Depth for electrical cable outdoors

[cdorling]

Hi, I want to run some cable from my house to the bottom of the garden where I will soon (I hope) have a new greenhouse. I'll get someone in the do the electrical bits, but in preparation I want to dig a trench for the cable to lie in. The top half of the garden is (and will be lawn). The bottom half is lawn but will soon be patio (sand + slabs). I've had a quick test dig, & I can get down to 40cm fairly easily but then its solid chalk (Sussex). So..

1) Will the pro consider 40cm to be deep enough under the lawn? Or do I need to buy a pickaxe, and go deeper?

2) And under the new patio, can it just be buried a bit below the sand (20cm ish)?

3) Also, will the cable be able to take lights, lawnmower, g/house heating & pond (but not all at once!)?

Many thanks.

 

[andy]

1: it should be 450mm deep. so you dont have to go much into the harder stuff

2: it may be patio now, but it might not be in future. make it 450mm deep.

3: cables comeisvarious sizes. let your electrician recommend the best size cables for what you want

 

[Softus]

Hi, I want to run some cable from my house to the bottom of the garden where I will soon (I hope) have a new greenhouse. I'll get someone in the do the electrical bits, but in preparation I want to dig a trench for the cable to lie in. The top half of the garden is (and will be lawn). The bottom half is lawn but will soon be patio (sand + slabs). I've had a quick test dig, & I can get down to 40cm fairly easily but then its solid chalk (Sussex). So..

1) Will the pro consider 40cm to be deep enough under the lawn? Or do I need to buy a pickaxe, and go deeper?

Not quite sure why you're asking us to predict what your electrician is going to say - why don't you ask him/her?

2) And under the new patio, can it just be buried a bit below the sand (20cm ish)?

Almost certainly he/she will say no.

3) Also, will the cable be able to take lights, lawnmower, g/house heating & pond (but not all at once!)?

Almost certainly he/she will say yes, and also stipulate armoured cable.

Can't help wondering what's going to terminate the cable at the end of the garden. Is there an outhouse/garage their in which you're going to house some switches for these appliances?

 

[cdorling]

Thanks for replies. Not so much digging at one end then, but more at the other!

(Softus, I want to get a trench dug, then get the electrician round and say I want to go from A to B, trench is dug, how much?).

 

[Softus]

Thanks for replies. Not so much digging at one end then, but more at the other!

(Softus, I want to get a trench dug, then get the electrician round and say I want to go from A to B, trench is dug, how much?).

Okaaaay. So A is the consumer unit, but B can't be mid-air. Is B another CU?