There is a direct burial electrical cable running from my house to the shed in the back of my garden. This had been put in years ago, was inspected by a certificate electrician and confirmed as correct/valid installation. If I had my ways, it would have been put in a conduit, but it wasn't.

The cable is connected to a separate 30A RCD in the CU in the cupboard, from there it goes under the floor, runs for about 6 meters to the rear wall, and then about another 20 meters direct burial under ground to the shed. It then rises straight into the shed from under the shed's floor and connects to a sub-panel in the shed. In the shed, this powers a light fixture (led flood light - 20W) and a receptacle, which in my 10 years in the house has only been used for electric lawn mower and some hand-held tools (e.g. angle grinder).

The shed has lived its useful life and I will be replacing it soon. When I replace it, I want to put the new shed further away from the house and the existing cable is too short - by about 2 meters or so. What are my options to extend this cable to the new shed location? Ideally, I'd like to keep all of the cable underground, but I'm not sure if a junction box can be buried.

To the best of my knowledge, it's this cable. I am in the UK.

1 Answer 1


In the UK, I think the rules are similar to the US and Canada in that you can't bury a junction box, but you can bury a splice, except in the UK you don't call it a splice you call it a joint.

The hardware used to make the splice / joint must be rated suitable for direct burial. If you search for "resin joint kits," you'll find something suitable, such as the 3M™ Scotchcast™ Resin kit Series 92-NBA.

Since repairing or extending underground cables comes up all the time, I'd be surprised if they were not readily available in local stores.

  • 1
    Ah! That's exactly what I'm after. I tried a quick search for this particular product, but couldn't find it in the consumer shops. There is a specialist electrical shop 5 minutes away from my house - I'll ask there.
    – Aleks G
    Sep 30, 2020 at 11:24
  • 1
    @AleksG you're always better off shopping where the pros do, not the consumer big box stores! ;)
    – FreeMan
    Sep 30, 2020 at 11:40
  • 1
    @FreeMan Agree. I go to the consumer big-box shops for generic stuff as it's cheaper. Anything more serious I get at the "pro" shops usually.
    – Aleks G
    Sep 30, 2020 at 11:42
  • 1
    @AleksG Trouble is then, the pro shops know they only see you with hard problems. The American experience is the big-box shops really take advantage of your loyalty, and their "low, low prices" are mostly mythical. They are just betting that you'll only price-check them on commodity stuff like twin-and-earth. On less commodity things like conduit joiners and 120mm boxes (an actual US size), big-box is twice the price! I've learned never to trust them. Sep 30, 2020 at 16:31
  • @Harper-ReinstateMonica So true! when I said "generic stuff", I did mean that kind of stuff. I am price conscious, but also quality conscious. I don't mind paying more for better quality - within reasons of course. I usually price check almost everything I buy, unless I'm already in the shop and I remember that I need something fairly low-cost.
    – Aleks G
    Sep 30, 2020 at 16:35

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.