Put the cables in the cavity,tell no one you did so
Any officious council employee will be none the wiser

He will have the exact measure of wisdom whether he knows or not (regarding cables in cavities)
The measure of his wisdom means he would have no clue of what should be done if he objected in the first place
 
  • Creative
Reactions: Rpa07
I though vertical trunking was required to have cable supports over certain lengths; was there some new reg or update on that in the last amendment.

Just been looking for this, cause I was curious.
We have:

522.8.4 Where conductors or cables are not supported continuously due to the method of installation, they shall be supported by suitable means at appropriate intervals in such a manner that the conductors or cables do not suffer damage by their own weight.


522.8.5 Every cable or conductor shall be supported in such a way that it is not exposed to undue mechanical strain and so that there is no appreciable mechanical strain on the terminations of the conductors, account being taken of mechanical strain imposed by the supported weight of the cable or conductor itself.

Neither of these state a measurement. The only one that does is regards to caravans..

721.522.8.1.3 All cables, unless enclosed in rigid conduit, and all flexible conduit shall be supported at intervals not exceeding 0.4 m for vertical runs and 0.25 m for horizontal runs.
 
  • Informative
  • Like
Reactions: Wilko and Midwest
Thats like wiring a conservatory and putting sockets on the wall attached to the house, they will need to be IP rated incase they ever take the conservatory down.

You can only allow for what is there when installing.

Not really a fair analogy. If you demolish a conservatory, you'll want to remove the sockets and wiring with it. Cavity wall installation is a popular home improvement, ie not unusual. The installers may well be unaware of the cables in the cavity and are unlikely to do anything about it if they are.
 
  • Like
Reactions: DPG and Midwest
The installers may well be unaware of the cables in the cavity and are unlikely to do anything about it if they are.

they wouldn't give a sh*t anyway. bung it in as quick as possible, move on. sod any other trades being compromised.
 
Never a fan of cables in cavities. They will bridge the cavity in multiple locations - this can cause problems and is frowned upon. Traditional wall ties also bridge the gap, but they are designed so that any moisture is dropped down the cavity rather than tracking across.

And, as someone alluded to earlier, how do you support horizontal runs of cable in the cavity? It could be going through for several meters without any support other than where it is sat against the edge of a brick at either end.

And thirdly the issue of all that wall insulation being added at some point to nicely downrate the cable.

Just generally not a good thing to do.
 
And, as someone alluded to earlier, how do you support horizontal runs of cable in the cavity? It could be going through for several meters without any support other than where it is sat against the edge of a brick at either end.

Just out of curiosity, what do you guys do then you put cable in the oval trunking like below?
upload_2018-6-18_15-13-55.png


What max length do you use.
As you see by my earlier post. There is no actual length specified in the regs.
 
Doesn't matter - the tubing supports it??
 
Never a fan of cables in cavities. They will bridge the cavity in multiple locations - this can cause problems and is frowned upon. Traditional wall ties also bridge the gap, but they are designed so that any moisture is dropped down the cavity rather than tracking across.

And, as someone alluded to earlier, how do you support horizontal runs of cable in the cavity? It could be going through for several meters without any support other than where it is sat against the edge of a brick at either end.

And thirdly the issue of all that wall insulation being added at some point to nicely downrate the cable.

Just generally not a good thing to do.

So how do YOU pass a cable through a wall with a cavity in it?
 
So how do YOU pass a cable through a wall with a cavity in it?

No problem going through a cavity wall with any cable. It's long runs of cable run within the cavity I dislike.
 
Just out of curiosity, what do you guys do then you put cable in the oval trunking like below?
View attachment 42847

What max length do you use.
As you see by my earlier post. There is no actual length specified in the regs.
Hi - well, it's just used for drops from ceiling, so typically less than 3m, and there never seems to be any issues.
Just for some fun (still sick today:( ) - I did see some data saying soft copper could take a static load 15N /mm2 without damage (internet source, so not sure if correct). Now 1mm twin and earth would be 3mm2, so about 4.5kg max static load. But for safety, let's assume only 1 core takes all the load and for further safety divide my internet number by 2, that's about 750gm loading, not much! But I get 1m of Prymesian's finest 1mm twin and earth to weigh in at 60gm, so 3m of it seems fine for hanging undisturbed in the conduit. Hopefully :) .
 
  • Like
Reactions: Wilko
Regarding the length of unsupported vertical cables, the OSG gives guidance of no more than 5m with adequate support at the top and states this should satisfy the requirements of 522.8
 
  • Like
  • Informative
Reactions: DPG and Spoon

Similar threads

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Electric Underfloor Heating Electrician Courses Heating 2 Go Electrician Workwear Supplier
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc

Advert

Daily, weekly or monthly email

Thread starter

mattg4321

Arms
~
Joined
Location
South East UK
If you're a qualified, trainee, or retired electrician - Which country is it that your work will be / is / was aimed at?
United Kingdom
What type of forum member are you?
Practising Electrician (Qualified - Domestic or Commercial etc)

Thread Information

Title
Meter tails in cavity
Prefix
N/A
Forum
UK Electrical Forum
Start date
Last reply date
Replies
37

Advert

Thread statistics

Created
mattg4321,
Last reply from
Andy78,
Replies
37
Views
15,708

Advert