Does BS 5839-6 or is there a product standard for UK smoke/heat/multi sensor alarm that covers the following?

BS5839, Pt6 is NOT a product standard, rather a code of practice, referenced in the Building Regs. Smoke, Heat + CO alarms

have their own product standards.

Sergio Fernandez said:

Smoke or heat or multi sensor alarm that would be specification suitable of an average UK house for a not frequently visited loft?

Just also note that I see sensors placed above battery installations in loft, which, along with other measures, are claimed to "mitigate in lieu of PAS 63100".

I'm not making any statement about the approach, but considering the detection. Detection of the smoke/vapour for early warning is required for lithium batteries ... the vapour can be heavier than air, so a smoke (or combined smoke and heat) above the battery might not detect ... some people are talking about detection above and below might be necessary.

BS 5446 series covers the standards

BS 5446-1: This part specifies requirements and test methods for smoke alarms, including those that use optical, transmitted light, or ionization technologies. 

BS 5446-2: This part defines the specifications for heat alarms, covering requirements and testing for devices intended for permanent installation in dwellings. 

BS 5446-3: This standard focuses on alarm systems for deaf and hard-of-hearing people, specifying requirements for fire and carbon monoxide alarms and associated warning devices like visual or low-frequency sounders. 

BS 5446-4: This part specifies requirements for multi-sensor fire alarms that use a combination of smoke, heat, and/or carbon monoxide sensors


However does it specify the requirement for when they are in a loft?
- Interlinking.  To allow the alert to be heard through the whole property

- Dusty environment possible thus dust suppression would be a must

- An operating temperature range in excess of -15 to 55°C.  Loft temperature can fluctuate massively from winter to summer in the UK
- Remote Hush/Test button or facility.  There MAY be limited or restricted access into the loft space

Is it possible that BS 5446 series needs to be updated to cater for the scenario of a sensor in the unoccupied/uninhabited loft space?

I agree with the science of a sensor in the loft space and the room below if an inverter or battery or Solar PV array On/In roof were present.  Potential consideration may also be needed for CO (carbon monoxide) alarm as well.  Lithium battery fires can give off carbon monoxide.

Sergio Fernandez said:

a sensor in the loft space and the room below

In terms of "below", I think smoke/vapour above and below in the same room is the proposal?

That could make for an interesting discussion as to the orientation of the particle chamber in the sensor.  

Sergio Fernandez said:

That could make for an interesting discussion as to the orientation of the particle chamber in the sensor. 

Agreed, as well as the position of the sensor.

Gel Jones said:

BS5839, Pt6 is NOT a product standard, rather a code of practice, referenced in the Building Regs. Smoke, Heat + CO alarms

have their own product standards.

Yes, but it's worth remembering that BS 5839-6 actually makes the recommendation for the use of such a detector in this situation ...

The environment can be an issue for the detector in a dusty loft (wouldn't like to put one in mine, 1930s house with lime mortar dust everywhere)

Also where we talking about the Category of the system, the Category becomes "confused" where the original system is a Category LD3 system, if you then interlink a detector in a loft, it's no longer an LD3 system ... but it's not fully an LD2 system either. BS 5839-6 does not really tell us what Category the system is now (even though it's made the recommendation) !

As others have said BS 5839-6 is a code of practice and the installation standard, BS EN 14604 Smoke alarm devices is the product standard for the smoke alarms BS 5446‑2, Fire detection and fire alarm devices for dwellings – Part 2: Specification for heat alarms.