Fire door requirements for flat entrance doors in pre-1991 converted flats and purpose-built flats

[IanMP]

I have been researching fire doors and find the guidance a little difficult to pin down for converted flats. 

It seems more black and white for purpose built flats as it is clearly outlined in the guidance, even then some assessors and fire door surveyors would recommend upgrading all doors with intumescent and smoke seals where the guidance suggests it is acceptable to retain notional FD30 without upgrades providing they self close, fit suitably in their frames and remain in good condition.

Lacors suggests in all cases flat entrance doors that open onto the escape route should be FD30S, I assume this also includes upgraded FD30S, but this is not mentioned.

There is a bit of conflict in the Lacors guidance, where Figure 10, referred to below in the case study, clearly shows FD30 doors.

Case study D10: Two-storey building converted 
into self-contained flats (see figure 10)

Escape routes (see paragraph 9)
30-minute protected route is required, including 
30-minute fire-resisting construction and FD30S doors 
to rooms opening onto escape route. No requirement 
for fire doors within flats, but sound, well constructed 
and close-fitting conventional doors are required. 
Travel distance must not be excessive

It may be possible to accept an existing lower standard 
of protection in the protected route if there are 
suitable escape windows from bedrooms and living 
rooms (see paragraph 14) 

 

In Case study D11: Three- or four-storey building converted into self-contained flats (see figure D11) the guidance says

FD30S doors to rooms opening onto escape route. No requirement 
for fire doors within flats, but sound, well constructed 
and close-fitting conventional doors are required.

BUT in figure D11 it says "30 minute FD30S fir doors to each flat entrance and ideally to rooms within flats". 

 

I have four questions:

1. Has anyone seen, or recommended, FD30S doors to be installed to rooms within flats?

2. Is an upgrade to FD30S the correct recommendation for all flat entrance doors, converted and purpose-built, regardless of where the government guidance says it is not necessary?

3. I have also read fire risk assessments, and seen fire safety advice on company websites, that suggest an 8mm or 10mm gap at the bottom of an upgraded FD30S door, but I read this as <4mm without a threshold seal or <3mm with a drop seal.  Which is the correct line?

4. I know advice can change with risk assessment, but Is there a definitive guide on fire doors in converted flats?  Or a summary that pulls together all of the guidance for converted flats and purpose built flats?

This has been discussed before and I have read almost all of the previous posts without forming a clear idea of what would satisfy any enforcing authority.

Ian

[AnthonyB]

I have four questions:

1. Has anyone seen, or recommended, FD30S doors to be installed to rooms within flats? No, the requirement where a flat was built to Building Regulations has never been FD30s, originally it was fire check doors, then FD20 doors and currently FD30 doors. 

2. Is an upgrade to FD30S the correct recommendation for all flat entrance doors, converted and purpose-built, regardless of where the government guidance says it is not necessary? It's not necessary or proportionate, the guidance was written to balance adequate safety with not burdening home owners with excessive costs (from £800-£3000)

3. I have also read fire risk assessments, and seen fire safety advice on company websites, that suggest an 8mm or 10mm gap at the bottom of an upgraded FD30S door, but I read this as <4mm without a threshold seal or <3mm with a drop seal.  Which is the correct line? One for our resident fire door expert Neil, but if it's upgraded to achieve a notional FD30S I would expect that to include the threshold gap using a drop down seal or hardwood lipping

4. I know advice can change with risk assessment, but Is there a definitive guide on fire doors in converted flats?  Or a summary that pulls together all of the guidance for converted flats and purpose built flats? A replacement for the LACORS guide is under preparation (& has been since about 2019, but was in hiatus for several years) and is by the authors of the Purpose Built Flats guide so will be in the same vein and use the same principles and thus not be as conflicting

This has been discussed before and I have read almost all of the previous posts without forming a clear idea of what would satisfy any enforcing authority. The guides have status under Article 50 of the Fire Safety Order such that following them would see a premises 'deem to satisfy' the requirements of the legislation as long as correctly applied for a particular scenario

[Neil ashdown]

3. I have also read fire risk assessments, and seen fire safety advice on company websites, that suggest an 8mm or 10mm gap at the bottom of an upgraded FD30S door, but I read this as <4mm without a threshold seal or <3mm with a drop seal.  Which is the correct line? One for our resident fire door expert Neil, but if it's upgraded to achieve a notional FD30S I would expect that to include the threshold gap using a drop down seal or hardwood lipping.

'BS 8214: 2016 Timber-based Fire Door Assemblies - Code of Practice' is widely referenced with regard to the threshold gap of a fire resisting door in the closed position.  In terms of a fire door, the maximum gap should be as stated by the door leaf manufacturers certification data sheet. Generally this is between 6mm and 10mm maximum. Think of this gap in terms of limiting the drawing of cold air under the door to feed the fire and limiting the amount by which door may drop should the hinges fail to support the door as the fire has an effect on the condition of the door.  Doors that are required to restrict the spread of cold smoke should have a maximum gap of 3mm at the threshold. Where such a tight gap is not achievable, the gap should be sealed with a flexible strip.