Fire Doors & Shutters

BACKGROUND

This Technical Bulletin has been produced in response to serious concerns expressed by fire safety organisations and professionals relating to the poor specification, installation and maintenance of fire doors. The bulletin aims to provide a general summary of some the key considerations which apply in respect of the design, installation, maintenance and identification of fire doors and shutters.

Research carried out in 2016 by registered inspectors of the Fire Door Inspection Scheme (FDIS) (this scheme will be discussed later) identified serious issues around the effectiveness of UK fire doors in holding back smoke and flames in the event of a fire.

Inspectors visited 31 sites and looked at 677 timber doors in the FDIS analysis. The research uncovered 2,506 faults on the fire doors inspected, which raises concerns about the wider picture across UK buildings.

The research found that:

• Over 61% had fire or smoke seals which were either missing, installed incorrectly or not filing perimeter gaps correctly.

• More than a third had incorrect signage.

• 230 fire doors inspected had excessive gaps between the door and its frame (i.e. over 3mm).

• In excess of 20% had unsuitable hinges.

• Almost one in six had damage to the door leaf.

Increasing evidence is also coming to light of newly installed fire doors not being installed in accordance with manufacturers’ instructions or even in accordance with industry best practice. In response to these concerns, an annual national awareness campaign under the banner ‘Fire Door Safety Week’ has been established.  

Consultants will also be only too aware of faults in steel fire doors and shutters which are commonly observed in the field, including such defects as:

• Doors or shutters, including the frames and supporting construction in poor condition having suffered impact damage.

• Doors or shutters failing to close property arising, for example, by lack of maintenance or the presence of obstructions.

• Whilst not as a result of a physical fault condition, uninsulated steel doors and shutters unlikely to prevent fire spread from heat radiation, owing to the close proximity of combustible storage.

BUILDING REGULATIONS

UK Building Regulations provide guidance as to the minimum building standards to be achieved, which for fire safety is contained in the following documents:

• Building Regulations for England and Wales – Approved Document B

• Scottish Building Standards – Technical Handbook 2

• Building Regulations in Northern Ireland – Technical Booklet E

Fire doors are required in almost every non-residential building constructed in the UK (also, many residential buildings) in accordance with the relevant national fire safety regulations in connection with compartmentation, means of escape and in some cases providing the emergency services with a protected route to access the building. These regulations contain reference to the relevant British and European Standards which define the test requirements and performance for fire doors. Fire doors can also be installed as an outcome of a fire risk assessment to further protect life and property.

For the purposes of this bulletin, fire doors have been divided between:

1.      Timber fire doors

2.      Firebreak doors and shutters

TIMBER FIRE DOORS

Most timber fire doors are nowadays of composite construction, typically involving solid cores of particle board or laminated veneer lumber, which are finished with decorative facings and lipping. It is normal for intumescent seals to be located in the door edge or frame. The historical reliance on door stops and rebates to provide fire resistance around the edges of the door has for many years been considered of limited value. 

BS 8214 - Code of practice for fire door assemblies gives recommendations for the specification, installation and maintenance of fire doors. The recommendations are applicable only to hinged or pivoted pedestrian doorsets, door assemblies, or door leaves of any material, fitted into frames of any material, and only applies to doors that are designed to provide fire resistance ratings of up to and including 120 minutes.

It was once accepted practice to improve the performance of an existing door to provide fire-resistance, for instance by lining with a fire-resisting material. Nowadays, outside of small domestic projects or listed buildings, this is no longer likely to be approved by Building Control. Architects should therefore only specify ‘certified’ fire doorsets, both for identification purposes and to guarantee their performance in a fire situation.

It is important to recognise that Building Regulations relate to the entire door installation, and not just the door alone. As result, fire doors are tested as a complete installation (referred to as a ‘doorset’), including the frame, seals, any glazing, locks, latches and other essential ironmongery. Testing is carried out to the requirements of either BS 476: Part 22 or EN 1634-1 of which UK ratings are as follows

In addition to specific fire performance testing of the doorset, certification may also be obtained by a door manufacturer via an assessment of the doorset design by a qualified fire engineer using existing fire test data in lieu of a specific test. This should be conducted in accordance with guidance published by the Passive Fire Protection Association. Fire rated timber doorsets can also be made using a door manufacturer’s proven door blank and global assessment data.

In addition to being supplied as a doorset (defined in BS EN 12519 as ‘a complete unit consisting of a door frame and a door leaf or leaves, supplied with all essential parts from a single supplier”), doors are also made up on site as fire door assemblies (defined as “a complete assembly as installed, including door frame and one or more leaves, together with its essential hardware supplied from separate sources”). As far as the later are concerned, it is essential that the door manufacturer’s installation instructions are observed, to ensure the sourcing and installation of the correct and compatible door assembly components. Irrespective of the type of fire door, the importance of correct installation cannot be overstated.     

