Mains wiring behind skirting?

Post by Matthew
In response to my question about copper pipes in concrete floors
somebody mentioned burying CH pipes behind skirting. As a related topic
what are the building regs (if there are any) regarding putting mains
cable behind skirting board. Is it ok to do it? It would make some of
the house rewiring a lot easier. Obviously using pink grip rather than
nails to hold the boards onto the wall!
Thanks,
Matthew

No, no and thrice no.

The only ways that this would be permissible is either if you bury the
cable at least 50mm below the surface or protect it with substantial
steel plate or equivalent.

In other words, as a convenience solution, no.

--
.andy

Dave Plowman (News)

2006-02-16 18:27:06 UTC

No, no and thrice no.
The only ways that this would be permissible is either if you bury the
cable at least 50mm below the surface or protect it with substantial
steel plate or equivalent.
In other words, as a convenience solution, no.

Not querying your answer, but the reasons behind it. On a wall people will
drill or nail into it for shelves and pictures etc, but into a skirting
board?

--
*How many roads must a man travel down before he admits he is lost? *

Dave Plowman ***@davenoise.co.uk London SW
To e-mail, change noise into sound.

m***@care2.com

2006-02-16 18:59:28 UTC

Post by Dave Plowman (News)

No, no and thrice no.
The only ways that this would be permissible is either if you bury the
cable at least 50mm below the surface or protect it with substantial
steel plate or equivalent.
In other words, as a convenience solution, no.

Not querying your answer, but the reasons behind it. On a wall people will
drill or nail into it for shelves and pictures etc, but into a skirting
board?

Quite. But thems is the regs anyway.

NT

Tim S

2006-02-16 20:00:23 UTC

Post by Dave Plowman (News)

Post by Matthew
In response to my question about copper pipes in concrete floors
somebody mentioned burying CH pipes behind skirting. As a related
topic what are the building regs (if there are any) regarding putting
mains cable behind skirting board. Is it ok to do it? It would make
some of the house rewiring a lot easier. Obviously using pink grip
rather than nails to hold the boards onto the wall!

No, no and thrice no.
The only ways that this would be permissible is either if you bury the
cable at least 50mm below the surface or protect it with substantial
steel plate or equivalent.
In other words, as a convenience solution, no.

Not querying your answer, but the reasons behind it. On a wall people
will drill or nail into it for shelves and pictures etc, but into a
skirting board?

Quite. But thems is the regs anyway.
NT

I'd often wondered that. I'm more likely to screw a wall cabinet in the
corner of a room, right over a permitted zone. Strange...

Tim

Andy Hall

2006-02-16 22:22:43 UTC

Post by Dave Plowman (News)

On Thu, 16 Feb 2006 18:27:06 +0000 (GMT), "Dave Plowman (News)"

No, no and thrice no.
The only ways that this would be permissible is either if you bury the
cable at least 50mm below the surface or protect it with substantial
steel plate or equivalent.
In other words, as a convenience solution, no.

Not querying your answer, but the reasons behind it. On a wall people will
drill or nail into it for shelves and pictures etc, but into a skirting
board?

I know. It is somewhat illogical...

--
.andy

Tim S

2006-02-16 17:00:49 UTC

Hi

Your are not meant to do it in the general case as the cable will be "out of
zone".

Zones are in brief, IIRC, horizontally off a visible accessory (light
switch, socket etc), vertically above or below, or in a 6" wide horizontal
band on the wall, where the top of the band touches the ceiling and
likewise for a 6" vertical band on either side of an inside corner.

So, technically skirting is out, unless it's purpose built trunking and that
usually looks ugly.

However, if you use an appropriate cable type or run with mechanical
protection (eg earthed metal conduit) you can run outside of the zones.
Ditto if it's on the surface, but that's not applicable here.

Suitable cable might include SWA (not much use here), MICC (could be done,
but slow to terminate so expensive to have fitted, harder to DIY and you
*will* need a Megger or similar insulation tester because it's horribly
susceptible to damp if you get the terminations wrong)

Or *possibly* an earth screened cable such as Lapp XL-Shield. There's a BS
number which I forget.

The last cable type won't stop you putting a nail through it, but it will
guarantee the nail is earthed long enough to trip the overcurrent
protection. I've considered this myself for a similar situation.

Only drawbacks are - it's expensive, hard to get, TLC sell it in a subset of
manufactured sizes - and it's specified as it must be installed with a Type
B breaker as the overcurrent protection and the circuit must have a
prospective short circuit current not exceeding 6kA. Probably not a problem
unless you live on top of the substation, but would need to be proved in
any case.

