://www.westyorksfire.gov.uk/uploads/assets/sitepoint/pan/fireProtection-FS/FS-PAN025-DoorsUpgradeResistance.pdf goes on to say ‘where the reasons are considered valid by an enforcing authority it may be appropriate to modify the doors in order to provide an improved standard of fire resistance’ and points us towards guidance in the form of: Building Research Establishment Information Paper 8/82 “Increasing the fire resistance of existing timber doors” and the Timber Research and Development Association’s Wood Information Sheet, 1-32, “Fire Resisting Door-sets by Upgrading”.
With particular regard to heritage buildings English Heritage produced the 1997 guide “Timber panelled doors and fire”. This detailed and practical document addresses the issue of fire separation performance of existing doors whilst recognising the important need to minimise intervention and maintain reversibility. Those principles remain and the document, although twenty years old, is still used as a resource even though the industry has moved on. The fire door industry has invested heavily and achieved improvements in product performance so that where upgrading works are required, access to dedicated high performance products is widely available. These products vary widely and include intumescent edge seals, smoke seals, intumescent paints and varnishes, intumescent sheet materials, laminate boards as well as fire protection boards. The first step is to ensure that the door in question is suitable for upgrading, as doors made with thin timber panels, small frame dimensions or with a hollow internal core, for example, may not be suitable due to unacceptable levels of warping when subjected to fire. Door to frame clearance gaps are very significant in the performance of a fire door and should be checked and reduced to the required 2mm to 4mm. Anybody carrying out upgrading works should also ensure that the chosen upgrading product has been successfully tested or assessed to provide the required fire performance on that particular type of door construction.
Used correctly with strict adherence to manufacturers’ instructions these products improve the fire performance of a suitable timber door. However, there is much more to simply painting or over-boarding when attempting to upgrade a door to become a fire door. Correct choice of product is extremely important, for example the question of which type of intumescent fire seal should be used at the edges of the door will be determined by the construction of that door and the configuration in which it is used. Is the door a single leaf or double leaf? Is the door latched or unlatched? In a fire, double doors and unlatched doors will behave differently to single leaf doors and latched doors. It is essential to ensure the correct products and methods are employed and components such as self-closing devices, hinges, locks and latches should be assessed not only to ensure suitability but for optimum positioning, too. When working with fire doors and assessing or selecting suitable door hardware useful guidance is available in the code of practice ‘Hardware for Fire and Escape Doors’ jointly produced by the Guild of Architectural Ironmongers and the Door Hardware Federation. In addition it will be necessary to assess the door frame and the fire/smoke stopping between the frame and its supporting wall construction for suitability. Examples of recommended methods of sealing are contained in BS 8214:2016. So by following the above mentioned guidance documents, using fire performance products that are suitable for the door and fitting suitable door hardware we are able to upgrade our fire doors so long as the work is carried out competently.
Article 18 of the RRO states that “The responsible person must, subject to paragraphs (6) and (7), appoint one or more competent persons to assist him in undertaking the preventive and protective measures”. As far as fire doors are concerned this means that anybody carrying out upgrading works should be able to demonstrate competence in this field. It is a sad fact that due to a combination of lack of knowledge and financial pressure many fire doors installed in many buildings have been poorly installed and are therefore likely to fail to provide the intended fire performance. So whether deciding to fit new fire doors or to upgrade the existing ones one should always be careful to check the credentials of those employed to do the work. A good start would be to ask them to list the reference documents they would use relative to the works they will be undertaking. If they haven’t heard of those mentioned in this article then it’s likely that they do not possess a suitable level of competence.
The definition of certificate, in the context of this article, is “an official document attesting a fact”. Whether the certificate is worth the paper it’s printed on depends on the suitability of the performance test method, eg the quality control at the factory, storage and handling during distribution or the competency of the installer. The industry gold standard is Third Party Certification where a manufacturer, supplier or installer has attained certification by having a suitable quality management system in place, subjecting his products or services to suitable performance tests and having periodic audits of his working practices under an approved third party certification scheme.
