Smoke/Fire sealing behind DB

[DaveS79]

Happy Monday people

Am wondering how most of you go about achieving adequate smoke and fire sealing with cables entering back of DB and going up into plasterboard. My understanding is that any smoke/fire generated from inside DB needs to be adequately sealed as not to spread into voids. The DB am changing over just has cables entering straight into it with rather big hole in plasterboard behind it and no sealing. Anytime I have worked on new build flats aswell from my memory they have never seemed to do this either. Have bought some fire sealant foam to apply around cables and seal the hole but this does seem like it would be pain in arse in future should cables need to come out or new ones in. Also probably won't be the neatest. Cheers

 

[Andy™]

the reg regarding non combustible simply states the enclosure shall be non combustible... make no reference to fire sealing any holes

 

[DaveS79]

the reg regarding non combustible simply states the enclosure shall be non combustible... make no reference to fire sealing any holes

Thanks Andy. So is there no reg saying need to seal board for smoke that may be produced aswell and enter voids. I suppose there probably isn't as any electrical switch/socket would need this also

 

[Doc Hudson]

I get confused with these types of questions, as any person installing a consumer unit should be competent with sufficient knowledge and a copy of, (or access to a copy of),  BS7671 wiring regulations. So from your knowledge of BS7671 which regulation is it that you think you are trying to comply with?

Doc H.

 

[DaveS79]

I get confused with these types of questions, as any person installing a consumer unit should be competent with sufficient knowledge and a copy of, (or access to a copy of),  BS7671 wiring regulations. So from your knowledge of BS7671 which regulation is it that you think you are trying to comply with?

Doc H.

In all honesty Doc. The fact I'm posting this question means I'm doing my upmost to comply with regs and so leave a safe install. If there is nothing you ever queried or sort clarity around fair play to you. But I would rather leave an installation knowing I left it safe rather than be embarrassed to look like a doughnut at times. Truth is I don't always find regs a very easy read...although I have referred to them in regards to fire/smoke sealing and from what I can see I do not need to be concerned in this scenario. I can only learn through my opportunities for experience and how I have witnessed other people's installs and this has confused me as at times have seen cables completely foam sealed entering DB from the behind plasterboard and I have also not seen it. Hence why I asked for clarification as I could not see any mention of similar situation in regs ie 422.4, 422.5 and 527 which deals with sealing cables within containment it is in to the same fire rating as any room/building structure that it passes through. Thanks if anything you prodded me to atleast re double check regs

 

[binky]

not seen anything about smoke! I have seen some boards on new build flats where the rear entry has been sealed, but I think the requiremnt is more to do with the structure of the building, plus, many architects do not understand regs so over spec many things.

 

[DaveS79]

not seen anything about smoke! I have seen some boards on new build flats where the rear entry has been sealed, but I think the requiremnt is more to do with the structure of the building, plus, many architects do not understand regs so over spec many things.

Thanks Binky. Yeah I can't see anything in regs regarding sealing for smoke. I've seen it in certain properties and think your right more likely to be to do with design/construction of building i.e large voids between floors or higher risk of fire spreading due to materials used. That or designers clueless and playing it safe 

 

[binky]

sometmes sealing is for acoustic reasons, or possibly even energy ratings to pass pressure testing required these days for Building Control.

 

[DaveS79]

sometmes sealing is for acoustic reasons, or possibly even energy ratings to pass pressure testing required these days for Building Control.

Never considered that 

 

[NozSpark]

sometmes sealing is for acoustic reasons, or possibly even energy ratings to pass pressure testing required these days for Building Control.

or to reinstate a fire barrier between fire compartments in flats.... however a standard house is a single fore compartment (unless it has an integrated garage), so wouldn't require it