Fire doors on flats

[JC100]

The building in question was built in 1977 and has small shops at ground floor level and flats on the 1st and 2nd floor (6 per floor), with access off open balconies. There is the main staircase enclosure at one end of the building, this travels from the ground floor to each of the floors above. There are also some stairs joining the 2 balconies together towards the far end. The residents who use these stairs still need to walk across balconies to get to the main staircase to get back to ground level.

 Is this acceptable as a fire exit giving the residents 2 exits, or can it just be classed as an alternate staircase?

The reason i ask is that BS 5588-1 states that only flats with balcony / deck approach accessable by 1 stair are required to have fire doors to FD20 with glazing permitted above 1.1m. This to me says that if 2 staircases are available, fire doors on flats are not required.

 All the flat doors are currently not fire rated (white PVC, double glazed). I think they need to be FD20 as the 2nd stair available doesn't lead to ground floor level.

What do you think?

[nearlythere]

The building in question was built in 1977 and has small shops at ground floor level and flats on the 1st and 2nd floor (6 per floor), with access off open balconies. There is the main staircase enclosure at one end of the building, this travels from the ground floor to each of the floors above. There are also some stairs joining the 2 balconies together towards the far end. The residents who use these stairs still need to walk across balconies to get to the main staircase to get back to ground level.

 Is this acceptable as a fire exit giving the residents 2 exits, or can it just be classed as an alternate staircase?

The reason i ask is that BS 5588-1 states that only flats with balcony / deck approach accessable by 1 stair are required to have fire doors to FD20 with glazing permitted above 1.1m. This to me says that if 2 staircases are available, fire doors on flats are not required.

 All the flat doors are currently not fire rated (white PVC, double glazed). I think they need to be FD20 as the 2nd stair available doesn't lead to ground floor level.

What do you think?

If you have any dead end conditions, even external, you have to provide a protected route. I would be inclined to suggest that if someone has to pass within 1.8M of an opening then it should be protected.
If you don't have a dead end then it doesn't normally require protecting.

[JC100]

So in this case you think using the stairs between balconies is acceptable as it takes away the dead end aspect for most of the flats? a few would still need fire doors because of the dead end. This means that if a fire occured in a 1st floor flat other residents who might need to leave the building would have to use the staircase to go to 2nd floor and pass over the affected flat to exit the building, i'm finding this hard to get my head around.

[nearlythere]

So in this case you think using the staircase between balconies is acceptable as it takes away the dead end aspect for most of the flats, a few would still need fire doors because of this? This means that if a fire occured in a 1st floor flat other residents who might need to leave the building would have to use the staircase to go to 2nd floor and pass over the affected flat to exit the building, i'm finding this hard to get my head around.

The general rule smokescreen is that external escape routes should normally be protected from exposure from a fire eminating from another part of the building for obvious reasons. This is usually done by ensuring that any opening, glazed elements or walls/partitions within 1.8M to the side or above or 9M below is 1/2 FR. There is also some restrictions on uninsulated glazing due to radiated heat effecting the escape route.
If you consider that there are situations where there is only one escape route option and it is within the 1.8M & 9M to an opening rule then you should consider upgrading the escape route. It is normally assumed that there is ony one fire in a building when planning the means of escape.
If you have an suitable alternative means of escape which is readily available then you could consider that no protection is neccessary.
I think I can visualise your layout and if I am right if you can't get to the main staircase because thre is a fire coming out of a doorway you can turn your back and use the balcony stairway to go down to the next level and then gain access to the main stairway from that level.
If so the problem here, as you rightly point out, is that if the fire is in the first floor flat you have to go towards the balony stairway, go up to the 2nd floor to gain access to the main stairway from that level, you still have to pass over the fire.
Have I got the design correct?
How wide is the balcony?
What is the construction of the balcony walls?
How high are the walls?
Are they imperforate as far as they go up?
Is there a stay put option available?

[JC100]

Thanks for your replies nearlythere, that layout you visualise is exactly right.
The balconies are around 1.2m wide. The balcony walls are about 1.2m in height and is split into 3m long sections of brick then obscured georgian wired glass panels in metal frames then back to brick and so on for the full length of the balcony.
Construction between the flats is good so stay put is available.

