Electricity cables in cavity next to door frame
- Thread starter WelshEmz
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Not ideal, but not against the electrical regs.
Bridging the gap is more of an issue
Bridging the gap is more of an issue
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wiki has the rules but not sure what is building regulations and what is electrical regulations the latter is not law, but can be used in a court of law.
It says at the bottom of Wiki page
It says at the bottom of Wiki page
Yet there are special skirting boards designed to run cables in, also dado trunking the same, so it seems there are exceptions to the rules not quoted.
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It does, but it doesn't cite any source for said claim.
My understanding is there is nothing special about skirting boards per-se, it's just that there is no "safe zone" at the bottom of a wall.
However, safe zones only apply to cables "concealed in a wall or partition" at a depth of less than 50mm. A cable clipped to the surface is not concealed and cables run in what is obviously conduit or trunking are not generally considered to be concealed either.
Where things get more dubious IMO is with hollow wooden skirting products that are designed not to look like electrial trunking, or when mini-trunking is caked in thick paint such that you can no longer tell that it is mini trunking rather than decorative wooden trim. I guess you could argue that they are not "in" the wall but
Most of the rules for cables concealed in walls/partitions only apply to cables less than 50mm deep. A standard brick is more than double that so a cable in the cavity of a brick cavity wall is not required to follow "safe zones" or be RCD protected.
That said, there are other concerns with running cables in cavity walls, which lead to the practice being generally frowned upon.
1. What is the "installation method" for cable rating purposes? If it's an unfilled cavity wall it's probably fine, but if the wall is filled with insulation either immediately or later then the cable may overheat unless a significantly larger than normal cable is used.
2. Unless clipped in place, there is a good chance that the cable touches both the inner and outer walls. As such there is the possibility of it acting as a "bridge" carrying heat or moisture between the inner and outer skins. I question how much of an issue this is in the real-world though.
That said, there are other concerns with running cables in cavity walls, which lead to the practice being generally frowned upon.
1. What is the "installation method" for cable rating purposes? If it's an unfilled cavity wall it's probably fine, but if the wall is filled with insulation either immediately or later then the cable may overheat unless a significantly larger than normal cable is used.
2. Unless clipped in place, there is a good chance that the cable touches both the inner and outer walls. As such there is the possibility of it acting as a "bridge" carrying heat or moisture between the inner and outer skins. I question how much of an issue this is in the real-world though.
True, but I suspect 'no worse' than the "ties" that are required to be installed between inner and outer leafs of a cavity wall?
However,as you say, a cavity full of insulation would be a different matter (in terms of the cable's CCC. It's probably unlikely that anyone would be able to get cable into a cavity already filled with insulation but, as you imply, insulation might be added ('injected') after the cable was installed.
It is totally illegal to run cables in cavity walls as there are still quite a few cavity insulations that dont have a fire ratting. Especially the blown in types. Some do, but many dont.
Rubbish.
Its not electrical regs, its building regs & bad practice.
There is no electrical regulation that forbids an installer installing a cable within a cavity wall. However BS 7671, The Building Regulations 2000 for England and Wales (2004 edition) and Mandatory Standard 3.10 of the Scottish Building Regulations highlight a number of reasons why this practice is undesirable:
The cable may be damaged during installation - Reg 522.8.1 refers
The cable lacks support and also damage may occur due to the cable's own weight - Regulation 522.8.4 refers
Thermoplastic insulation (PVC) in contact with polystyrene may cause the plasticizer within the insulation to migrate, leading to softening of the cable sheath - Regulation 522.5.3 refers
Cables installed within thermal insulation will have their current carrying capacity significantly reduced, which may require cable sizes to be increased - Regulation 523.7 refers
PVC cables are more prone to attract dampness
The cable may be in contact with the outer and inner wall thereby providing a route for water - Approved Document C Building Regulations
A route for precipitation might be provided where a hole exists from the outer wall - Mandatory standard 3.10 Scottish Building Regulations
Due to these reasons the installation of cables within cavity walls should be avoided.
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Which is it?
Read above.
its definitely NOT illegal
OK, but if i was the builder i would kick the sparky off site. There are lots of guide lines although not a rule, for good reason.
That is just laziness.
That is just laziness.
So - you were wrong.
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