Thoughts on this scenario?

[JM1TTY]

Im just curious as to peoples thoughts on the following install I seen on a video from an Electrical firm today and they did the following:
Ran power to an outdoor shed by coming off the downstairs ring by coming off one of the sockets with a 4mm 3 core cable to an outdoor socket. They then ran a 4mm armoured cable to the shed and supplied it with sockets and lights i have attached a diagram to make it easier to follow. In my opinion this would possibly cause nuisance tripping due to the outdoor lights possibly having water ingress but also is this acceptable in the regs? You can't spur off a spur due to cable current carrying capacity's which he's obviously done but with the cable being the same or even higher than the breaker where do you stand?

 

[westward10]

4.0 SWA will happily carry 32A so there isn't an overload situation. There is no Regulation to suggest you cannot spur from a spur (an Appendix is informative). Strictly speaking the lights are not outside and in any case they should be selected to suit the installation environment and as such water ingress should not be an issue they should however have some form of local circuit protection subject to a maximum of 16A.

 

[littlespark]

This same scenario popped up on the forum a little while ago.

I’d be cautious of the point on the house rfc where you’re trying to get 2x 2.5 and a 4mm into one terminal.