Stefek Zaba wrote in message ...
jim_in_sussex wrote:

snip

b. if it is legit to just rest cable on the (ordinary) plasterboard,
which IEE regs installation method is this?

Kinda-depends what's resting on the plasterboard! If it's the common
case of the ground-floor-ceiling/upper-floor-floor void we're talking
about, there's usually no insulation, and this is pretty much our mate
Reference Method 1, Clipped Direct.

snip

HTH - Stefek

Yes thanks, but it's the words 'clipped direct' that throw me.
Loosely resting on plasterboard seems a long way from being clipped
every 9 inches to a timber joist.

I had the impression that one reason for clipped direct having a good
current rating was that holding the cable firmly against timber gave
you a reasonable heat sink (possible surrounding insulation being
ignored or assumed not present for the purpose of this discussion).
But I suppose resting on cold p'board might be as good.

Still slightly puzzled, but thanks all the same.