Neil ashdown

The regulations in terms of access and use of buildings is https://www.planningportal.co.uk/info/200135/approved_documents/80/part_m_-_access_to_and_use_of_buildings I would advise you to check with local authority building control as to whether your proposal is in scope of Part M requirements for dwelling houses. There are limits to how narrow a fire door leaf can be in terms of its fire resistance performance but as you haven't said how narrow the door would be, I cannot comment further.

Assuming the fire doors are wooden ones. Strip and paint them as you would any wooden door. Do not paint over smoke seals and avoid adding metallic facings.

This one is interesting because when timber-based doors are tested for fire resistance performance it is assumed that the door would be positioned at floor level. In fact the fire tests used in the UK are BS476 part 22 & EN1634-1 and both tests place a pressure at a certain height on the door from the furnace side, see below. However, the tests are a 'benchmark' and, as your scenario demonstrates, not always reflective of the use of the door in real life. Therefore it should be borne in mind that the fire resistance of the door in your end use may be different to its 'as tested' performance. Furthermore, the fire in a real life situation may be different in its character to the one in the BS/EN test furnace. Where you have any concerns, it would be best to discuss them with an expert in fire doors.

This should be helpful: And this:

Government guidance can be found here https://www.gov.uk/government/publications/building-safety-advice-for-building-owners-including-fire-doors at page 29 and annexe A

Usually a flat entrance door that opens onto an outside area would not need to be fire resisting. However, there are some occasions where one would be necessary, such an example could be that there is a balcony / escape route above or adjacent to your door. If in doubt check with an expert.

To be certain you will need to check with the fire door manufacturer. The door could be composite construction or it could be solid timber? The knocker could be faced-fixed or it could be bolt through?

BS 8214:2016 Timber based fire door assemblies- Code of practice. Paragraph 9.5.2 deals with operating gaps "A typical gap to achieve good fire performance is between 2mm and 4mm".

A fire door must self-close all the way to the rebate stop. Contact an independent fire door inspector for advice. Fire door inspectors are listed at: https://fdis.co.uk/find-an-inspector-2/ and https://www.blueskycert.com/members-main/#fire

It would be advisable to consult a certificated fire door inspector to undertake on-site inspections to assess the suitability and condition of the existing fire doors. They should issue a full report detailing the doors and describing any necessary remedial actions. Avoid inspectors that do not provide sufficiently detailed reports. Much better to get a report that provides a full description of the work necessary to achieve compliance. Fire door inspectors are listed at: https://fdis.co.uk/find-an-inspector-2/ and https://www.blueskycert.com/members-main/#fire

It would be advisable to consult a certificated fire door inspector to undertake on-site inspections to assess the suitability and condition of the existing fire doors. They should issue a full report detailing the doors and describing any necessary remedial actions. Avoid inspectors that do not provide sufficiently detailed reports. Much better to get a report that provides a full description of the work necessary to achieve compliance. Fire door inspectors are listed at: https://fdis.co.uk/find-an-inspector-2/ and https://www.blueskycert.com/members-main/#fire

When repairing fire doors, fitting a hardwood lipping can be an effective method to repair a damaged edge or to achieve compliant door leaf to door frame gaps. However, it is likely that such repairs would affect the manufacturer's certification for the fire door. Can the manufacturer be identified so as to try and retain fire resistance performance certification, or is the manufacturer unknown? If unknown, can the door's fire rating be confirmed? Important considerations include: use of suitable adhesives, timber density and dimensions and of course the quality of the work. It would be advisable to undertake suitable fire door training and/or consult a specialist when undertaking these types of repairs.

From what you say it seems that the door is a flat entrance door. In which case the door should resist fire spread for at least 30 minutes and also restrict the spread of cold smoke. The Standard for installation of timber-based fire doors is 'BS 8214:2016 Timber-based fire door assemblies - Code of practice'. The Standard states that the gap between the bottom edge of the door leaf and the floor, in the door-closed position, should be 3mm. To resolve an issue where the gap is too large, the most effective method is to fit a threshold plate to the floor.

The fire risk assessment for the school should be clear about where fire doors are necessary. It would be expected that a school built to regulations in 1999 would have fire doors installed at the fire safety critical locations. Looking at risk from fire at the school, does the classroom need to be a fire compartment?

Doors are sometimes clad with fire rated boards to improve fire resistance performance. However where fire resistance is required, the board used would usually be cement based rather than timber based.

