Is my understanding of the requirements around life-safety / emergency lighting (central battery) / fire alarm containment systems in the UK correct with particular reference to BS5839, BS8519 & BS5266.

1. To begin with does each of these systems require it's own dedicated containment system independently supported with both the containment and the supports rated to at least the same as the fire exposure duration of the cable (there's not currently a relevant UK regulation for this so containment and supports have to be manufactured to DIN 4102-12)?
2. Where practicable these containment systems should be the upper-most installed system in the space (where all of these systems are required then they'd be installed level with one another)?
3. To prevent mutual detrimental effects ELV and LV cables on these containments should be segregated? (It's not stated but I expect the most reliable way to achieve this would be to provide separate containment runs rather than a containment divider).

In reality (using cable tray as an example) does this mean I would have a life-safety LV tray, life-safety ELV tray, fire alarm LV tray, fire alarm ELV tray & emergency lighting LV tray (em lighting ELV tray is unlikely). These installed above all other services in the space on a dedicated support system (presumably these life-safety/fire alarm/em lighting trays could share the same support system?)

Also, DIN4102-12 only appears to cover ratings up to 90 min. How is it possible to provide a compliant containment system for enhanced cables that are rated for 120 min fire exposure?

It's been a long afternoon!

Thanks for any input.