The joists in my loft are less than 100mm in height, meaning that it is
impossible to drill a hole that is 50mm from both the top /and/ bottom
of the joist. I've found other posts that say to run the cable over
the top of the joist and have a baton either side and place steel
strips over the top, e.g.
http://groups.google.co.uk/group/uk....6345a2c9687a7d

In parts the cable/joists will have boards over the top. Can the cable
be run without earthed trunking/conduit? and does this comply with the
building regs? I can't find anything which explicity covers this in
the On Site Guide or the BS7671 Blue Book.

Why not drill through the joists 50mm from the bottom and put 3mm steel
plates over the top to protect from screws.

I beleive this is allowed in the on site guide

Regards - Lightingman

As a slight aside, given the height of the joists will I be able to run
the cables along the length/side of the joists, holding them in place
with cable clips?

"thankyousam" wrote in message
oups.com...
As a slight aside, given the height of the joists will I be able to run
the cables along the length/side of the joists, holding them in place
with cable clips?


This is acceptable, and is the standard way of installing Twin & Earth, PVCI
cables running the length of the joists. If there is thermal insulation laid
"between the joists", the cable should be run preferably, at a height
corresponding to the upper surface of the insulation layer, to avoid
unnecessary cable derating; but in any case, at a height of at least 50mm to
the underside of the cable, measured from the bottom of the joist. (This is
to avoid possible nail damage from below the ceiling).