ESFR Sprinklers and hanging garments

[kurnal]

I have been searching without success for information on ESFR sprinklers and fairly large scale hanging garment storage. Have come across an existing warehouse with roof level ESFR sprinklers K360 heads - so a very meaty system, but since the system was installed use of part of the building has changed. The system was originally was designed for Classification 4 goods in ST5 mode storage.

Have been looking on the FM website for data but there is no reference whatsoever to hanging garments in respect of suppression mode sprinklers. The configuration is back to back racks each with with three rows of garments one above the other on fixed rails to a height of about 5m with a roof height of about 6.5m so its not too scary but the blocks of storage are currently very big without fire breaks and very much exceeding the AMNOSO area.

Its one of those jobs where there is clearly a problem but in the absense of data, finding the right solution in terms of limiting height and area of  blocks of storage is not easy. I will of course be consulting the insurers but was hoping to be able to offer some potential solutions.

I would be very grateful if anyone can point me in the direction of a source of data that I have not considered.

[Phoenix]

Sorry if I'm being too basic, but you have looked through TB209, have you?  It doesn't seem to like, for example, hanging acrylic fabrics.

Stu

[kurnal]

Thanks Stu. Yes I took that at its face value- acrylic fibre yarn and other materials that are not easily extinguished by sprinklers.

If you compare it with a shop, in which single and double rails of clothing can be tightly packed in to a shop floor and may be covered by OH sprinklers delivering just 5mm/sqm/min  then three rows is not all that much worse. And boy these are big - K360 heads as opposed to the K80 in a typical shop. Probably 25mm/sqm/min? So it seems a bit extreme  to say no you cant put three rows in.

I see the big problem being the potential rapid lateral spread of the fire to affect more sprinklers than the water infrastructure can support, unless we do something to limit the potential area affected by fire.

Under ESFR sprinklers I could stack for example exposed foam rubber to a height of 7.6m with K200 heads, thats easy because this appears in the table.

Both the FM and TB209 are very clear that  ESFR must only be used to cover risks for which tests have been carried out. It seems no tests have been carried out on hanging garments and ESFR. So we cant do it.

But I cant tell a fashion chain to stop selling clothes and it would be crackers tell them to take out the sprinklers or downgrade them just because because hanging garments dont appear on the tables!

[Phoenix]

I think you've found a bit of a gap here.  I looked at clause G3 in 12845 to see what that said but it specifically excludes your configuration.  It's likely that someone will know the way forward for you but if you can't get an answer anywhere else email me and I'll get an answer for you.

Cheers,

Stu

[wee brian]

I suppose the first question is why are the sprinklers there.  I suspect you've already been through all that but are they necessary to satisfy the FSO or is it an insurance requirement?

Anyway, try ringing John Stepens at the FPA, or Corinne Williams at BRE.

[kurnal]

Sprinklers are there for both life safety and propery protection. Building has been up a number of years. Am going to discuss with Factory Mutual.

[John Webb]

Kurnal - may seem a silly question but I'll explain why I ask it. What sort of coat-hanger are the garments on?

Just that if they are plastic hangers (or plastic hangers with metal hooks) it's very likely that the hangers will melt fairly early on in any fire and the clothing will drop down - this may cause fire spread to clothing below or you'll end up with heaps of clothing on the floor, possibly burning, possibly not. In either case this may have some impact on the capability of the sprinkler system to control/extinguish the fire.

I hope they've got good drainage by the way!

[Mike Buckley]

"Am going to discuss with Factory Mutual."

Good luck, my experience of FM is that they use their own specification which is higher than LPCB with their own licenced kit. A place I worked at had a sprinkler system which was up to LPCB but their suggestion would have meant we needed to rip it out and replace it.

[kurnal]

Thanks to all.

The bottom line I guess is that ESFR was designed for specific scenarios and hanging garments was not one of them. We have put a proposal to the insurers and are awaiting their response. Meanwhile have also asked the original sprinkler contractor to review the proposal.