Timber Fire Escapes

[Chris Houston]

http://news.bbc.co.uk/1/hi/england/cornwall/6953427.stm

I note the comments about the timber fire escape.  I've not seen a timber fire escape.  What are people's views on these?

[Midland Retty]

Depends really ... Risk Assessment time!

Members of the general public always regard wood as being readily combustible.

Infact during a radio phone in on the Radio2 Jeremy Vine show some callers were amazed to hear that a wooden staircase was installed at the recent hotel fire in Newquay. I agree that its not commonplace but is it necessarily wrong? The Fire Inspector obviously didn't think so.

Yet as the Cheif Fire Officer pointed out - the wooden escape staircase was successfully used during the evacuation.

At the end of the day it would require a substantial heat source to ignite it potentially and so long as there wasn't anything that could impinge onto it (within the time it took to escape) and there were alternative escape routes available I cant say id be too worried about wooden escape stairs.

As with metal staircases everything within 1.8 meters around it should be suitably FR
I accept radiant heat might play a part but in a building with early warning the staircase shouldn't become untennable until well after people have escaped.

Biggest problem I can forsee is the maintenance of it (ie poorly maintained and going rotten)

[kurnal]

Timber external escapes were common in the early 1970s when the fire precautions act suddenly led to improved fire safety standards in many older type buildings. The big problem is structural integrity as they rot, coupled with a buildup of verdigris that can make them slippery unless treated with a non slip cover that makes them rot faster.

The history means that 35 years on many of them have now rotted away and been replaced with steel.
But if they are in good condition and up to the job there is no reason to replace them as a matter of course in my opinion. Just keep a close eye in the condition.

[Tom Sutton]

Kurnal has hit the nail on the head. I remember a colleague placing a prohibition order on the first floor of a factory not because it was a timber external escape but because it was in a state of collapse due to rot. Also in the rain they were a nightmare because they were so slippery.

[firestop]

Isnt it surprising that its only just under 2 years ago that the Fire Precautions Act certificate went by the board and now we have lots of big fires.

I cant understand how a wooden fire escape stair could be so involved in fire unless the base had become a storage area for wheelybins and rubbish. A large fire source at the base would certainly create enough heat to fire the timber structure.
I hope that the doors onto the stairs were fire resisting and that all all associated glazing was of the same fire resisting standard.

The Fire Brigades now dont have the same inspection regime they used to have.

[Chris Houston]

Presumably storage under metal stairs resulting in a fire would be equally dangerous?

[jokar]

Firestop, risk assessment has been with us for a long time and in the fire safety arena since 1997.  Subject to popular opinion there have not been additional fireor larger fires or more fire deaths in commercial premises in this time frame.  The comments in the posts with regrad to rigourous inspection for timner escapes is correct.  Do not forget this was a Hotel subject to having a Fire Certificate which allowed the timber fire escape and it was used sucessfully during the fire.  The reason it and the hotel burnt was the intensity of the fire and the investiogation will eventually give us the reason for this.  Metal stairs in the same position may well distort under heat and become unusable due to extreme temperature.

[AnthonyB]

Although risk assessment existed since 97 (although it only moved to cover certified premises in 99) my experience was that most (not all) enforcing bodies stuck to certificate enforcement (& it's 'frozen in time' drawbacks) until the RRO usually simply appending a letter or leaflet reminding occupiers of their duty to meet the FP(W)Regs & most (but not all) prosecutions during this time were still under the FP Act,hence why theres been little change in stats since '97 .It's only from October 06 onwards should we be looking at cases & statistics to determine the RRO's effectiveness

[wee brian]

Conjecture - but here we go.

The Original Hotel had dreadful means of escape - When the FPA came in they installed the two external stairs. These probably reduced the number of casualties from 50 odd to 3.

The million dolloar question is - was there any FR glass in the windows that faced the stairs. If there was it didnt work very well but I doubt there was any at all.

Did this get picked up in the risk assessment?.

[nearlythere]

Do not forget that Fire Certificate standards do not prevent any building, including its protected stairways, from burning down. The Certification standard tries to ensure that all persons can escaped before this happens.

The report on the incident will be very interesting for all involved in fire safety.

[wee brian]

Absolutely - The pictures on the TV are of a fire in the stage which is of little interest to us fire safety bods. What worries me is the references to the stairs burning as people escape - that aint meant to happen. My money is on plain glass in the windows by the stairs.

[AnthonyB]

It's not unusual to find retrofitted external stairs without glazing upgrades, whilst many clients are happy to repair, weld & repaint the stairs if in poor order (which isn't that cheap) they always decide to overlook glazing issues - if non FR glazing is found to have contributed in this case then they may well think again once presented with the evidence

[wee brian]

I hope somebody checked before the walls were knocked down

[saddlers]

Whilst on this subject, I have often wondered about the fact that glazing adjacent to an external stair is not required to be "insulated" fire resistant glazing. I know the heat should dissipate due to the external location, but you have to wonder whether radiated heat could affect a timber stair, and more importantly affect the people descending the stair!!

Especially when you consider you could still have timber external escape stairs in certain scenarios as detailed in Approved Document B, although I have to admit you don't see them very often.

[kurnal]

When I encounter unprotected glazing alongside external fire escapes I do not recommend it be upgraded in all circumstances.

In sleeping accommodation, according to national guidance,  all means of escape staircases should be protected routes so I always recommend those serving sleeping accommodation be upgraded.

But for commercial and industrial premises the requirement is to ensure a fire cannot simultaneously take out multiple escape routes, and indeed in a building with two internal staircases often only one needs to be a protected route. So the same would hold good if one of the stairs was external- as long as the staircases have sufficient separation from each other  and a fire cannot take out both routes plain glazing may be fine.

Comments welcome.