The distance of sprinkler heads from pallets

[Tom Sutton]

 

In warehouses what distance should stock be stored from sprinkler head?

A question I was asked but don't have an answer other than point to the relevant standard even though its not about installation, but where to stack the pallets.

[kurnal]

Assuming we are talking about heads under a roof or a mezzanine then 1000mm is the required clear space. With in rack sprinklers its a bit different and we would need more information to help you further.

However an equally important factor is the classification of the goods stored, the mode of storage and height of the stored goods. The higher the risk the greater the required density of discharge needed. Very often it is necessary to control the height of the storage and the maximum area of each block of storage to ensure the fire loading remains within the capability of the sprinkler system.

NB if it is a stack of idle pallets this constitutes a very high risk and the height of the stack will be limited.

[Alec]

I believe the starting point for the clear space that is to be maintained below the roof space is 0.5m. For high-piled combustible stock the clear space should be increased to 1m or more, and for stock in rack sprinkler systems, the clearance is 150mm.
Well that is what I have in my memory bank, dont quote me on it though until I can pull out the regulations.

[kurnal]

Depends Alec. You are right if you are talking about OH sprinklers under the old codes but for higher hazard storage sprinklers of all types - XHH or HHS or EFSR  or under latest FM rules "Storage Sprinklers" have always required 1000mm or 900mm or 3ft depending on which version of the code you are using.

For in rack heads yes its still 150mm below the heads in the racks

[Phoenix]

In warehouses what distance should stock be stored from sprinkler head?

A question I was asked but don't have an answer other than point to the relevant standard even though its not about installation, but where to stack the pallets.

When you say that this is a matter of "where to stack the pallets", do you mean that someone is stacking pallets in an area that does not have a sprinkler installation that was specifically designed for such storage?  Pallet storage has its own guidance.  When kurnal says that the storage of idle pallets is "very high risk", what he means is that they possess a high fire load in a configuration that will accommodate very rapid fire development.  This is why they need a lot of water and why a sprinkler system that is not designed to meet the needs of the situation may not be able to contain a fire.

TB215 addresses the issue and Table 2 of 12845 gives max height of sprinkler deflector plates above the top of the stock.  Otherwise at least 1m clearance as kurnal says.

Stu

[Tom Sutton]

The questions I get from Joe public are simple "In warehouses what distance should stock be stored from sprinkler head?" They have little insight into how complicated Fire Safety can be, especially when dealing with specialist subjects like sprinklers. Consequently I never give definitive replies simply point them to guidance that may help however sometimes I would like to know the answer myself and help them further if possible. http://www.safelincs-forum.co.uk/

[kurnal]

Thats fine Tom but sometimes a simple answer to their question like this creates the wrong impression. Sorry if I overcomplicate things - and I accept I often do- but with sprinklers the context of the question is absolutely vital.

For a simple question "how close can  I stack to the heads". If the questioner simply wants to know the dimensions of the clear space that must be maintained beneath the deflector thats fine. Simple question simple answer.

But in my experience its more commonly asked in the context of wanting to stack stuff up to this level and then the simple answer is fraught with danger and I agree with you- the safest response is to point them towards guidance. And hope they read it.

[Tom Sutton]

I fully agree with you Kurnal maybe I should have used the word "simplistic" They ask what they most probably see as a simple question and expect a simple reply but as you know, very rarely there is a simply answer, especially when dealing with specialised areas.