Fire Resistance between sprinklered and non sprinklered areas.

[K Lard]

Anyone know the recommended fire resistance between sprinklered and non sprinklered areas within the same building e.g. offices and warehouse?

[kurnal]

In my day Sprinkler codes generally recommended a minimum of 1 hr but of course there may be other considerations such as building regs and insurance company aspirations. If you ask them they always asked for 4 hours and needed a good telling off.

[Fishy]

BS EN 12845 states that the fire separation between sprinklered & non-sprinklered areas... "shall have a fire resistance specified by the authority but in no case less than 60 min. Doors shall be self-closing or be closed automatically in the event of fire".  As Kurnal says, if the sprinklers have a non-life safety function then there may be enhanced insurers' requirements.

The other thing that's often forgotten is that 12845 also says you shouldn't normally have sprinklered areas located above non-sprinklered areas.

[Phoenix]

What kurnal and Fishy say, plus...TB206 in the LPC Rules gives guidance on this but different organisations follow this to different extents.  Building control will often be satisfied with whatever level of FR is recommended for that part of the building under ADB or 9999 but insurers are more likely to look for the full level of FR as recommended in TB206.  It can depend on the objectives of the sprinkler installation, on why it is being installed.  Is it for compartment sizing, for extended travel distances, for short boundary distances, for simple property protection, to complement a smoke control system, for building height?  Nothing's ever easy, is it?!

[colin todd]

If it was easy, professionals would not be paid to resolve the matters.

[K Lard]

Thanks for all the replies, seem to remember back in the 90s that insurance companies wanted at least 120 minutes. I am only giving it as business continuity advice as a fire in an un-sprinklered part of a building could develop to such an extent that once it breaks into the sprinklered part it could overcome the sprinklers in that compartment.

[kurnal]

Thanks for all the replies, seem to remember back in the 90s that insurance companies wanted at least 120 minutes. I am only giving it as business continuity advice as a fire in an un-sprinklered part of a building could develop to such an extent that once it breaks into the sprinklered part it could overcome the sprinklers in that compartment.

As Phoenix point out tb206 gives a range of recommendations and we are all in the business of mitigating the effects of fire. But some of the recommendations in tb206 are unrealistic. Take as an example the recommendation for  4 hours separation (if I recall correctly- not looked at it for a couple of years) between sprinklered and unsprinklered parts of a warehouse. This is not easy to achieve in modern steel framed buildings.

But some insurers jump on it and try to persuade the client to implement it often with all sorts of veiled threats. The fact is that if you ask them how much will be saved on the premium, or whether the premises risk profile will be reduced the answer is always negative. The risk profile is determined by the overall property portfolio.

For this reason one of my clients used to construct to meet building regulations only usually to a 1 hour standard and the insurer grumbled but never refused cover or applied any special sanctions.

The water infrastructure for a sprinkler system is generally designed to provide cover for one hour.