[![I would like to run a 25' underground uf cable to power a fountain. The closest outdoor GFI outlet is pictured below.

As the existing outlet is flush with the aluminum siding, I would like to update this outdoor receptacle Can I get one that is made to attach to the old type flush box?


  • It can also be an outdoor outlet that is not GFI, with a GFI protection device upstream of the outlet. If your cable is GFI protected it can be buried at 12" depth, otherwise 24". Jun 1, 2018 at 21:08

1 Answer 1


Weatherproof extension ring is the part you’re looking for.

weatherproof extension ring

They are available in various forms, make certain the model you choose has knockouts.

Sleeve the UF cable in PVC conduit to get it from that point to underground. Since your box is horizontal mount you’ll need an LL or LR or 90 to get from the knockout down into the ground.

  • Note that the OP will want a LL or LR depending on which side of the box they come out of, not a LB (rule of thumb: the access panel on the conduit body needs to face out towards you) Jun 1, 2018 at 22:33
  • @ThreePhaseEel Good point. I debated suggesting a pre-bent PVC 90 and a PVC coupler which is probably the simplest and cheapest—especially for the novice. I’ve seen WP extensions too with knockouts on the long side, but I couldn’t find one today.
    – Tyson
    Jun 1, 2018 at 22:41

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