What you mention about upgrading glazed elements/walls/partitions 1.8m to the side and 9m below, i thought this was only applicable to external staircases where the door enters directly onto the stair and the stair is next to the building (the type used only for escape purposes), the one in question is off the walkway for use at all times so i don't think this will apply.

[nearlythere]

I think because residents can "stay put" it could be reasonable to accept the layout.  Additional to that is the construction of the balcony in that it seems to be of FR construction and if push came to shove occupiers, who might prefer to leave the building, can do so albeit by crawling along the balcony to the main stairway. If they are unable to do so they could return to their flat or flats where they could have stayed put anyway, providing the building is of stay put construction.
Thats my thinking but maybe someone else might have a view.

[nearlythere]

Thanks for your replies nearlythere, that layout you visualise is exactly right.
The balconies are around 1.2m wide. The balcony walls are about 1.2m in height and is split into 3m long sections of brick then obscured georgian wired glass panels in metal frames then back to brick and so on for the full length of the balcony.
Construction between the flats is good so stay put is available.

What you mention about upgrading glazed elements/walls/partitions 1.8m to the side and 9m below, i thought this was only applicable to external staircases where the door enters directly onto the stair and the stair is next to the building (the type used only for escape purposes), the one in question is off the walkway for use at all times so i don't think this will apply.

The means of escape from a building is to a place of safety and not just to outside the building as was in the past. People can still be exposed to danger until they are away from the building.

[JC100]

What distance would you call 'a safe distance' from a residential building? The height of the building horizontally? And obviously taking surrounding hazards into account. Wouldn't want people getting run over etc as soon as they get out of a building safely!

[nearlythere]

What distance would you call 'a safe distance' from a residential building? The height of the building horizontally? And obviously taking surrounding hazards into account. Wouldn't want people getting run over etc as soon as they get out of a building safely!

It is not so much distance as being no longer in a position to be exposed to a risk from fire in the building and that is what you have to assess.
You can evacuate a building to outside the front or back door but still be exposed to a fire eminating from a opening onto your external escape route. This is particularily hazardous with large numbers of people where some further back in the crowd cannot see that the ones in front cannot proceed past the final door as the route is effected by a fire. The people in front want back in and those further back want to go forward to get out. Those towards the front could ultimately be pushed towards the fire by those behind who are unaware of the situation.

[Davo]

Correct me if I'm wrong but didn't I read somewhere safe distance is AS A MINIMUM one and a half times the height of the building.
Other factors to be considered could be risk of explosion, ferocity, wind direction etc etc, FRS know better than me
Plus the need to get out of the way of the shiney red thing!

davo

[nearlythere]

Correct me if I'm wrong but didn't I read somewhere safe distance is AS A MINIMUM one and a half times the height of the building.davo

Possibly Davo if the building was going a dinger from end to end and top to bottom. We haven't gone that far yet. All we are doing is getting out of a block of flats where one of them is on fire.

[wee brian]

The one and a half thing is a recomendation for houses. It would be daft to apply it to a block of flats

[Tom Sutton]

The means of escape from a building is to a place of safety and not just to outside the building as was in the past. People can still be exposed to danger until they are away from the building.

circ 1974 Moreton in Marsh notes

8.5. Stage 4 Travel - Final Escape at Ground Level

Stage 4 travel is from the foot of the staircase to the outside. The stairs should not all converge into one common area at ground level; otherwise a single incident can simultaneously block all routes. Although this might appear obvious when stated here, there have been a number of examples of buildings where protected routes from upper floors discharge into a common central atrium.

It should not be forgotten that the final exit and external design of a building also have to be considered in escape planning. It must be possible to leave the building and to get a safe distance away. There is a need to take account of the number of people that may escape from a building and their need for a readily identifiable assembly point or transfer area. Where large numbers of people may be involved, it will be necessary to plan these areas, so there is no conflict of use as the emergency services arrive and begin to fight the fire.