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FIRE SERVICE AND GENERAL FIRE SAFETY TOPICS => Fire Safety => Topic started by: Sherpa on May 15, 2008, 07:30:20 AM
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Is any one seeing a move away from the prescribed requirements of L1,L2,L3 & L4.
When considering detector locations, more and more of my customers seem to put what they want, where they want, and then call it L5 life safety detector layout.
My understanding is that an L5 detection layout would have to be a very carefully considered design, carried out by a fire engineer.
Any thoughts please.....
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I think the concept of L5 was to cover specific locations where automatic detection would not normally be required to be installed but in the circumstances it had been decided that automatic detection could be used as a trade off instead of meeting some other structural requirement or allowing an extended travel distance.
But like you sherpa I am finding the system abused, especially where the installation engineer is not satisfied that the design meets the the letter of BS5839 - rather than discussing the variation with the designer or simply issuing the commissioning certificate with the variation declared the engineer has classified what is actually say an L2 with variations as an L5. In my view this is down to either laziness or ignorance by the installation and/ or commissioning engineer thinking they are covering their backs.
And its not getting picked up by the architects, clerks of works or building inspectors.
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I think the concept of L5 was to cover specific locations where automatic detection would not normally be required to be installed but in the circumstances it had been decided that automatic detection could be used as a trade off instead of meeting some other structural requirement or allowing an extended travel distance.
But like you sherpa I am finding the system abused, especially where the installation engineer is not satisfied that the design meets the the letter of BS5839 - rather than discussing the variation with the designer or simply issuing the commissioning certificate with the variation declared the engineer has classified what is actually say an L2 with variations as an L5. In my view this is down to either laziness or ignorance by the installation and/ or commissioning engineer thinking they are covering their backs.
And its not getting picked up by the architects, clerks of works or building inspectors.
Totally agree. Also think that the vast majority of the above named professions wouldn't know an L1 from an L4. I don't think they care as long as they have a piece of paper in their hand so they can lay the "blame" somewhere else.
And the piece of paper could be a toilet roll, because they also don't know what certification to expect.
Since 2002 we have never ever ever been asked to supply Design or Installation certificates to anybody.
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Kurnal and David are Spot on with their comments. L5 systems are designed to satisfy a specific fire safety objective based on a fire fire engineering solution. It is my understanding that such a solution would also need to be described in writing and form part of the category description for an L5 category for it to be acceptable.
If you ever see a request for an 'L5' system then always ask for a written description of the risk identified and the solution engineered to overcome it.
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Yes I too have to agree with your comments.
Category L5 must not be used as an excuse to justify a cost cutting excercise or substandard fire precautions.
My brigade / authority is now looking into the prospect of realing in more installers and RP's to account for naughty little things like this.
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Yes I too have to agree with your comments.
Category L5 must not be used as an excuse to justify a cost cutting excercise or substandard fire precautions.
My brigade / authority is now looking into the prospect of realing in more installers and RP's to account for naughty little things like this.
Damn right..!!
There is nobody who seems to police the certification of fire systems anymore. The end user generally doesn't have a clue what to expect and the average installer still seems to get away with scribbling a name on the back of a fag packet.
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Category M with L5 enhancements - that's what I saw in a very big national fire alarm company's commissioning certificate for a new system. It was basically meant to be an L2 but they made a pig's ear of the 'areas opening onto MoE' bit which explains the change in cert. Wasn't picked up until a couple of years later as the cert had just been filed, not read.
L5 to me normally (but I admit not always) means a category M with the odd head here and there for things like access rooms, not a substandard 'almost' L3/L2/L1
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Glad to see its not just me!....It seems the L5 category is been abused, maybe it should not be called L5 and should be changed to S5 (special 5).
Because its called L5, customers believe they have a system designed around life safety, however an L5 design can fall well short of this. Its what ever the designer wants to put in and there are no wrongs or rights.
I also agree with David Rooney that the whole certification side of things has deffo gone down hill. I find it increasingly difficult to get someone to take on design responsibility and issue the appropriate certificate. Equally the installers normally also look quite blank when you ask them to issue a BS5839 install certificate.
I would be very interested to read any published articles on the true intent of the L5 category, is anyone aware of such articles?.
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Not seen any articles or guidance on this other than for the manufacturers design guides (some of which are not helpful - eg the ADT design guide gives an example of the use of L5 in compensation for a lack of structural fire resistance but they do not give any further detail or explanation on how and with whom such trade offs may be agreed.)
