new building fire doors

[seth119]

 Help needed  I  undertook  a inspection on  a new community school its is two stores high with a lift and a set of escape stairs either  end which is 110 wide at the bottom of the stairs is a protected corridor that meets the travel distance, however they is also is a escape door that leads directly out side  ( great I hear you say)  but the door is 810mm wide  I questioned the building inspector because the building hasn’t been signed off yet, he’s reply was they are SUPPLEMENTARY doors and don’t need to meet the current regulations of been 1050 wide to meet the guide of doc B on numbers of 170 - 220.

I have never heard that one before !!!!

[thebuildinginspector]

When occupants reach the bottom of the stair, has the means of escape been designed for the occupants to escape through the corridor to the final exit or is the 810mm wide door supposed to be the final exit? 

If the final exit is the door at the bottom of the stair then it shouldn't be any less than the width of the stair i.e. shouldn't reduce along it's route and it's plainly wrong.

If occupants are to go through the corridor on their route to the final exit and not use the door at the bottom of the stairs then I wouldn't be too concerned.

Nope, never heard of supplementary doors either!

[kurnal]

If occupants are to go through the corridor on their route to the final exit and not use the door at the bottom of the stairs then I wouldn't be too concerned.

Depends on the level of protection to the corridor. In protected routes you stop counting the travel distance. You should not then have to leave the protection of the staircase and escape through another corridor with rooms off- if this is the case then the final exit at the base of the staircase should be wide enough to take those people oming down stairs- and  maybe the people from the ground floor corridor as well in some cases.

[seth119]

Kuranl That is how i see it to thought I might be going mad with supplimentry fire doors!!!!!

[thebuildinginspector]

Kurnal - Agreed, goes without saying that the corridor should be part of the protected route, terminate at the final exit and the occupants shouldn't have to leave the route to get to the place of ultimate safety.  Oops - should have made that clear!

[kurnal]

I agree buildinginspector but Its a point lost on a number or architects and building controls these days. I always thought it was fundamental underpinning knowledge but have encountered this problem twice in new buildings in recent weeks.

[thebuildinginspector]

Kurnal, yes, you're right it is lost sometimes with Architects and worse it's not correctly intepreted sometimes by BCO's;  I see it frequently.

On a general point regarding travel within a protected route, there's one area I just don't get.

Imagine a simple rectangular building with a staircase at either end and a protected corridor between the two with all the rooms facing onto the corridor.  Obviously the travel distance is measured from the furthest point within one of the rooms, but this should be to the storey exit and not to the protected route (para 3.1), otherwise you could have an infinite length of corridor!

But in the situation described in the original posting, when occupants reach the storey exit and descend the stair within the protected route, at the base of the stair should the protected route extend to include the corridor there isn't any limit to the length of corridor.

[kurnal]

Yes  buildinginspector I think the problem is that this point has not been well explained in any of the guidance documents since the old A5 size red, blue, and brown guides issued under the fire precautions act.

These guides made that very clear point about what constitutes a protected route and put it in context. I don't any longer have copies of the guides but from memory it went something like this:

The distance of travel should be measured as the actual distance to be travelled  between any point in the building and the nearest storey exit. A storey exit may be a final exit or a protected stairway.

All staircases used for means of escape should be separated from the remainder of the building by a fire resisting construction and fire doors. The only doors opening into a protected staircase should be doors to WCs. or protected corridors. If doors to rooms open directly into the staircase then you should consider whether this staircase is a protected stairway.

Where you have a protected stairway it will not be necessary to have regard to the distance of travel beyond the storey exit. Where you do not have a protected stairway it will be necessary to include the stairway in the total permitted distance of travel.

Well that's what I think it said. If anybody has a copy of the guidance and can give us the exact wording I would be grateful.

The point of the guidance was that in order to discount any part of an escape route from the travel distance calculation then that element would effectively be separated from any room containing a fire risk by at least two fire doors i.e. effectively a lobby approach. We see this reflected in the current ADB where if a staircase is protected by a  lobby  there is no need to discount the staircase for the calculation of means of escape.

As I recall the old guidance always left an element of discretion or judgement on the individual as to whether it was a protected stairway or not.

[AnthonyB]

I have all the old guides as PDF's, but are scans so would have to retype word for word, if anyone has the time to do this I will forward a copy.

[kurnal]

Hi Anthony
If you have pdf copies of the first fire precautions act guides which were produced in an A5 booklet- red was hotels, brown was factories and blue offices and shops I would very much appreciate a copy. I have the later A4 size ones (red uncertificated premises, blue certificated premises, pinky lilac for hotels) .

[thebuildinginspector]

Anthony

Likewise, I'd be grateful for a scanned copy.  My email address is on my Profile page

Thanks in advance

[Tom Sutton]

I have all the old guides as PDF's, but are scans so would have to retype word for word, ......

Not if you use a OCR software I use TextBridge 11 which I think is pretty good however there are better ones but more expensive.

[AnthonyB]

Ah you mean the very very original booklets! I have a genuine copy of the first ever Hotels & Boarding Houses one, but my PDF scans are of the later A4 versions, but I'll see if my sources have the originals....