In many cases, doors are required for both fire and smoke control in which case smoke seals as well as intumescent seals with be provided in either the entire perimeter of the door or in the surrounding frame. Often a combined intumescent fire and smoke seal will be employed. Doors which have been certified for fire and smoke control are identified by the ‘S’ prefix – e.g. FD30S.

The gap between the door and the frame is extremely important and must be suitable for the intumescent seal fitted. In general, the gap should not normally exceed 3mm along the two long edges and across the top of the door leaf. The gap at the bottom of the door is usually around 10mm for non-smoke control conditions (extensive fire tests have proved that failure at the threshold is unlikely, owing to negative pressure at the threshold resulting in cool air being drawn in underneath the door), but 3mm when smoke seals at the threshold are required. Gap dimensions should always be in accordance with the door manufacturer’s recommendations.

The two main UK UKAS accredited testing and certification schemes for timber fire doors are as follows:

•  BM TRADA Q-Mark Fire Door Manufacturer Scheme

There is a legal requirement for manufacturers of fire doors to provide proof of the ability of their products to resist the passage of fire through the provision of test evidence.Whilst this demonstrates that the door meets the legally acceptable minimum standards, the BM TRADA Q-Mark fire door manufacturer scheme can provide additional reassurance that products are fit for purpose through ongoing compliance to the original product specification. The aims of the scheme are to:

• raise the on-going standard of fire door manufacture

• ensure on-going compliance with the original product specification

• maximise the product's service life

• provide peace of mind that the manufacturer is consistently producing a quality product through independent verification by a third party certification body.

The certified fire rating and other product information is displayed on the door and frame by the insertion of a series of colour coded core plugs, the key to which is shown overleaf. This colour coding information is available on a laminated plastic card, which Consultants can obtain by contacting BM TRADA on 01494 840774.

• BWF Fire Door Alliance Scheme (formerly the BWF-CERTIFIRE SCHEME)

  
  

The BWF Fire Door Alliance Scheme established by the fire door manufacturing industry, aims to promote the importance of using third party certificated fire doors and components as critical part of any passive fire protection plan.

Every BWF Fire Door Alliance fire door - carries a permanent label indicating the fire resistance rating (and smoke resistance, where applicable) as per the following examples:

To avoid tampering, labels are normally affixed to the top edge of the door.

Label’s indicating a certified FD30 door with a certified glazed aperture

Needless to say, the cutting of a fire door, for example, to accommodate a sloping ceiling or the planting of an additional piece to make up a non-standard size is likely to invalidate its certificate. The fixing of a lock, letter plate or vision panel to a fire-resisting door could also invalidate the certificate. Vision panels must never be cut in on site but preferably be factory-fitted and delivered ready glazed with the correct type of glass. The glazing of pre-cut apertures on site is permitted, but must be undertaken by a trained and competent installer in accordance with the instructions provided by the door manufacturer.

Lastly, the type of smoke or fire seal should be chosen carefully as not all intumescent materials act in the same way. Changing the specification from the tested assembly can have unexpected results. There are two types of seal - low-pressure seals (which expand in all directions, but do little to prevent distortion) and high-pressure seals (which exert pressure in one direction and help prevent distortion of the door leaf) - swapping them can again affect performance.

Important Note: Where installing fire-resisting glazing in doors or, for that matter, any other application, it is fundamental that fire-resistant glass must only be used as part of a fire-resisting glazed system – which includes the glass, the glazing seal, beads, fixings and frame. All the essential components of such a system must be compatible under fire conditions, and the performance must be referenced to appropriate and relevant test evidence.

A typical assembly for fire resisting glazing in a timber fire door

TIMBER FIRE DOOR IDENTIFICATION

In the absence of visible identification labels or other markings, as a general rule of thumb, doors 44mm thick fitted with 10-15mm wide intumescent seals are likely to be FD30, whilst doors 54mm thick using at least 20mm width of intumescent seal, fitted as one or two strips, are likely to be FD60. Timber fire doors with a rating in excess of FD60 are rarely employed on escape routes or to protect people, but may be encountered for property protection.

Owing to the weight of the door and to prevent it warping, fire doors are invariably fitted with three hinges and will be provided with self-closing devices.

Lightweight hollow flush doors will not be FD30.

INTUMESCENT FIRE AND SMOKE SEALS

The intumescent fire and smoke seals that are fitted to fire doors are wide ranging in material, colour and specification. They can be manufactured separately or combined as one seal and can be located in the door edge or frame. Key considerations include ensuring that:

• Seals are compatible with the door leaf and frame, and are correctly fire rated.