One should bear in mind that when it comes to fire door upgrading works the product certification will cover only each separate component used in the upgrading process and is no guarantee that the works have been performed correctly. This means that it is not possible to certify the upgraded fire door as a whole, only the individual components used.
As with any important purchase one would be well advised to employ a buyer-beware strategy and insist that the installer agrees to an inspection of his work by a competent fire door inspector. After all this is potentially a life safety issue and if the building, its fabric and contents are of such importance that considerable expense has been invested in the upgrading works, therefore the inspection of the works by a qualified competent person is worth the extra time and expense.
All fire doors will require ongoing inspection and maintenance. Guidance on inspections and the intervals between inspections is available in British Standard documents BS 9999:2017 Fire Safety In The Design, Management And Use Of Buildings – Code Of Practice, and BS 8214:2016 Timber-Based Fire Door Assemblies -Code Of Practice.
Upgrading fire doors requires specialist skills, takes a longer time and requires higher expenses than replacing a door with new fire door but it can still be required in special circumstances. Many upgrading products are available. These together with specialist knowledge and skills from a competent installer can improve fire performance of doors. It should be remembered that listed buildings, from a preservation point of view, are national treasures and so investing in some of the knowledge and skills available can be necessary.
Winter is officially here, which means it’s a good idea to make sure that your fire protection systems are properly working for the cold weather. There are two types of fire protection systems, Active Fire Protection (AFP) and Passive Fire Protection (PFP). It’s important that both systems are properly working in the event of a fire. Active and passive fire protection systems are meant to work together during a fire, not one in place of the other. But, there still may be some confusion about the differences between active and passive fire protection.
Active Fire Protection is a group of systems that require some amount of action in order to work efficiently in the event of a fire. These actions may be manually operated, like a fire extinguisher or automatic, like a sprinkler. So, when fire and smoke are detected in a facility, a fire/smoke alarm will alert those who are inside the building and work to actively put out or slow the fire. Sprinkler systems and fire extinguishers help slow the growth of the fire until firefighter have a chance to get there. Once firefighters arrive, they use fire extinguishers and fire hoses to put out the fire altogether.
Passive Fire Protection is a group of systems that compartmentalize a building through the use of fire-resistance-rated walls and floors, keeping the fire from spreading quickly and providing time to escape for people in the building. Dampers are used in facilities ducts to prevent the spread of fire/smoke throughout the building’s ductwork system. Fire doors help compartmentalize a building while giving its occupants means of escape. Firewalls and floors help separate the building into compartments to stop the spread of fire/smoke from room to room. For building with multiple floors, photoluminescent egress path markers help light the way to safety in dark and smoky stairwells.
Active and passive fire protection systems, although different, are important to a building’s overall fire safety. AFP uses systems that take action in putting out the fire, while PFP uses systems that help prevent the spread of fire and smoke. Just because one is working doesn’t mean you should ignore the other, or that one is more important than the other. AFP takes action in putting out the fire, but may not always work properly. Especially during winter, sprinklers often fail due to frozen pipes, roads could become icy, and hydrants could freeze, which all delays a firefighter’s job and lets the fire grow. PFP compartmentalizes a building into smaller sections to prevent the spread of fire and smoke throughout the building, while also providing occupants more time for evacuation. However, it doesn’t put out the fire altogether, it just helps contain it to one location. Therefore, to ensure that a building has total fire protection, both AFP and PFP should be working together in unison.
As its name suggests, passive fire protection (PFP) is a form of fire safety provision that remains dormant, or inert, during normal conditions but becomes active in a fire situation. It is an integral component of structural fire protection in a building, which is designed to contain fires or slow their spread. The purpose of PFP is to contain the spread of fire for sufficient time to permit i) the safe evacuation of all occupants of the premises and ii) the arrival of the fire brigade. The person responsible for fire safety also has a duty of care towards any members of the emergency services, e.g. fire fighters, who may have to enter the premises during the course of a fire; in slowing the spread of flames, smoke and hot gases, PFP also serves to ensure the building remains as safe as possible for entry in this situation.
