Fire alarms in semi-agricultural buildings

[Guest Andy]

An agricultural barn on the site of a once working farm (no livestock there now), is now the workplace of three members of staff, based in a mezzanine office within the barn, which houses tools and equipment used in land-management.  There are suitable containers storing chainsaws etc and an external fuel store, which provides correct flam-bank storage for the small amount of diesel stored on site <20L.   Must they have a bell, manual call point or some means of raising the alarm (there are neighbouring traders, a car repair workshop, carpentry workshop each side of the barn) or will it suffice that they 'shout' a warning?

[AnthonyB]

It depends! Is there are party wall separating the adjacent neighbours thus providing compartmentation that negates the need to consider them or is it less substantial?

If the shout (or air horn, whistle, rotary gong) can be heard throughout the barn readily you may not need a manual electrical system (call points, sounders, control panel). 

The other consideration would be if a fire could develop unseen and prejudice escape, for example if all the staff were in the mezzanine office. In which case automatic detection would be needed  - if the barn is large enough to need an electrical manual system then you'd add the detectors to this, if not then a fire risk assessor may justify the use of mains powered interlinked domestic smoke alarms (BS5839-6 Grade D) with detectors to the risk areas and office (the latter to act more as an alarm sounder more than a detector) although technically only commercial alarm systems (BS5839-1) should be used.