Dave wrote:
Can anyone see anything wrong with this (or suggest a better idea)?
I need to run some tails across the route of some existing gas pipes (at
90 degrees). The pipes are 30mm off the wall so I propose to channel the
wall, run the tails in the channel and add a small piece of something
over the channel to hold the cable in; this will guarantee a 25mm
separation from the pipes - any problem with this?

Should be OK. IIRC just running the cables in insulating conduit or
trunking is itself OK: the 25mm spacing is for cables au naturel (i.e
insulated & sheathed) from gas pipework.

Rememeber 150mm from swicthes etc to gas pipes