3 core flex.

[Bright.Spark]

I'm adding a outside light to an. Existing install. The lights have been wired in an rb4. Can I add my light fitting to the circuit but wire it in 3 core flex instead of 1.5 twin and earth?

 

[ian]

Black is what I would generally use, and to be honest if its outside and is likely to be subjected to temperatures less than 0 degrees I would use artic.

 

[andekoch]

black is preferable since black is generally uv resistant, more so that white.
hi-tuff is very expensive BUT plain NYYJ cable (which is what hi-tuff actually is wen it is at home) is not that bad.
seems like the ideal to me is black pond flex 3183P, cant seem to find 1.0mm cores though. alt seems to be tough rubber 3183TRS.

 

[Wiredspark]

Theres nothing to say flex cant be used outside, but just consider mechanical damage etc

There is no regulation against it and depending on where the outside light and cable run are located may be considered out of reach.