Hi,

I've been reading many of the threads regarding shed or greenhouse
electrics, but I'm still not 100% on the way to go, so I thought it
best to clarify some things before I proceed.

I have a split-load consumer unit. From the CU to the outside of the
house it approx 8m. From the outside of the house to the brick built
shed it is approx another 8m. I am planning to have a double socket
and a light. The double socket will be used for the occassional use of
a power tool such as a jigsaw or a lawnmower (about 2000w max). The
light will be a standard 100w. Also I plan to power a water feature (2
metres from shed, 25w), a pond pump (15m from shed, 25w), a security
light (500w) attached to the outside of the shed and also have a
single waterproof socket (15m from shed, by pond) just incase I need
to plug something in at the top of my garden.

My questions are (sorry there are a lot of them) :

1. I'm going to use a spare 20Amp 'B' type MCB on the non-RCD
protected side of the CU using 4mm T+E cable. Can I use normal T+E
cable for the first 8m (up to the outside of the house) and then
connect it using a junction box, to 8m of SWA 4mm cable to the shed?

2. I was planning to place the RCD spur unit inside the shed at the
end of the SWA cable. Can I then continue the radial circuit using
normal 4mm T+E or could I use a Fused Connection Unit after the RCD
and continue with 2.5mm T+E?

3. Can I use a plastic back box for the double socket or are there
special 'shed' style sockets?

4. I have estimated a total of 10m of cable being used inside the
shed. Does this have any impact of whether I should use a separate
earth rod or can I just connect the power to the house earth?

Just so you know, I was going to spur to use a 5amp FCU for the shed
light and the security light. Also, all the outside cabling is SWA and
will be in that 20mm blue plastic piping that you can buy from Wickes,
buried deep deep underground.

Thank you in advance!

Paul