Tips for running an underground line

Hi:
Due to some remodeling work, I will have easy access to running a buried line from the basement out to a garden area for landscape lighting. Can someone give me suggestions or opinions on the best conduit metal or PVC? I understand that I don't have to use conduit, but it's a short run, so the cost difference shouldn't be a factor.

Second: Can I use a Romex type of wiring (is this UB?) in conduit or do I need unsheathed wires?

Thanks.

 

My first choice would be to skip the conduit, except where above ground. My second choice would be to use PVC. If you are going to run cable through conduit, then use large conduit (at least one inch) to make it easy to get the cable through, and keep the number of bends to a minimum. Do not put the cable in until the conduit run is completely glued together and the glue has thoroughly dried. Then pull it through with the pull cord you put into the conduit, using plenty of pulling lubricant. If you are going to use cable (in conduit or not), then use UF-B cable (which is sold under the Romex brand, but is not what most people think of when they use the word "Romex"). If you're going conduit the whole way, then I recommend simply running individual THHN/THWN wires through it rather than cable.

 

John:
Thanks for your response. Can you further explain why your choices? That is, why is not conduit (except above ground)?

Thanks.

 

Conduit can be a negative because it can be difficult to get UF cable through it without damaging the cable. If you must use conduit, use large enough conduit so that the cable goes in very easily and try not to have bends in the conduit. By all means, don't feed your cable through the conduit as you glue it up. PVC glue eats the insulation on the wire!

I would only consider conduit if you are running this line under the vegetable garden or through some other area subject to frequent digging.