Corridor sub-division in schools

[Golden]

I have had a request from a school to alter a recommendation that I made on a recent FRA. The simple explanation of the issue is a corridor (95Metres) that is currently not sub-divided, school is four storeys and this situation occurs on the upper three floors, means of escape alternatives/widths/distance are fine and the school is well managed and fitted with AFD L3+. The corridors have classrooms off of one side only - the other being glazed to the outside. The building is listed being built in the 1930s, and is fitted with crittal doors protecting the staircases (OK I know but that is one of the major reasons for the listing!). I recommended corridor subdivision to comply with guidance but also to give some good compartments and take the reliance on the crittal doors out of the equation.

My problem now is that the school want to enclose every room onto the corridors in 30 minute FR and not do the subdivision because of heritage issues and pupil movement around the school, magnetic holders were to be fitted. I want to stick to my original recommendation and insist on the corridor subdivision - but I can't really explain why!! The enclosure of the rooms will surely make the building safer by reducing the sub compartments but there is still a gut feeling that this won't be right - any thoughts?

[kurnal]

Why do we subdivide corridors? To ensure a fire and smoke cannot simultaneously affect both exits from it. If they enclose rooms that open onto the corridors (assuming they are not high risk rooms) are they achieving the same objective in a different way?  It could be that they are but only if discipline is good, clearly some smoke will enter the corridor as persons evacuate the room involved in fire but people in occupied rooms tend to discover fires in their very early stages!

The biggest risk might be a fire in an unoccupied room witht he door wedged open. It could work for me with discipline and perhaps detection in rooms likely to be unoccupied.

[Midland Retty]

My view, given the historical importance of the building, and the fact that a school is an important community resource, would be to continue pushing for sub compartmentation, with hold open devices to allow circulation for pupils.

This would compensate for any management issues in terms of maintaining the means of escape (the propped fire door scenario Kurnal mentions above) and would offer enhanced levels of property protection.

The school needs to carefully consider the impact a fire could have on its ability to continue with its function, and the knock effect it could have for the community, and dare I say it, the tax payer.

[Golden]

Just to clarify a couple of points. The school security is such that access to all of the classrooms is by key card therefore they are not in my experience wedged or left open at this premises. Most of the rooms off of the corridor are normal classroom risk, most are protected by AFD and the school benefits from high ceilings - about 4.5m high in the affected areas. I was thinking of a half-way measure of asking for some smoke screens but wondered if they would give any real benefit as we'd be talking about cooler smoke emanating from any closed doors?

Thanks for your comments as they have helped clarify my thinking on the subject. Unfortunately I was being a bit indecisive as initially I was thinking along the same lines as Kurnal but was stepping back to where midland is coming from - I've now arranged to meet the local fire officer at the premises in a few weeks time so will let you know what he thinks.

[Phoenix]

Here's a few points that come to mind.

Corridors in schools are often what used to be called 'dual purpose' areas, i.e. they are circulation spaces and also areas to display students' works of art and to install mini library extensions (no coat racks though, no no no).  Are these corridors so used?  May they be in the future?  It would make a big difference.

English Heritage or other bodies involved in listing buildings usually have no problem, even for the Grade 1 buildings - and I doubt this building is Grade 1, in accepting fire resisting screens and doors that cause virtually no damage to the existing structure (such as a few screw holes) and which are completely removable.  Any such doors should, of course, be held open on magnets as previously suggested otherwise they are likely to be destroyed in a short space of time.

Subdividing corridor doors serve a couple of functions that might be important if there are (often, to be expected) fire safety failures in the future.  They reduce the chances of both staircases being lost to a single fire - the required fire safety failure here would be doors to staircases wedged open or damaged (not unknown).  They also reduce the distance that anyone might have to travel through an unprotected corridor that is affected by smoke from a fire in an adjoining room; and there is no requirement for a fire safety failure here. 

The enclosure of each classroom probably will compensate for both of these functions, provided that the corridor is free of any fire load, but it won't future-proof the building against the introduction of fire loading into the corridors.  And it will also be a lot more expensive!

Dividing a school into many small compartments might have benefits for protecting property, which is very important in schools, but it sounds like an unusual solution.

This sounds like my old school, it's not in Cotham, is it?

Stu

 

[Davo]

Golden


Even if the school fits fire doors to the classrooms,how solid are the the compy walls?
Did you examine all 95m X 4?
Can you guarantee the school IT bloke won't hack some out to stuff his cable through?
I saw one place where out IT contractors must have used a sledgehammer for their tiny cable


Are the staircases at each end or also in the middle?
What about detection?

davo

[Golden]

Hi Davo, yes there is a bit of work to be done on the walls and some non-fr glazing but in general the walls are solid brick and the floors are solid concrete - its about as robust a construction as you could encounter to be honest! Staircases are either end and one central. Stu, the  corridors are sterile, not even a poster on the walls (unusually) but its the school that wants to protect in this way. I would prefer the subdivision but they have asked the question and I feel obliged to explore all options and don't want to just give the code hugger answer!!

Its not Cotham but I'm sure there's many schools with similar issues, I remember my old school was very similar too and the 'back corridor' had many a motor bike time trial take place over its 100m - subdivision would definitely have messed up that game!!

John.

[TickityBoo]

I would've thought that the cost of creating a protected corridor would've outweighed the cost of supplying cross-corridor smoke control doors.  Isn't there a lot of classroom glazing to replace with FR glass?

At the end of the day, if they have an L3 system, create a protected corridor and keep it completely sterile and explain their approach in their risk assessment, I think they've done enough from a life safety point of view and wouldn't push it.  Many schools don't even have detection to ensure early warning.  And with their approach, fire and smoke should be contained within one classroom long enough for persons to evacuate, rather than potentially affecting a large section of corridor up to the cross-corridor doors.

You might ask them to "consider" the installation of cross-corridor doors for the reasons already discussed, but I would leave it at that.  You've got to be reasonable under the circumstances.