Most of the others eg Gent just give a one line explanation of the category. In the absence of proper certificated design as seems widespread from this thread its not surprising that the category is being abused.
I attended an ADT seminar a few years ago delivered by Colin Todd and still have a copy of his hand out which, still only a paragraph, explains the intent very well and would be happy to fax you the relevant page if it would help. But it wont tell you any more than you already know.
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In your opinion, who would be QUALIFIED to carry out a L5 category design layout?
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I agree with comments posted so far in that generally L5 systems are abused. I also think that many fire alarm designers are afraid of commissioning L5 systems as they are unsure of how to meet certain specific fire safety objectives. They prefer to go for L1 to L4 as the location of detection is more prescriptive, easier to design and then commission.
I would suggest that a competent or (qualified if you like) person to design an L5 would be a competent fire risk assessor with some fire alarm knowledge and design training such as the BAFE course in fire alarm design.
In my experience an L5 system is quite straight forward. You can have a pure manual system say for an office with one smoke detector to cover an inner room or detection to compensate for lack of fire resistance in a dead end. It may also be used to compensate where the travel distance exceeds the recommended norm or a deviation from a building regulations requirement.
BS 5839 states that the design of any system should be based on the outcome of the FRA. In conjunction with the fire alarm installer the commissioning certificate should clearly state the rational and objective of any L5 system. What tends to happen is the alarm system is designed and installed first and the the FRA is an after thought……in my view
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In your opinion, who would be QUALIFIED to carry out a L5 category design layout?
Thats a difficult question and there are two aspects to it.
1- someone who is qualified to recognise the life safety implications of the building- how it is to be used, who is to use it and who may be at risk, any variations from benchmark design standards and their effect on the life safety of all who may find themselves affected should a fire occur in this building (including firefighters for Building Regulations approval).
This person must determine the equivalence of any fire safety solution they install such as a category L5 alarm system to a code compliant design.
This person could be an architect, a fiire consultant or a building control officer / approved inspector and sometimes all three will be involved in determining the category in the first place. All these people should have a detailed knowledge of design codes and benchmark standards and a level of fire engineering to some extent but probably wont know their firetuff from their end of line resistor when it comes to system design.
2- The actual alarm system layout must then be designed by a competent fire alarm design engineer - probably the M&E contractor- taking into account the detail of the installation, the actual provision, number and siting of alarm system components to meet the requirement identified by the building design team and the BS.
I know thats ideal and is cobblers compared to real life. Most likely an architect will put a few detectors on the plan and a sounder here and there for good measure and give to to the local sparks - or indeed just tell the sparks to install an L1/2/3/4/5 without any further guidance or design. And very often the choice of system category is more closely related to the budget available than a life safety need.
I am often asked to carry out fire risk assessments in newly erected buildings and am sometimes at a loss to understand the fire strategy. Very often the design has been agreed between the architect and approved inspector and sometimes these are employed by different divisions of the same firm.
I have heard clients say to approved inspectors - if you dont approve this you wont get the next job.
I have seen designers and approved inspectors picking bits out of DD9999 that they like and ignoring the caveats and the bits they dont like. I do have some concerns for the industry.
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The whole L5 thing is a nonsense. When a customer comes to me and informs me that they have been asked for an L5 but cannot get official guidance they then ask me.
I am unwilling to do it ,so they then do a design on their own "risk assessment".
Like Dave mentions-who's responsible now for producing a design certificate?
As with more installs now that customers do not want the responsibility for the design so go for all over coverage,where a professional risk assessment could reduce it.
They can't win. Pay for a pro risk assessment and then get a reduced coverage or get blanket cover without the cost of a pro risk assessment cost.
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Surely the cost of a pro FRA as you put would not compare to the difference in cost beween an L1 and L5 system?
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customers don't see it that way. They do not wan't to pay for a fire alarm system in the first place without the cost of a RA too.
Things were much better when the Fire Officer did them and told the customer what coverage he needed insted of now where no one wants to take the responsibility.
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customers don't see it that way. They do not wan't to pay for a fire alarm system in the first place without the cost of a RA too.
Things were much better when the Fire Officer did them and told the customer what coverage he needed insted of now where no one wants to take the responsibility.
Exactly that.
