"Andy Burns" wrote in message
...

wrote:

Self-amalgamating tape may be waterproof amalgamated to itself, but
will it stick watertightly to PVC sheathing to prevent moisture
creeping in?
I think some form of adhesive would be required for certainty

You could use one of the clip on, resin filled swa junction boxes, just
without any actual junction ...

e.g.
https://www.swaonline.co.uk/cable-jointing/cellpack-resin-cable-joint-kits/straight-resin-joint-kit

Not when the nick is so close to the wall.