When and where to retro fit fire clips if at all

Daniel S Robinson said:

Following the release of the new best practice guide 4 in March 2025, I see the C3 option has been removed for cables not supported against premature collapse, now there is only a C2 option.

It is only a guide.

Daniel S Robinson said:

but some of the trunking is that old and brittle it would break if you remove the lid.

So past its sell-by date in any event.

Hi Chris you raise a good point around the brittle trunking, maybe we need to replace it any way.

for retrofit over odd shaped trunking etc. 
https://www.tlc-direct.co.uk/Products/FXBAND12W.html

No need to paint this builders band, it is already made painted white like that.
A bit of practice with tin snips and bending it round a bit of wood the right size means you can prefabricate a few top hat shapes while at ground level, then when installed they all look the same size and profile.
A pair of white screw caps either side complete the look.
https://www.screwfix.com/p/essentials-6-8ga-100-pack-white-polypropylene-screw-caps/88327

The fact that the cap softens in a fire, like the trunking it holds up, is not a structural matter so long as the screw head will not pass through the holes in the band.  Been seeing this sort of thing for quite a while now...

Mike

The phrase “only a guide” would relate to many documents including BS7671, however Electricity at Work Regulations 4,6 and potentially others would be applicable. Guidance serves as a way to comply with law and should be treated as such. Best Practices Guides are industry standard guidance and a consensus of experts and recognised in legal cases, therefore would be the applicable information to help comply. Without guidance, the industry would be a Wild West of people’s uncoordinated opinion. 

I concur

But, none the less the  use of advice in a guide or standard, without the application  of any associated thought, does not guarantee a good job, nor does in confer immunity from all liability.
By all means refer to the advice, but part of that process is to understand when it does (and also does not) apply. There is an important difference between BS7671 and a cookery book.

Mike

But, none the less the  use of advice in a guide or standard, without the application  of any associated thought, does not guarantee a good job, nor does in confer immunity from all liability.
By all means refer to the advice, but part of that process is to understand when it does (and also does not) apply. There is an important difference between BS7671 and a cookery book.

Mike

I follow the late Michel Roux to the letter, but generally feel free to modify recipes.

The point is that a guide is never more than an expert opinion, even a committee of experts. It may be persuasive in a court, but you still need your expert witness(es).