Our BAFE inspectors have said that we should not mention the words "Risk Assessment" in our quotes other than to tell the customer it's their resposibility as we are not qualified to carry out such assessments.
But the customer generally says "I need a fire alarm system" and look to us to tell them what they need.
As you say Graeme, far better when the customer got told by the fire authority (who they generally trusted and listened to) as to what they needed. Now the customers don't want to pay for an assessment, but expect the fire installer to decide the appropriate level of coverage.
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But Dave lets not overlook one small detail.
The client (Responsible Person) has an absolute duty in Law to carry out a fire risk assessment and to record the prescribed information if more than five persons are employed or a licence is in force.
The risk assessment cannot be considered suitable and sufficient if it does not identify and consider the appropriate means for detection and warning of fire.
If the client cannot do this for themselves they are not competent to carry out the risk assessment and have an absolute legal duty to seek competent advice.
So theres nothing wrong wth the system, its just that the client is unwilling to do what they are legally obliged to do and wants to slope shoulders.
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But Dave lets not overlook one small detail.
The client (Responsible Person) has an absolute duty in Law to carry out a fire risk assessment and to record the prescribed information if more than five persons are employed or a licence is in force.
The risk assessment cannot be considered suitable and sufficient if it does not identify and consider the appropriate means for detection and warning of fire.
If the client cannot do this for themselves they are not competent to carry out the risk assessment and have an absolute legal duty to seek competent advice.
So theres nothing wrong wth the system, its just that the client is unwilling to do what they are legally obliged to do and wants to slope shoulders.
That's all true, but my point is that the vast majority of customers (small to medium business owners generally, including a lot of private hotels) either don't understand the RRFSO and its implications, don't want to pay someone else to do an RA, don't want to do it themselves, and don't know what information is required anyway, despite the guides they also haven't heard of !
Yes they have a legal duty but they don't believe it (generally) when they are told by a lowly fire alarm installer rather than an independent authority figure like the Brigade.
I've still never had an enquiry through from a "small to medium" end user that has stated they have a RA available and that they have concluded the level of detection required for their building....
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No all L5 systems would need to be designed by those with extensive 'fire engineering' experience.
For example a premises that otherwise needed only manual call points but also a had a fire door electromagnetically held open and automatically closed upon detection of smoke by detectors installed either side of it would be designated L5/M
However, I understand the point being made is that those who don't understand the requirements of categories are trying to hide behind the L5 designation. But since the L5 category is designed to satisfy a specific fire safety objective other than that of a category L1, L2, L3 or L4 system then I don't see how they are getting away with it.
I have noticed recently that almost every premises insurance policy I have seen includes a requirement for at least a L2 system. Whilst I don't agree with the insurance companies just 'guessing' a category as they appear to be doing, the simple fact is that anyone not doing what their insurance policy requires, despite the findings of any FRA, is likely to be uninsured.
I think the first step these days for anyone being asked to design a fire alarm is to ask what the insurance company has asked for. In fact, in the future, I see a role of a professional FRA is possibly going to be as an 'argument' to reduce the insurance companies requirements when the FRA reveals the category demanded by the insurance company is OTT!
With respect to the 'good old days' of fire officers deciding what was to be installed am I the only one who came across numerous poorly designed systems? However, I would agree that maybe the Fire Service should take on this responsibility once again but they should then be able to charge a commercial rate for doing so and have departments of properly trained personnel to do the work to an agreed national standard.
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You cant please everybody. Half of industry wants to manage the risk they create and not to have public servants on behalf of the nanny state poking their noses in and telling them what to do.
The other half are too busy trying to make a living and havn't got time to make fire safety or any other health and safety matter a priority until it bites them on the bum.
The new fire safety order was written with the first group in mind. The second group need a robust enforcement regime to make sure that they give fire safety the consideration it deserves - always on a risk appropriate basis of course. Lancashire fire service seem to be at the forefront in recognising this and taking people on. Are they right? Depends what society wants.
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For me one the main problems is the designation L 5 (life), this suggests to the customers they have a system designed with life safety as the key design parameters.
However the reality is a L5 category system can be well short of a life safety criteria, with other design constraints such as the cost or just fire engineering ignorance been the overriding factors.
Unfortunatley with the RRO putting responsibility back in the hands of the customers, they will cut corners. With no overriding enforcing authority they will try and put in the least amount of fire detection possible.
