Common Escape Routes

[GregC]

Typically in infants schools the classrooms have external doors for the children to use at playtimes etc, with even a manual system these doors need to be covered by manual call points.

When a L4 system is specified do the classrooms become "any other part of the Common Escape Routes"?

If I were in a corridor and the fire alarm activated the exit signs would not normally lead me through a class room but via a dedicated exit, so I would argue they do not, however they are part of the escape route for the classroom so I could argue they are.

Where a classroom is larger than a single detector would provide cover for, would a detector adjacent to the external door be compliant for L4 recommendations?

[Wiz]

Good question Greg C, and one that I have also previously pondered!

Obviously, if every exit door in a classroom to the open air is considered a proper escape route for persons anywhere in the building, then in an L4 system, automatic detection would also  be required in the classroom. And if the classroom is big, then more than one might be required.

My previous pondering has led me to the following conclusion (rightly or wrongly!);

The classroom is not part of the common escape route unless signage from the corridor/circulation area indicates that the route is an emergency exit.

In my view, the exit doors to the open air from classrooms are primarily planned for the use only of those persons in that classroom i.e so they don't need to enter the corridor in an emergency situation (especially where they can't in an emergency). These classroom doors invariably do not have any proper emergency exit door hardware or, are normally not as wide as proper emergency exit doors. This is probably why signage doesn't normally direct persons in a corridor/circulation area to use a route through a classroom as a means of emergency exit.

If my conclusion is right, then no detection is required in the classroom for an L4 system unless signage outside the room indicates that the route through the classroom is an emergency exit route.

The second part of your question I believe could be argued as being fully answered by the recommendations of BS which allows no variation in the amount of detection required in any area i.e. if it has to have detection the recommendations for detection quantity/spacing etc. always apply.

However, Lord Toddy always insists that system designers should be brave and use their knowledge, experience and commonsense in most situations and not always slavishly follow a BS recommendation when it's application in a certain situation seems to be 'over the top'

Applying this argument to your specific question, if you had a room that was, say, 6m wide and 50m long (silly dimensions I accept!) and you had an exit route that crossed the width only and totally at one end of the room, and you decided to cover this route with automatic detection in a L4 system then surely one detector only at the end of the room with the exit route would be sufficient to detect the amount of smoke that might affect the safe use of that exit route? A 'codehugger' certainly wouldn't agree with this argument but I see this being an example of Mr Todd's suggested way of looking at some things.

To further support both the above conclusions, I would argue that providing automatic smoke detection doesn't actually stop anyone from trying to use an exit route that is affected by smoke in that area. People could still take a route that led them to where the smoke exists! The detection in an L4 system is installed to provide an early warning that there is sufficient smoke somewhere on an exit route to operate a detector, and that if immediate evacuation is not commenced these routes may become filled with enough smoke to eventually prevent their use as a means of escape.

[Midland Retty]

It would be totally over the top to install MCPs adjacent to each classroom door leading to fresh air. I do not believe that classrooms could be thought of as "part of common escape routes".

Looking at it logically if there were a fire in the classroom, and the teacher immediately evacuated the children via the door leading to fresh air,  then the alarm wouldnt be raised manually (due to no MCP being present)

But a procedure could be implemented whereby a classroom assistant, for example, is dispastched to activate the nearest MCP whilst teacher marshalls the children at the assembly point.

Would it be appropriate to expect that the smoke detector in the room will activate and that manual intervention would not be required subject to suitable risk assessment???.

Im not saying these are ideal answers but my point simply is that there are several scenarios where a managed solution could negate the need for MCPs to be fitted everywhere.

As regards the siting of detectors, as Wiz points out common sense should prevail and I agree with the logic given in his reply.

[GregC]

20.2 c is quite specific and leaves no room for argument in my opinion

[nearlythere]

These classroom doors invariably do not have any proper emergency exit door hardware or, are normally not as wide as proper emergency exit doors.

Where do you pick this up from Wiz?

I can understand the issue with call points at all exits even if they are not indicated escape routes. They are still a means of leaving the building and can be used as such in an emergency.

[Wiz]

It would be totally over the top to install MCPs adjacent to each classroom door leading to fresh air. .................

M.R. I agree with Greg C that there is no way that mcps shouldn't be installed to all exits to the open air.

The current B.S. recommends it. It was an upgrading from the previous B.S. that previously only recommended needing them at fire exits. It has also now become common practice in design and install to have one at every door to the open air and it has meant that many schools have an enormous number of mcps installed because there is often a door leading to outside from all ground floor classrooms in modern buildings.



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[Wiz]

These classroom doors invariably do not have any proper emergency exit door hardware or, are normally not as wide as proper emergency exit doors.

Where do you pick this up from Wiz?

I can understand the issue with call points at all exits even if they are not indicated escape routes. They are still a means of leaving the building and can be used as such in an emergency.

Nearlythere, I picked this up from observation of such doors with my very own eyes!

We are talking about doors leading to the outside from rooms. The understanding by gregC, myself and many others is that B.S. 5839 recommends mcps always at such doors. We install them even if exit through this door is not normally easily available (i.e. it might be locked!)

Such doors are normally only single leaf and have just a simple lever handle, not crash bars or maglocks etc. etc. And sometimes they might also have a key-operated deadlock and (if lucky) a key in a box nearby (I know, I know!). I'm presuming that many of these doors were originally installed as a convenience rather than a necessity for emergency exit purposes.