PFP: what and where?
PFP provision is required in all buildings, whether domestic or non-domestic, with the purpose of containing / compartmentalising / retarding the spread of fire.
There are several methods and products available that will achieve the required standard of fire resistance in existing buildings, some of which may be more appropriate than others. If you have any doubts about the best way to ensure PFP provision in your premises, you should seek the advice of a competent person. Any new build / modernisation / extension works must be carried out in accordance with The Building Regulations 2010, Fire Safety, Approved Document B.
In respect of internal fire spread (structure) and the relevance of PFP in particular The Building Regulations 2010 (Volume 2, p 67) stipulate the following (Requirement B3):
Where reasonably necessary to inhibit the spread of fire within the building, measures shall be taken, to an extent appropriate to the size and intended use of the building, comprising either or both of the following –
(a) sub-division of the building with fire-resisting construction;
(b) installation of suitable automatic fire suppression systems.
The building shall be designed and constructed so that the unseen spread of fire and smoke within concealed spaces in its structure and fabric is inhibited.
In respect of the protection of openings and fire-stopping in order to inhibit the spread of fire, 10.2 of the Regulations states (p 85):
If a fire-separating element is to be effective, every joint or imperfection of fit, or opening to allow services to pass through the element, should be adequately protected by sealing or fire-stopping so that the fire resistance of the element is not impaired.
There are two main types of opening that could compromise the integrity of a fire resistant structure: openings for pipes (10.5); and ventilation ducts, flues, etc. (10.9). At 10.17, additional provisions in respect of fire-stopping are detailed as follows:
joints between fire-separating elements should be fire-stopped;
all openings for pipes, ducts, conduits or cables to pass through any part of a fire-separating element should be:
a) kept as few in number as possible; and
b) kept as small as practicable; and
c) fire-stopped (which, in the case of a pipe or duct, should allow thermal movement).
Every service that is installed in a building, such as water pipes, electrical sockets, cable trunking and lighting units, can compromise the fire resistance of a room by creating openings in its walls, floor and ceiling. The role of PFP is to seal the gaps these penetrations create should the worst happen and fire break out. All products designed to fulfil this criteria are fire rated, i.e. certified to resist fire for a specified length of time, which can be anything from 30 minutes to 4 hours. They all include an intumescent material, which remains dormant, or passive, during normal conditions but swells to many times its original size when exposed to the heat of a blaze.
Examples of PFP
Fire doors, whose purpose is to contain a fire / protect a designated fire escape route, should be fitted with intumescent fire and smoke seals, either around the edges of the door leaf or the frame. These seals are an integral part of a fire door structure and ensure that, not only is the spread of fire prevented, but also and more importantly the ingress of cold smoke in the early stages of a fire. Smoke is known as the silent killer as it can overwhelm the occupants of an enclosed area long before the heat and flames of a fire are sensed.
The hot gases of a blaze can also move swiftly around a building, undetected at first, for example through air conditioning ducts. Intumescent air transfer grilles, which are typically 30 or 60 minute fire rated, allow air to circulate freely around a building under normal conditions, but the intumescent material swells and creates a barrier to restrict the passage of hot gases in a fire situation. They are suitable for use with both fire rated doors and compartment walls.
Intumescent pipe wraps and collars are designed for use on plastic pipes that pass through masonry floors and walls; the intumescent material expands inwards in a fire situation to squeeze the collapsing pipe until the opening is completely sealed.
Intumescent downlighter covers and fire hoods / canopies for recessed light fittings prevent fire from penetrating the ceiling void and thus preserve the fire resistant integrity of the ceiling; they are typically 30 or 60 minutes fire rated.
Electrical sockets in walls and skirting boards are another vulnerable point in a fire rated compartment; intumescent socket box inserts / covers expand to fill the electrical box in a fire, preventing the spread of flames, smoke and hot gases.