If the door is a fire door and you make alterations to the door and/or fit glazing, you must make sure the door leaf is suitable to have an aperture cut and that the glazing is suitably fire rated and installed correctly. The issue is that in a fire situation the door, if not correctly glazed and installed, could fail to sufficiently resist the spread of fire. If in any doubt consult a certificated fire door inspector for advice.

If the door is a fire door and you make alterations to the door and/or fit glazing, you must make sure the door leaf is suitable to have an aperture cut and that the glazing is suitably fire rated and installed correctly. The issue is that in a fire situation the door, if not correctly glazed and installed, could fail to sufficiently resist the spread of fire. If in any doubt consult a certificated fire door inspector for advice.

Annexe C (Fire Doors) at Building Regulations Approved Document B https://www.gov.uk/government/publications/fire-safety-approved-document-b

You will need to read the installation instructions for the particular fire door leaf to find out what hinge type, size and fixing positions are necessary. As they are new doors, the door leaf supplier/manufacturer is obliged to provide installation instructions.

Be careful about generalisation with regard to timber-based fire door installation requirements. The image below is an example of intumescent gasket requirements for hinges for an FD30 timber-based fire door:

Fire fire doors, with regard to restricted smoke spread the excerpt above is from building regulations in England & Wales Approved Document B, Table C1. Looking at 2a it can be seen that smoke leakage is allowed but not exceeding the stated rate, from the head and jambs only. There is no mention of the threshold gap. Section 12.3 at BS 8214:2016 provide specific guidance about the gap at the threshold and the following information from www.ifsa.org.uk may be useful: "Because it is perceived to be difficult to achieve a seal at the threshold, the gap at the bottom of the door is exempted from the leakage criterion in Approved Document B. As the gap at the bottom of the door is straight through and is invariably wider than elsewhere in the assembly, then if the smoke is truly mixed and at an even pressure and temperature, a greater proportion of the smoke is likely to be egressing from this gap than any of the others. The pragmatic decision to ignore the leakage from the bottom assumes that there will be some stratification of the gases and, therefore, less polluted air will be present nearer to the floor level. This cannot be guaranteed and so leakage through the threshold gap would lead to rapid smoke logging of the protected space. There are, therefore, real benefits to be achieved if the threshold is sealed to satisfy similar levels of performance. This is something that has been recognised in BS 9999 and BS 9991, where it is recommended that for an adequately smoke sealed door the threshold is sealed with a drop down seal, or one that makes continuous contact with the floor, or where this not practicable that the gap at the bottom of the door is controlled to 3mm".

This type of self-closing device is installed into mortice holes in the top edge of the door leaf and door frame head. The arm is connected at the device and at the door frame head. The top edge of the door is partially scalloped to accommodate the arm. It is important to understand that only specific timber-based fire doors are suitable for this type of self closer, they must have evidence of fire resistance performance when fitted with the particular self-closing device. Furthermore, certain additional works will likely be required such as thicker hardwood lipping at the door leaf top edge, increased thickness of the door frame head and the use of intumescent gaskets to line the mortice work. Where the door must restrict the spread of cold smoke it will be necessary to ensure that the smoke seal continues past the device. The device should always come with installation instructions and documentary evidence of fire performance.

I expect you mean an intumescent air transfer grille? These do not restrict the spread of cold-smoke, so only where the fire risk assessment allows.

For this type of door, the maximum threshold gap should be 3mm because building regulations require the fire resisting doors in common areas of blocks of flats to provide restricted spread of cold smoke. Refer to BS 8214:2016 Timber-based fire door assemblies - Code of practice, section 12.3. The use of a suitable threshold plate will certainly make it much easier to achieve this gap and Building Regulations Part M compliant ones are available. However, if a hazard assessment has ruled them out it will be necessary to fix a hardwood lipping to the door leaf bottom edge and/or fit a drop-down or static threshold seal. Survey each door to see which remedy is most suitable for the particular door. Whether or not a timber-based fire door leaf may be fitted with a hardwood lipping will depend on the construction type of that particular fire door and possibly whether the original installer over-trimmed the door leaf when they fitted it. When resolving edge and threshold gap issues, it is sometimes necessary to remove the complete door and frame assembly and re-install to the correct tolerances. The gap between the door frame and the surrounding wall substrate should be within the scope of the requirements set out in the document BS 8214:2016 Timber-based fire door assemblies - Code of practice, section 9.

For a double-swing-action timber-based fire door it will be necessary to use pivots instead of hinges. It will likely be necessary to use a floor=spring instead of an overhead self-closing device. Not all timber-based fire doors will be suitable for this application, so consult a specialist fire door supplier/manufacturer. And follow the installation instructions for that particular door leaf.