The point I am making is that these doors, even when they don't have deadlocks etc., are normally not 'designated' as emergency fire exits i.e there are not any signs in the corridors directing people through the classroom to use these exits, but this doesn't cancel the need for installing an mcp next to them, since the current B.S. recommends that we do.

The previous B.S. mentioned fire exit doors, the current mentions all doors leading to the open air.

Although it might seem silly to put an mcp next to a door that is normally locked and unavailable for use, I presume that B.S. has now decided that there might be occasions when it might be unlocked, and even wide open,  and if someone was to use it in an emergency it is only right that they have the opportunity to raise a fire alarm signal.

[nearlythere]

I have in the recent past, in two situations, not asked for a MCP at a final exit door (sliding patio type) from a common sitting room. This was a residential home and the particular door was very rarely used and was not indicated nor needed as an emergancy exit.  Class 1 AFD throughout so I deemed it excessive and unnecessary.
I think one has to draw a distinction between a fire risk assessment and a code compliance audit.

[nearlythere]

These classroom doors invariably do not have any proper emergency exit door hardware or, are normally not as wide as proper emergency exit doors.

Where do you pick this up from Wiz?

I can understand the issue with call points at all exits even if they are not indicated escape routes. They are still a means of leaving the building and can be used as such in an emergency.

Nearlythere, I picked this up from observation of such doors with my very own eyes!

We are talking about doors leading to the outside from rooms. The understanding by gregC, myself and many others is that B.S. 5839 recommends mcps always at such doors. We install them even if exit through this door is not normally easily available (i.e. it might be locked!)

Such doors are normally only single leaf and have just a simple lever handle, not crash bars or maglocks etc. etc. And sometimes they might also have a key-operated deadlock and (if lucky) a key in a box nearby (I know, I know!). I'm presuming that many of these doors were originally installed as a convenience rather than a necessity for emergency exit purposes.

The point I am making is that these doors, even when they don't have deadlocks etc., are normally not 'designated' as emergency fire exits i.e there are not any signs in the corridors directing people through the classroom to use these exits, but this doesn't cancel the need for installing an mcp next to them, since the current B.S. recommends that we do.

The previous B.S. mentioned fire exit doors, the current mentions all doors leading to the open air.

Although it might seem silly to put an mcp next to a door that is normally locked and unavailable for use, I presume that B.S. has now decided that there might be occasions when it might be unlocked, and even wide open,  and if someone was to use it in an emergency it is only right that they have the opportunity to raise a fire alarm signal.

Don't understand as the original post was from GregC so can't fathom out how you know about the door sizes and hardware.

[Wiz]

Silly me! I have in my possession Lord Toddy's book explaining the rationale behind the B.S. recommendatins.

I have now checked what it says on this subject;

.......Note that, in the case of exits to the open air, these may or may not be designated as fire exits. The reason that the code recommends that manual call points be provided adjacent to all exits that may not actually be designated as fire exits is that, in the event of fire, occupants tend to use the nearest exit, which in the case of, for example, a loading bay, may not actually be designated as a fire exit.    ........

The oracle has spoken and we guessed right!

Whilst this doesn't directly answer GregC's original question I think that, by lateral thinking, it confirms my opinion that detectors are not required in a room of an L4 system if there is a door to the open air from it, unless that door is a designated fire exit.

[GregC]

Anther spanner in the works then, what if the door from the classroom was not indicated as a fire exit from the corridor but had a fire exit sign over the door, this then becomes a nominated exit and require detection even in a L4 system doe sit not?

(looks over shoulder to see where Wiz is spying on me from.....)

[nearlythere]

Anther spanner in the works then, what if the door from the classroom was not indicated as a fire exit from the corridor but had a fire exit sign over the door, this then becomes a nominated exit and require detection even in a L4 system doe sit not?

(looks over shoulder to see where Wiz is spying on me from.....)

Then remove the exit sign if it was only put there to cover up a hole.

[Wiz]

Don't understand as the original post was from GregC so can't fathom out how you know about the door sizes and hardware.

My answer to GregC was to explain why I thought the type of door was relevant to his question about the requuirements for smoke detection.

In my answer I explained that I have also seen such doors and I have also seen that they are often only single leaf and sometimes do not include the sort of hardware expected of a proper fire exit. This indicates that they are probably not a designated fire exit.

I know nothing about the sizes and hardware of any specific doors and also none were mentioned by GregC.

[Midland Retty]

It would be totally over the top to install MCPs adjacent to each classroom door leading to fresh air. .................

M.R. I agree with Greg C that there is no way that mcps shouldn't be installed to all exits to the open air.

Yoo hoo im over here Wiz - I think you meant to say "Greg C I agree with M.R."  do put your glasses on!

Back to your spanner in the works GregC even if the classrom door leading to fresh air had a fire exit sign over it I wouldn't be worried about putting a detector in there. Infact I'd probably recommend the sign is removed!

[Wiz]

Anther spanner in the works then, what if the door from the classroom was not indicated as a fire exit from the corridor but had a fire exit sign over the door, this then becomes a nominated exit and require detection even in a L4 system doe sit not?

(looks over shoulder to see where Wiz is spying on me from.....)

GregC, I can see you clearly from where I am sitting. I don't supply CCTV equipment to others and then not use it myself to spy on them!

To answer your new question; IMO, If the door has an exit sign above it then it should be a designated emergency exit, have all the correct hardware/locking devices/safety equipment fitted, be the right size etc. but then you would also need to fit a detector in the room for an L4 system cos' it would be part of the exit route!