Cables and cavity walls

[diyterry]

If I want to run a cable up a cavity wall is it best to run it through the cavity or chase the wall out and run it through a conduit.

 

[westward10]

How can you chase a cavity wall.

 

[telectrix]

How can you chase a cavity wall.

all depends on whether the cavity wall is a fit young female cavity in a miniskirt.

 

[Spoon]

If I want to run a cable up a cavity wall is it best to run it through the cavity or chase the wall out and run it through a conduit.

What distance are we talking?
Does the cavity have insulation in it?

 

[westward10]

I understand now, brick wall with cavity.

 

[Octopus]

Cables on external cavity walls are complete no no imho

 

[Midwest]

Cables on external cavity walls are complete no no imho

With some limited exceptions.

 

[Pete999]

Don't give electrical step by step guides to DIYers

 

[diyterry]

What distance are we talking?
Does the cavity have insulation in it?

About 2m, no insulation in the cavity.

 

[Michael Sands]

Think you are only allowed 3m unsupported in a cavity or vertical duct but it all depends on insulation type for example styrene would degrade cable so probably best to chase so limiting damage when pulling in etc I could go on forever but whoever does job would decide on the job what’s best taking all factors into consideration this would take into account damage to decor and how expensive it would be to put right

 

[diyterry]

Cables on external cavity walls are complete no no imho

Can I ask why?

 

[Octopus]

Can I ask why?

Not supported, bridging the gap ..........

 

[diyterry]

T

Not supported, bridging the gap ..........

Thanks

 

[telectrix]

Not supported, bridging the gap ..........

so what about cavity wall ties???

 

[Toneyz]

so what about cavity wall ties???

They are designed so the water drips down the cavity and doesn't bridge Tel.

 

[Deleted member 26818]

There’s no prohibition in BS7671 against running cables in cavities.
In fact BS8436 cable is designed for use in building voids and BS7671 lists installation methods 40 to 44 as being writhing building voids.

 

[Midwest]

There’s no prohibition in BS7671 against running cables in cavities.
In fact BS8436 cable is designed for use in building voids and BS7671 lists installation methods 40 to 44 as being writhing building voids.

Can imagine anything (other than SWD) wanting to be in a writhing building void.

Would this be the sequel to cables in cavity walls thread part 5, discussion.

 

[Deleted member 26818]

Think that was meant to be within?

 

[Spoon]

I was thinking about @Michael Sands post above, about max cable length, so I went searching.

BBB - page 308. 721.522.8.1.3 states max length of 0.4 m between cable supports.
I can't find anything else in the BBB relating to the max length of cable between supports.

OSG - page 139 (g) states max length of 5 m between cable supports.

 

[Deleted member 26818]

Does the OSG reference a Regulation?