Smoke seals

[Meady]

Hi

Do all fire doors in commercial premises need to have smoke seals fitted?  in this case, an office accommodation.

The query has been raised that, whilst fire doors along means of escape such as stairways and protected corridors have fire strips (intumescent) and smoke brushes, doors to store rooms, boiler cupboards, electrical equipment housing in accommodation areas have only fire/intumescent strips.  

Third party Fire Risk Assessor has said that all fire doors must have both intumescent strips and smoke seals/brushes.  But, a third party fire consultant has said that this is not the case - reason being that, in an office accommodation, there is not any requirement for fire detection in these cupboards.  So, the doors need to allow a small amount of smoke to escape so that occupants can see and raise the alarm (which to me makes sense).  But the FRA doesn't explain why all doors need smoke seals - appears to be a generic action perhaps?

I have been looking at ADB Vol 2, Table C1 but this is obviously for brand new buildings and not one like ours which is 1970(ish).  We had the smoke seals retrospectively fitted to the doors along escape routes about 5 years ago as this made perfect sense to avoid smoke spreading to the stairs and corridors - but is there a change of standard that says all doors now have to have smoke seals?

As always, any guidance always appreciated.  

[AnthonyB]

For any door protecting an escape route the benchmark is an FD30s door (intumescent seals and cold smoke brush/fin) - this is also in the guidance for existing premises. For a door only enclosing an area of special fire risk the benchmark is FD30 or in some cases FD60 (seals but no smoke brush/fin).

The letting some smoke through is a bit of an outdated principle only remaining in the LACORS housing guidance (which is being reviewed as it's shockingly outdated)

A building from the 60's/70's will have required fire doors in order to get a Means of Escape Certificate under the Offices, Shops & Railway Premises Act 1963 (later a fire certificate under the Fire Precautions Act 1971) but back then the technology of intumescent seals didn't exist and so to prevent leakage the doors had to close fit in a frame fitted with a 1" (25mm) rebate. It didn't work that well (but was an improvement on what went before) and created other issues (the door edges would char and produce a heavy tarry smoke that wouldn't reach ceiling height in the adjacent area and so miss smoke detectors for a period of time (this is why the provision of detection in rooms opening onto escape routes was introduced in the 80's to solve the issue of fires in hotel bedrooms that did not activate detection in the corridor, which was all that was usually present if at all).

Proper risk assessment, in line with the accepted methodology PAS79-1 & 2 does not reject legacy provisions out of hand and simply examines the differences between old and new and if that difference creates an intolerable risk. In an office with legacy rebate only 30 minute fire door, where there is no sleeping risk, no delayed evacuation, occupiers familiar with the premises, ideally 2 exit routes and a higher than normal fire protection package (essentially any meaningful detection provision as the minimum for offices is still call points only) it is not unreasonable to accept the doors, noting that upon damage, replacement or a building refurb they should then be replaced.

 

[Meady]

18 hours ago, AnthonyB said:

For any door protecting an escape route the benchmark is an FD30s door (intumescent seals and cold smoke brush/fin) - this is also in the guidance for existing premises. For a door only enclosing an area of special fire risk the benchmark is FD30 or in some cases FD60 (seals but no smoke brush/fin).

The letting some smoke through is a bit of an outdated principle only remaining in the LACORS housing guidance (which is being reviewed as it's shockingly outdated)

Hi AnthonyB - as always, thank you for such a great, comprehensive answer.

So, same question but in a block of flats, would you expect cupboards within stairways used for means of escape to be FD30/60s or just FD30/60?  I am just thinking of a block where I know the doors to flats and stairs are FD30s but the cupboards to electrical meters and risers are FD30 with no smoke seal/brush (just fire strip).  Would this be better to have FD30s on cupboards?  How would a fire in the cupboards be detected in early stages if smoke seals fitted?  Also, in some flats (more modern) they may have automatic detection in stairs to actuate AOV's... would you then recommend auto detection in the risers?

[AnthonyB]

Smoke seals would protect the escape route and a well sealed cupboard will have limited growth in this situation as there would be limited oxygen (& limited materials) to cause spread - better to contain it - it may even go out.

Depending on the design category of the system & the strategy there may be detection in the riser shaft or cupboards, a typical stay put wouldn't always have them for the shafts/cupboards just the main room, but there are no hard and fast rules, you see it done differently all the time and as long as the minimum expectations are met it's OK

The revised LGA Guide will hopefully deal with this and as it is planned to have special status (failure to follow it would be evidence in it's own right of an offence whereas at the moment it's just a benchmark to judge against) will be the one to follow closely.

[Meady]

That's great - thank you AnthonyB! ?

[Guest Nikki U]

Hi 

Had an inspection for Landlord accreditation that states  “door frames separating the bedrooms from hallway are of FD30 type, which (without fire detection both sides of the door) might delay activation of the smoke alert. This may lead  to a fire progressing undetected in the bedrooms.”.

The action required replace the current intumescent strips that incorporate cold smoke seals located in bedroom fire door frames with intumescent strips that do not incl a cold smoke seal . this is to enable smoke from a fire to reach and activate the fire detection in the shortest possible time “

 

I thought the point was to give more time to anyone sleeping/ in a bedroom to reduce smoke ingress ?

any advice appreciated.

 

[Neil Ashdown MAFDI]

You don't say whether the bedrooms open on to a communal area or are located within a flat? 

Usually bedroom doors inside a flat will be FD20 and not have smoke seals fitted (unless its a large flat) whereas bedroom doors that open onto communal areas will be FD30(s) with smoke seals fitted to restrict smoke logging in the corridor/hallway to provide for safe escape.

Furthermore, perimeter smoke seals fitted to doors will not completely stop smoke spread (only restrict it) because leakage will take place at the hinges and lock positions and under the door. 

Clearly, additional fire detection would improve the situation but in any event you would be advised to speak with the inspector in detail for clarification about how best to provide the safest solution. 

[AnthonyB]

They are using the obsolescent LACORS Fire Safety Guide which has this view. The guide is being rewritten at the moment and it will be interesting to see if this approach is retained.

Bear in mind though that a new build house or flat in England with a protected stair or hall with only detection in the escape route (or best escape route, kitchen and living room) would only require internal FD30 doors (no smoke brush/fin) so the principle isn't just confined to the older HMO guidance.