John Rumm wrote:

Richard J. wrote:

While investigating some dampness in my kitchen walls, we found that the
previous owner's builder, when extending the kitchen in 2000, had
embedded a T&E cable for a radial circuit in the concrete floor screed
without a conduit and only about 10 mm below the surface. I believe
they are supposed to be at least 50 mm and in conduit. Would this have
been illegal at the time, or merely foolhardy?


IIUC there is no specific requirement for conduit or any particular
depth for cables to be buried at when in a floor (unlike walls where
wires running outside of the "expected" locations must be 50mm deep or
protected so as to be difficult to penetrate with nails etc). There is
however a general requirement that a cable run in a floor "shall not be
liable to damage". As to how liable to damage your cable is/was is a
matter of debate.

So you could say it was not in keeping with the spirit of the regs.
Since they (at the time) had no force of law it would not have been
illegal.


Actually I have in extremis done this myself. Chipped up a bit of floor
to exetend a ring across a doorway.

The spirit of the regulations is to ensure that the normal use of the
property and its electrics do not result in any shock or fire hazard. Up
to and incluing minor work on the property. Ther is also and element of
accessiblity implied in some regulations - e.g. trunking for pipes.

Now T & E in cement is not a fire risk - in fcat its likley to be better
cooled and less surriunded by flammable material than e.g.pulled up
through and insulated stud wwall for example.

As far as shock hazard goes, it is unusual to be drilling into floors to
do anything at all, so the requirements for routing concealed cables are
highly relaxed.

As far as accessibilty goes, again PVC coated cable in screed either
works or it doesn't. Unlike pipes wich can and will corrode in concrete,
it lasts well.

So I personally neither think that it is against regulations, or a Bad
Thing. Its not hard to chip out a section if it finally after years
breaks - certainly no worse than copper water pipes. And frankly with
my floor FULL of plastic UFH water pipes, a couple of bits of T & E is
the least of MY worries.