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FIRE SERVICE AND GENERAL FIRE SAFETY TOPICS => Technical Advice => Topic started by: Tradeoff on January 09, 2008, 09:15:36 PM
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Does anyone know whether a new TB is being developed to cover void protection? TB11 has been removed leaving no code compliant method of removing sprinklers from ceiling voids over 0.8m - opinions welcome on the subject
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Tradeoff, I would have to ask why do you want to remove sprinklers from voids? they are afterall there for a reason? Not aware of a new TB??
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Voids can be a problem but I am sure the new TBS issued alongside BSEN12845 do have a get out clause. Will try to look it up tomorrow. As far as I recall there is a clause allowing them to be omitted if there is no fire loading in the void - and some clause about pvc cables- as always with all parties agreement. Or you could subdivide into two voids each less than 800mm.
Maintenance is impossible and this is the main reason for wanting to omit them.
In cautionary terms recently a sprinklered supermarket in Chesterfield was gutted by fire that originated in a roof void above the sprinklers. Awaiting the investigation into the Marsden Hospital with interest.
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Under the original BS 5306 part 2 TB11 gave clauses where sprinklers could be omitted from a void. TB 11 required the void to be non-combustible and used as a non return plenum for H&V, smoke extraction etc. There are many circumstances where sprinklers were not installed in voids over 0.8m especially in retail environments (Marks & Spencer do not sprinkler voids). Therefore, with the change in code the new CEN standard has not provided a replacement for TB11. However, i hear rumours that a new TBS is in the pipeline?
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Hi Tradeoff
Sorry for the let down but on checking the BSEN today I find my memory had let me down. As you clearly are aware Clause 5.4 deals with protection of concealed spaces and indeed the comments in respect of the electrical cables are to justify protection of spaces smaller than 800mm.
If you hear more about the new TB please keep us informed.
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New TB's have just been released to supplement the BS EN 12845 sprinkler standard.
TB 230 covers void protection and allows for voids over 800mm to be unsprinklered when specific criterias are met, namely the void be non-combustible.
It is recommended that TB 230 is effective from September 2008. (No chance, with such savings available, fire engineers and end users will jump straight onto this).
TB 229 has also been introduced, this effectively replaces TB 24 - allowing for reduced water supplies for both OH & HH risks.
At last the sprinkler industry has seen sence and brought back fire engineering reality into the design element.
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Thanks for the information