• The correct gap as specified by the manufacture is achieved and maintained between the door and the frame.

• Seals are approved by a recognised fire approvals scheme. 

Depending on the door manufacturer’s test evidence and installation instructions, door ironmongery such as hinges may require to be fitted with intumescent pads to provide thermal protection to the door and frame. Invariably, this will always be the case for FD60 doors where a higher fire performance is required.

TIMBER FIRE DOORS – INSTALLATION AND MAINTENANCE

It is a legal requirement under UK Fire Safety Legislation that fire resisting doors and escape doors are correctly installed and maintained in order for them to be fit for purpose.

It is vitally important that fire doors are installed and maintained by suitably competent and trained persons in accordance with the manufacturer’s/supplier’s instructions. In response to this need, the BWF Fire Door Alliance Scheme has established a contractors register embraces contractors that are members of one of the following approved third-party door installer schemes:

• FIRAS - A voluntary third-party certification scheme for installation contractors of both passive and active fire protection systems, operated by Warringtonfire.

• Trada Q Mark Fire Door Installer Scheme - A voluntary third-party fire door installer and maintainer certification scheme operated by BMTRADA.

A further response to the need for inspection competency has been the creation of the Fire Door Inspection Scheme (FDIS), being a joint venture between BWF-CERTIFIRE and the Guild of Architectural Ironmongers. The scheme provides an online learning centre leading to diploma and a route to becoming a certificated fire door inspector, details of which can be found at www.fdis.co.uk. 

Periodic inspection of timber fire doors should be carried out at least once every six months as recommended in BS 8214. Newly occupied buildings may require more frequent checks as will doors subject to high traffic and therefore more susceptible to damage (e.g. once per week/month depending on usage).

The following general advice on the checking of fire doors is published under the banner of Fire Door Safety Week:

FIREBREAK DOORS AND SHUTTERS

For the purpose of this Technical Bulletin, the term ‘firebreak doors and shutters’ relates to various types of fire-resisting doorsets and shutter assemblies ranging from between 90 and 240 minutes fire-resistance, in support of the compartmentation recommendations of the RISCAuthority/FPA Design Guide for the Fire Protection of Buildings and the objectives of property and business protection, allied with insurers requirements for firebreak wall divisions for risk separation purposes.

Steel doorsets are normally supplied in factory assembled or knock-down form for site assembly, complete with all approved components. Fire certification can be in the form of full independent testing, or for bespoke applications, based upon the manufacturer’s existing test data for the generation of an independent fire assessment.

With the exception of a few highly specialised door designs, a steel fire door performs differently to a timber door and does not normally require the provision of intumescent seals, owing to the fact that in a fire the door rapidly expands to seal the gaps between the door leaf and the surrounding frame. However, in areas of special risk or high value, the provision smoke seals may require to be considered.

The testing and approval of firebreak doorsets and shutters are the subject of LPS 1056: Test and Evaluation Requirements for the Approval and Listing of Fire Doorsets, Lift Landing Doors and Shutter Assemblies. Under this LPS, various products are listed with fire resistance ratings for integrity and insulation of between 90 and 240. It is important to note that some listed products whist having an excellent rating for integrity, have a zero rating for insulation, and where such products are encountered in the field, it essential that particular attention is given to ensuring that combustible materials are kept clear to suitable distance to prevent the spread of fire from radiated heat.

Steel fire doors and shutters should always carry a nameplate that includes the fire rating, the manufacturer’s name, date of manufacture and a unique serial number for traceability. 

The approval of installers of fire door and shutter assemblies falls under LPS 1271: Requirements for the LPCB Approval and Listing of Companies installing fire and security doors, doorsets, shutters and active smoke/fire barriers. Firebreak doors and shutters should be maintained under contract (at least annually) by a company approved to LPS 1197: Requirements for the LPCB Approval and Listing of Companies inspecting, repairing and maintaining fire and security doors, doorsets, shutters and active smoke/fire barriers. In addition, formally recorded user tests and inspections should be conducted at appropriate intervals to check for damage and to confirm correct operation.

The UKAS accredited third-party approval and certification of ‘firebreak’ doors and shutters, together with installation contractors is not exclusive to the LPCB, but is also operated by Warringtonfire under its CERTIFIRE and FIRAS schemes, full details of which can be found at www.warringtoncertification.com

Nowadays it would be a fairly rare event to encounter firebreak doors or shutters that are manual in operation, but where this is the case, at risk of stating the obvious, it is essential to ensure that they are manually closed out of working hours. Where possible, manual closure of automatic doors and shutters is also recommended during idle periods as this increases the reliability of protection and helps to detect potential mechanical problems.

