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FIRE SERVICE AND GENERAL FIRE SAFETY TOPICS => Fire Safety => Topic started by: Tom Sutton on June 19, 2007, 07:52:49 PM

Title: Surface Spread of Flame.
Post by: Tom Sutton on June 19, 2007, 07:52:49 PM
“It is impossible for any self-contained or portable structure to fully comply with Class 0 fire regulations due to the nature of the classification.  Class 0 should only properly be applied to lining materials when used as an integral part of a buildings structure.  

Class 1 indicates a good performance in terms of surface spread of flame. Class 0 has the same requirement for surface spread of flame, but in addition also has a requirement to limit heat release.
 
Design and material choice for this project has been undertaken with this in mind, all materials specified are of the highest practicable fire rating and the design has specifically avoided the use of any materials that represent an undue risk.”

Would anybody disagree with the above statement if so where and why?
Title: Surface Spread of Flame.
Post by: wee brian on June 19, 2007, 10:22:18 PM
It doesnt make sense. what are you getting at?
Title: Surface Spread of Flame.
Post by: Tom Sutton on June 19, 2007, 10:54:34 PM
Quote from: wee brian
It doesnt make sense. what are you getting at?
Can a self-contained or portable structure meet a class O standard or does it only meet that standard when it is lining fixed to a wall in a building. The second paragraph, is this a reasonable description of class 1 and class O.
Title: Surface Spread of Flame.
Post by: kurnal on June 20, 2007, 07:00:24 AM
TW
In making your statements have you had regard to appendix E and Appendix A of the ADB. Theres also some information in B2 as well.

I dont really understand your statements about class O only applying to lining materials - you are  somewhat undermined when brickwork and blockwork are cited as class O in table A8, as these are often true elements of structure.  

Besides the European standards are taking over and its all getting academic.
Title: Surface Spread of Flame.
Post by: Tom Sutton on June 20, 2007, 03:55:30 PM
I apologise I should have been clearer with my posting, also I have edited the first posting.

I received a question from a manufacturer of point of sale displays, in duty free areas of airports because the airport had stated the displays should meet a Class O standard. I explained that Class O originated from the Building Regulations and referred to the spread of flame characteristics of elements of structure (Walls and Ceilings) in circulation areas. It could not be applied to portable displays as I would consider them as fittings and furnishings. I gave him some references and he did some research.

He now has got back to me and wishes to include, the above passage, on any quotation / documentation where a client requests ‘Class 0’ compliance in the hope of allowing common sense to prevail if the above statement is correct.

There is obvious confusion, both Wee Brian and Kurnal proves that, so I would suggest he should revises the wording to make it clearer and not just give facts for the reader to work out the meaning. I take Kurnal’s point about the linings but the facts are not totally incorrect and with some modification I feel it would be acceptable.
Title: Surface Spread of Flame.
Post by: Mr. P on June 21, 2007, 08:10:29 AM
It's not just the display units, but the materials on/in them.  Is he controlling those too?
Title: Surface Spread of Flame.
Post by: kurnal on June 21, 2007, 03:37:26 PM
Thanks TW I see where you are coming from now.
Its a real problem, trying to do business in this arena of standard clauses and prescriptive conditions imposed by landlords without any understanding of why  they are imposed.

Clearly within the duty free retail area any fire loading imposed by a plastic/ paper/cardboard sales display is going to be insignificant when compared to the thousand or so litres of flammable liquids on the shelves along with the aerosols and all their associated packaging.

In an escape route or mall it may be a different matter. But trying to make them see that is going to be a problem.
And any explanation such as the one you propose is only going to be of use if the facilities manager understands it. Which if he does he probably wouldn't be imposing such a general condition in the first place.

Your contact has two options really. Manufacture the display to meet the most stringent of conditions (The Scottish guides  are an ideal source of standards which they present as benchmarks) so it can meet or surpass anybodies standards, or to use a specific risk assessment in each location. If the display is not increasing the overall fire load within an area, and its in a retail unit then whats the problem?
Title: Surface Spread of Flame.
Post by: John Webb on June 21, 2007, 03:51:01 PM
BAA had work done on the fire behaviour of duty-free goods shops 10 years ago and the efficacy of standard sprinkler systems to cope with a fire in such shops. I do not know to what degree they've made the results public, however.
This work may be relevant in any risk assessment of these point of sale displays - it is unlikely that they will make a significant contribution to fire load or fire spread if sprinklers are present.
Title: Surface Spread of Flame.
Post by: Tom Sutton on June 21, 2007, 07:48:56 PM
Quote from: kurnal
And any explanation such as the one you propose is only going to be of use if the facilities manager understands it. Which if he does he probably wouldn't be imposing such a general condition in the first place.
I agree but he is just trying to pre-empt future similar demands and knows the chances are slim. The good thing is with his research he now has a reasonable understanding of the situation and can deal with future demands more easily.
Title: Surface Spread of Flame.
Post by: Fishy on June 21, 2007, 09:25:44 PM
Yes - I would disagree, I'm afraid.  It's perfectly possible to test a material of the sort used in point-of-sale displays (note: not "structure" - BSA 476 parts 6 and 7 do not relate to structures - only materials) and get a Class '0' rating.  I used to work in a Lab. where tests on these sorts of materials were a matter of routine.