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For me one the main problems is the designation L 5 (life), this suggests to the customers they have a system designed with life safety as the key design parameters.
However the reality is a L5 category system can be well short of a life safety criteria, with other design constraints such as the cost or just fire engineering ignorance been the overriding factors.
Unfortunatley with the RRO putting responsibility back in the hands of the customers, they will cut corners. With no overriding enforcing authority they will try and put in the least amount of fire detection possible.
Surely general fire precautions are just that - the minimum standards. When i'm auditting, as long as the AFD provides a minimum level of protection, that's all i'm concerned about. I've got a sleeping risk coming on line that will consist of a 1 hours FR room, with a door direct to a place of safety and surrounded by AFD i.e. a designed L5 system. No problem.
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Surely general fire precautions are just that - the minimum standards. When i'm auditting, as long as the AFD provides a minimum level of protection, that's all i'm concerned about. I've got a sleeping risk coming on line that will consist of a 1 hours FR room, with a door direct to a place of safety and surrounded by AFD i.e. a designed L5 system. No problem.
GFP are not "minimum standards" they are what is appropriate for the risk. if the premises is providing sleeping then the "minimum standard" is L2
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Surely general fire precautions are just that - the minimum standards. When i'm auditting, as long as the AFD provides a minimum level of protection, that's all i'm concerned about. I've got a sleeping risk coming on line that will consist of a 1 hours FR room, with a door direct to a place of safety and surrounded by AFD i.e. a designed L5 system. No problem.
GFP are not "minimum standards" they are what is appropriate for the risk. if the premises is providing sleeping then the "minimum standard" is L2
I agree that the normative standard for sleeping is L2 - BUT - in your words Izan, it's what is appropriate for the risk, you can't have it both ways. Surely by 'demanding' an L2 (or better) in every sleeping premises, that's not risk assessment, and we're heading back to the good old days of code hugging?
What about the small sleeping premises in the guide where the recommendation is not for L2 but one of the LD standards - risk assessment!
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L5 is not well short of life safety criteria.
In prisons the system has to be designed in such a way that the detection meets the required needs but the actual placement of detectors etc cannot meet the design criteria in the Standard. Some engineering principles are used, system components are mixed and matched and the effect is to create an amalgam of components which provide coverage equal to L1 standards. however the variances in what is placed where denies the simple L1 category application. Following the Standard L5 / M is the correct standard for prisons.
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Surely general fire precautions are just that - the minimum standards. When i'm auditting, as long as the AFD provides a minimum level of protection, that's all i'm concerned about. I've got a sleeping risk coming on line that will consist of a 1 hours FR room, with a door direct to a place of safety and surrounded by AFD i.e. a designed L5 system. No problem.
GFP are not "minimum standards" they are what is appropriate for the risk. if the premises is providing sleeping then the "minimum standard" is L2
I agree that the normative standard for sleeping is L2 - BUT - in your words Izan, it's what is appropriate for the risk, you can't have it both ways. Surely by 'demanding' an L2 (or better) in every sleeping premises, that's not risk assessment, and we're heading back to the good old days of code hugging?
What about the small sleeping premises in the guide where the recommendation is not for L2 but one of the LD standards - risk assessment!
Agree with DM. Code is minimum standard. Anything above that is overprovision.
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L5 is not well short of life safety criteria.
In prisons the system has to be designed in such a way that the detection meets the required needs but the actual placement of detectors etc cannot meet the design criteria in the Standard. Some engineering principles are used, system components are mixed and matched and the effect is to create an amalgam of components which provide coverage equal to L1 standards. however the variances in what is placed where denies the simple L1 category application. Following the Standard L5 / M is the correct standard for prisons.
Hi afterburner
I am interested in fire safety in prisons and am starting a file on it.
In England I believe the latest guidance was published in 1991- please correct me If I have missed something more recent.
I understand ( from rumour and speculation only) that a current review of standards in the custody suites of police establishments is moving towards proper fire doors with seals and the use of the cell exhaust ventilation system ramped up in a fire situation with no inlet air , presumably to create a negative pressure in the cell of origin to protect the corridor outside. In the past they have allowed for some inlet air if only through leakage paths round the old pattern security doors.
They appear to be moving towards air sampling systems. I wondered if this is the sort of solution you were alluding to?
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Kurnal, replied direct to your e-mail
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Thanks Afterburner. Will be in touch.