Where dealing with the protection of conveyor openings in fire walls, special considerations will apply.

FIREBREAK DOORS AND SHUTTERS – STORAGE CONSIDERATIONS

To assist in ensuring effective operation of firebreak doors and shutters, it is essential that these are maintained clear of the storage of goods and materials at all times. A minimum 1m clearance from the face and sides of the firebreak door or shutter is common ‘best practice’ for insulated products. With sliding doors, avoiding obstructions when in the open position is of paramount importance, not just from the direct face of the door, but also from closing weights and other parts of the operating mechanism. Closing and other weights on which correct operation of the door is dependant should be provided with metal enclosures.

Guard posts, barrier rails or hatched floor markings to delineate the clearance required should be provided as appropriate. 

In addition to the risk of impedance by goods and materials, uninsulated doors and shutters pose a serious risk of fire spread by radiation heat transfer, which invariably demands far greater clearance distances than the minimum 1m referred to above.  The safe storage distance for combustible materials is influenced by a number of factors, including the intensity of the radiation (from fire test data), the area of the radiating surface and the height/width ratio, and the susceptibility of the stored goods/materials to ignition by radiation.

When double uninsulated door or shutter assemblies are installed, one on each side of the opening, the safe distance from combustible materials can be reduced. The presence of effective sprinkler protection is also likely to have a favourable influence on spatial requirements.

The following guidance on the matter of safe storage zones has been taken from the RISCAuthority/FPA Design Guide for the Fire Protection of Buildings:

Figure 1. Shows the recommended safe distances (m) for the positioning of combustible materials from an uninsulated 90, 120 and 240 minute fire-resisting doors or shutters based on an area of door (m²) and assumes that the height and width are the same (since this in radiation terms presents the worst case in terms of maximum radiation intensity from the centre of the door).

Figure 2. Shows the recommended safe distances as per Figure 1, but for circumstances where double doors or shutters are installed.

Figure 3. Establishing the limit of a zone which is safe from the effects of heat radiation, taking account of the fact that a reduction in radiation occurs away from the centre of the door or shutter.

In reality, the semi-circular profile outlined in Figure 3 is unlikely to be compatible with racking layouts commonly encountered in storage facilities.

FM Global via its series of Property Loss Prevention Data Sheets recommends a slightly simpler approach to this subject in which the safe distance should correspond with the maximum width of the fire wall opening, but not less than a distance of 1.8m (see Figure 4).  

 Figure 4. FM Global approach to safe distances from fire doors

Consultation with fire door manufacturers has revealed, not surprisingly, that they do not normally offer advice on the matter of safe distances, instead recommending that the customer refers the matter to their insurers. 

We have no wish to question the merits of either the RISCAuthority of FM Global approaches, which in some respects produce a not dissimilar end result when applied to common size, 240 minute doors and shutters.

When analysing the requirements of spatial separation from uninsulated fire doors and shutters, Consultants should consider the dimensions of the protected opening, the fire resistance rating of the door or shutter and the combustibility/susceptibility of the stored goods and materials, followed by reference to the RISCAuthority and FM Global guidance, subject as a general rule to a minimum distance (rounded up) of 2m from the face of the door or shutter and 1m from the sides.

SURVEY EXPECTATIONS

Where firebreak doors or shutters are encountered in firebreak/compartment walls, every effort should be made to determine their certificated fire-resistance rating under the LPCB, CERTIFIRE or other internationally recognised testing and approvals schemes and, where possible, the status of the installation contractor. Observations should also be made concerning the condition and operation of the doors or shutters, the provision of safe storage zones and enquiries made concerning the arrangements for inspection and maintenance, both externally and in-house.

As regards timber fire doors in key compartment walls such as those enclosing hazardous areas, plant rooms etc., these should also be individually assessed to determine their fire-resistance rating, correct operation and general condition.

For other numerous timber fire doors spread throughout the premises, a random sample inspection should be conducted and enquires undertaken regarding any inspection and maintenance regimes in place, which for large or complex buildings should be recorded in the form of a fire door register.  Whilst the responsibilities for the inspection, servicing and maintenance of fire safety hardware and systems such as fire extinguishers and fire alarm installations are commonly recognised, experience reveals that fire doors are often inadvertently disregarded.   

All defects relating to fire doors should be addressed by risk improvements as appropriate.

FURTHER REFERENCE

Consultants requiring further information on timber fire doors should refer to the BWF-CERTIFIRE (Fire Door Alliance) Fire Doors and Doorsets Best Practice Guide, which is posted in ATLAS. There is also numerous other technical publications available on the BWF Fire Door Alliance website -  https://firedoors.bwf.org.uk/