Running cables through a cavity

[DNS1]

Just seen someone mention on another thread that running cables in a cavity is bad practice.

Can anyone elaborate for me, I was under the impression that this was ok but not ideal in a new build etc.

How should it be done these days? I'm in a 1990s flat and just wondering how a rewire will be possible without completely trashing ALL the plasterboard!

 

[Guest123]

I believe it's the practice of running cables up/through an external cavity wall, i.e, from an external meter cabinet upward to an internal DB, that is frowned upon as you are bridging the moisture gap.

Also there is no support offered to the cables and they could be subject to damage that you wouldn't be aware of.

 

[goldie]

Agree. Most new builds have cavity walls anyway, When it comes to rewiring we wont be doing it in trunking. Fishing cables down the walls everytime for me, Aslong as its within the zones but i would never run cables down a cavity between the internal and external skin of the building.

 

[mackers]

I believe it's the practice of running cables up/through an external cavity wall, i.e, from an external meter cabinet upward to an internal DB, that is frowned upon as you are bridging the moisture gap.

Also there is no support offered to the cables and they could be subject to damage that you wouldn't be aware of.

sorry to change subject alittle but,as u say lenny bridging moisture gap, how does that relate to the pump in type cavity wall insulation. had mine done 2yrs ago now seem to have a lot of damp. any advice anyone?

 

[goldie]

Is your wall stone or brick type construction?
I have heard that if its of stone type then injecting insulation can create damp spots in the future.

 

[SPARTYKUS]

Agree. Most new builds have cavity walls anyway, When it comes to rewiring we wont be doing it in trunking. Fishing cables down the walls everytime for me, Aslong as its within the zones but i would never run cables down a cavity between the internal and external skin of the building.

Used to be done though, seen a few wired from new like that, all circuits run down the cavities and then through to points. Terrible really, all that cable just hanging on concrete block edges....great holes through to the cavity. Not the way to do it but would struggle to justify that with a reg. common sense over rules!

 

[SPARTYKUS]

Ps refurbed one last year (flood damage) & wrote on cert about it and that its nowt to do with me!!!

 

[goldie]

Its the sky tv man i feel sorry for, when he gets blown off his ladder when drilling through the wall.

 

[mackers]

Is your wall stone or brick type construction?
I have heard that if its of stone type then injecting insulation can create damp spots in the future.

brick mate its proper getting on my wick!

 

[cdavies33]

Ok lads, but how is it to be done on a new build now?? I can be sure of it that all the domestic installers out there aren't carrying 25mm Galv, bushes, end boxes, etc!

So how are they doing it!?!

 

[goldie]

Chop out, or run within the internal cavities, also make use of loft space and under dwelling space. If its solid ceiling and solid floor you can do on surface using decorative coving trunking from above or channel out the floor.

 

[rich.250]

Chase out the wall in the correct zones....
Metal boxes, grommets and oval conduit........
Cables in external cavities does not comply with building regs, is bad practice as previously stated due to lack of support and subject to damage.
Do people not get taught this in apprenticeships?????

 

[Dan the spark]

Ok lads, but how is it to be done on a new build now?? I can be sure of it that all the domestic installers out there aren't carrying 25mm Galv, bushes, end boxes, etc!

So how are they doing it!?!

If it's new build you run your cables in capping to the accessories prior to the plastering/dot and dabbing

 

[Dan the spark]

Beaten to it lol

 

[rich.250]

Me too lol