BAA are not bound to limit their requirements to those in the ADB.  They are perfectly at liberty to use the performance classifications therein to support their own, additional requirements if they wish.  If your client chose not to comply, he would probably be in breach of contract.

BAA are one of the most knowledgeable 'buyers' of fire safety that I know of - they employ their own Fire Safety Engineers and Managers who have developed their specifications.  I'd be reasonably confident that they knew exactly what they were asking for, and that it was achievable, when they put this spec. together.

Quote from: twsutton
“It is impossible for any self-contained or portable structure to fully comply with Class 0 fire regulations due to the nature of the classification.  Class 0 should only properly be applied to lining materials when used as an integral part of a buildings structure.  

Class 1 indicates a good performance in terms of surface spread of flame. Class 0 has the same requirement for surface spread of flame, but in addition also has a requirement to limit heat release.
 
Design and material choice for this project has been undertaken with this in mind, all materials specified are of the highest practicable fire rating and the design has specifically avoided the use of any materials that represent an undue risk.”

Would anybody disagree with the above statement if so where and why?
Title: Surface Spread of Flame.
Post by: kurnal on June 21, 2007, 10:29:05 PM
Yes I agree Fishy that any landlord can set whatever rules they like. But prescription is something I loathe in any scenario or walk of life. Its what jobs worths thrive on. And generally these rules are set just for others to comply with. In the same way as Crown Property is exempt  from so many of the rules that shackle the rest of us.
I dont think that the BAA have much interest in the nitty gritty of fire safety at  regional airports  do they? I dont know - but I dont see much evidence of it if they do.
Title: Surface Spread of Flame.
Post by: wee brian on June 21, 2007, 10:31:39 PM
Point to note - you can get class o two ways, Surface spread (class one) + fire prop. or any non-combustible material.

So Class O neednt be a lining material, althoughthats really what it was meant to be for. You can get some quite nasty stuff clasified as class O if you know what you are doing.
Title: Surface Spread of Flame.
Post by: Tom Sutton on June 21, 2007, 11:57:57 PM
Your first point wee brian was raised earlier in the discussion by Kurnal your second I agree with if I remember correctly polystyrene ceiling tiles disappear so fast that under test they meet the Class O criteria.

Fishy As I understand Class O is defined only in Building Regs and does nor appear in any BSS - check out ADB vol 2 Page 120 Para 13 - so I would reason that outside the building regs it does not exist. Furniture and Fittings are not controlled by Building Regs check out ADB vol 2 page 63 B2 iv unless you consider portable point-of-sale displays are not furniture and fittings?
Title: Surface Spread of Flame.
Post by: John Webb on June 22, 2007, 11:08:55 AM
I've never been closely involved with surface spread of flame tests, but I'm fairly certain Class 0 is defined in the BS476 series if only to cover something that is better than the behaviour of a class 1 material.
Fire Research carried out full-scale tests some thirty+ years ago to compare corridors lined with different materials as graded by the BS476 test. There was general agreement between the way fire spread in the full-size fires to their rating by BS476.
By the way, never use 3mm ordinary hardboard in a corridor - it's fatal for fire spread - we had 40ft flames coming out of the end of the corridor!
Title: Surface Spread of Flame.
Post by: Tom Sutton on June 23, 2007, 08:20:46 AM
Quote from: John_s.webb
I've never been closely involved with surface spread of flame tests, but I'm fairly certain Class 0 is defined in the BS476 series if only to cover something that is better than the behaviour of a class 1 material.
John I think ADB vol 2 Page 120 Para 13 would disagree with you.

However I think the important point is when ever deciding the desirable fire characteristics of a item, a risk assessment should be carried out as suggested by Kurnal, to determine is a standard necessary and if it is, the most appropriate standard for it.

When dealing with elements of structure spread of flame is important because walls and ceiling stretch from one end of the building to the other and you do not want a fire spreading at a high rate of knots, for a portable display stretching a few metres is it so important. Maybe some degree of fire retardancy is more appropriate, flame, cigarette or ignitability test would be better?

What I am suggesting before anybody specifies a standards is it the most appropriate standard for the situation.
Title: Surface Spread of Flame.
Post by: John Webb on June 23, 2007, 10:13:00 AM
I've not got my Vol 2 copy yet, neither do I have access to any of BS476, so I am happy to be corrected.