XL-Shield looks pretty good stuff - no special terminations needed.

This is really just for ideas, you ought to get a qualified person to
confirm your final choice, 'cos I'm not...

HTH

Tim

Richard Conway

2006-02-16 17:03:00 UTC

Not allowed I'm afraid.

m***@care2.com

2006-02-16 18:11:22 UTC

certainly makes life easier, but no longer regs compliant. If you get
sheet steel and glue it to the back of the wood before fitting the
skirting, youre all compliant.

NT

Tim S

2006-02-16 23:10:03 UTC

certainly makes life easier, but no longer regs compliant. If you get
sheet steel and glue it to the back of the wood before fitting the
skirting, youre all compliant.
NT

IMO that is only valid if the steel is thick/hard enough to stop
a nail or a drill from penetrating - or - the plate is earthed.

Otherwise you just might get a live nail/screw and plate to boot.

Cheers

Tim

m***@care2.com

2006-02-17 11:27:41 UTC

Post by Tim S

Post by Matthew
what are the building regs (if there are any) regarding putting mains
cable behind skirting board. Is it ok to do it? It would make some of
the house rewiring a lot easier. Obviously using pink grip rather than
nails to hold the boards onto the wall!

certainly makes life easier, but no longer regs compliant. If you get
sheet steel and glue it to the back of the wood before fitting the
skirting, youre all compliant.

IMO that is only valid if the steel is thick/hard enough to stop
a nail or a drill from penetrating - or - the plate is earthed.
Otherwise you just might get a live nail/screw and plate to boot.

only true if the OP were dense enough to put wires there then nail the
skirting on! And I dont believe he is.

NT

Tim S

2006-02-17 12:38:33 UTC

Post by Tim S

certainly makes life easier, but no longer regs compliant. If you get
sheet steel and glue it to the back of the wood before fitting the
skirting, youre all compliant.

IMO that is only valid if the steel is thick/hard enough to stop
a nail or a drill from penetrating - or - the plate is earthed.
Otherwise you just might get a live nail/screw and plate to boot.

only true if the OP were dense enough to put wires there then nail the
skirting on! And I dont believe he is.
NT

Indeed - which brings us to the interesting question:

What *is* trunking? Can skirting adapted to fit onto battens with clips
for example be considered as trunking?

Not that I'd go down that route, it would be too hard to argue the point
with an installation inspector.

I still believe that cable behind skiting is OK, *provided* that he uses an
appropriate cable type, being one with suitable internal protection.

I had several responses on the IEE forum when I queried this, that foil
screened cables to BS8436 were OK outside of the zones with no additional
mechanical protection. I correct one point I made - some of those cables
require a prospective short circuit current of no more than 5kA,
not 6kA as I previously wrote.

Or heavy gauge earthed steel conduit if there's room and he can be bothered
with the expense/difficulty of fitting it - that you can do what you like
with.

Here's a link to another make of screen cable which explains a lot:

http://tpwcc.com/flexishield.html

Cheers

Tim

Alistair Riddell

2006-02-16 22:58:12 UTC

Seen it done before using metal conduit - it's perfectly OK this way as
long as the conduit is properly earthed..

--
Alistair Riddell - BOFH
Microsoft - because god hates us

Matthew

2006-02-17 09:33:01 UTC

Thanks,
I did think that wiring behind skirting was forbidden so I will go
under the floor. It is interesting though (somebody else has already
mentioned this) that you are far less likely to put fixings in skirting
rather than in a standard plaster wall!

u***@isbd.co.uk

2006-02-17 10:40:37 UTC

Post by Matthew
Thanks,
I did think that wiring behind skirting was forbidden so I will go
under the floor. It is interesting though (somebody else has already
mentioned this) that you are far less likely to put fixings in skirting
rather than in a standard plaster wall!

Yes, but skirting is most often (in my experience anyway, of older
houses) fixed by masonry nails which would not do a cable behind any
good at all.

--
Chris Green

Dave Plowman (News)

2006-02-17 12:13:21 UTC

Post by u***@isbd.co.uk
Yes, but skirting is most often (in my experience anyway, of older
houses) fixed by masonry nails which would not do a cable behind any
good at all.

Well, if putting cable behind I'd expect you to take the usual care when
fixing them back. A bit the same as fixing floorboards with pipes
underneath.

BTW, most older houses don't have the skirting fixed with masonry nails.
They're usually cut nails going into wood wedges driven between brick
courses.

--
*Windows will never cease *

Dave Plowman ***@davenoise.co.uk London SW
To e-mail, change noise into sound.

Dave Plowman (News)

2006-02-17 10:45:24 UTC