Paul,
With respect to a Ring Circuit in a 2-storey house,would there be a ring circuit for each floor?.
Also, with a Spur running off of it, what is the max. loading allowed on a such spur?, assuming that the spur wire is run in the same size wire as the Ring?, is it legal to use a smaller size cable, provided that is fused at a lower current rating, at the tap-off point?. [Linked Image]