I'd agree with you that the FRA route seems most sensible (and is the 'legal' way to go), but that of course does not prevent someone from demanding their own (higher?) standard on their own property.
Title: Surface Spread of Flame.
Post by: Martin Burford on June 23, 2007, 11:20:54 AM
twsutton
Class O is a requirement for ESCAPE ROUTES............and is non combustible
Class 1 is a requirement for rooms, other than small rooms.
Portable structures should conform to Class 1, in my opinion. however what type of portable structure were you suggesting...Marquees and the like ?
Conqueror
Title: Surface Spread of Flame.
Post by: Tom Sutton on June 23, 2007, 11:31:32 PM
John being a cheap skate I use the downloaded version from http://www.planningportal.gov.uk/england/professionals/en/1115314110382.html

Conqueror, it depends on which guidance you are reading. If you are reading the building regs Class O is a requirement for circulations spaces. (Which could be ESCAPE ROUTES)? The definition of class O is a little broader, ADB vol 2 Page 120 Para 13, see below,

13. The highest National product performance classification for lining materials is Class 0. This is achieved if a material or the surface of a composite product is either:

a. composed throughout of materials of limited combustibility; or

b. a Class I material which has a fire propagation index (big I) of not more than 12 and sub-index (little i) of not more than 6.

Note: Class 0 is not a classification identified in any British Standard test.

The type of portable structure in question was a point of sale display, in duty free area of an airport.
Title: Surface Spread of Flame.
Post by: John Webb on June 24, 2007, 01:06:48 PM
Thanks - all noted.
Title: Surface Spread of Flame.
Post by: Fishy on July 05, 2007, 11:24:19 AM
With regard to the second para. - your first statement is correct, but your conclusion does not follow.  BAA are actually exempt from the Building Regulations, but there is absolutely nothing stopping them demanding contractually that their suppliers conform with as much or as little of the relevant guidance documents as they wish.  They can demand compliance with French, German, Zimbabwean or Outer Mongolian guidance and/or regulation if they want to, and whilst you or I might have views on how sensible it is, if that's what they want then any suppliers, tenants etc just have to like it or lump it!  If their suppliers don't comply, they'll be in breach of contract.

As another example, London Underground are exempt from the requirements of the Building Act, but use Class '0' in some of their materials fire performance requirements, for installations that are clearly not within the scope of 'linings' as defined in the ADB.  They also demand extraordinary high levels of smoke and toxicity performance too.  If your client were to be setting up shop in one of their stations, any bleating about the ADB being inappropriate / inapplicable would receive a very short, succinct and definitive answer!

I'm afraid that your client just has to do the necessary and comply.  I haven't tried, but I imagine a quick trawl of the Internet would reveal suppliers of Class '0' fabrics or fabric-type materials.

Quote from: twsutton
Your first point wee brian was raised earlier in the discussion by Kurnal your second I agree with if I remember correctly polystyrene ceiling tiles disappear so fast that under test they meet the Class O criteria.

Fishy As I understand Class O is defined only in Building Regs and does nor appear in any BSS - check out ADB vol 2 Page 120 Para 13 - so I would reason that outside the building regs it does not exist. Furniture and Fittings are not controlled by Building Regs check out ADB vol 2 page 63 B2 iv unless you consider portable point-of-sale displays are not furniture and fittings?
Title: Surface Spread of Flame.
Post by: Fishy on July 05, 2007, 11:27:32 AM
Conqueror:

I'm afraid that your first statement is incorrect - the requirements for a material to be demonstrated as non-combustible are far more demanding than those for Class '0'.  You can easily treat timber to make it Class 0, for example.  It is impossible to make it non-combustible (as defined in the Standards).

Quote from: Conqueror
twsutton
Class O is a requirement for ESCAPE ROUTES............and is non combustible
Class 1 is a requirement for rooms, other than small rooms.
Portable structures should conform to Class 1, in my opinion. however what type of portable structure were you suggesting...Marquees and the like ?
Conqueror
Title: Surface Spread of Flame.
Post by: Tom Sutton on July 05, 2007, 07:42:39 PM
Quote from: Fishy
whilst you or I might have views on how sensible it is
I agree with you fishy on what you have said but the above sentence in your submission is my main point. If the BR do not apply, why quote standards that only exist in that legislation.
Liverpool airport owned by Peel Holdings does BAA control them?
Title: Surface Spread of Flame.
Post by: kurnal on July 05, 2007, 09:54:27 PM
TW
The building Act 1984 originally exempted the BAA abd CAA from compliance with the Building Regs. This was then amended by the Transport Act 2000 to cover all licenced operators of airports.

See section 7 of the this link
http://www.opsi.gov.uk/si/si2001/20014050.htm

Fishy you are bang on but it does p*** me off cos its always a matter of do as I say not as I do. Thats something I hate but as you say its a fact of life.