Conduit could be any component or material that allows something else to pass through it.

In landscape contracting we’re most commonly using conduits made of PVC, but poly pipe (polyethylene) can work well too.

The rigid, Sch. 40 PVC pipe shown in this picture is most often used for electrical wire –  like  THHN conductor wire that cannot be buried directly in the ground.

However, there’s no reason you can’t run other types of wire (and things) through this conduit too.

Rigid PVC conduit like this comes in various diameters along with numerous types of “fittings” and connectors to accommodate most any situation.

With a combination of these fittings and special PVC glue you can create a sealed environment to protect the wires and splices inside.

Earlier I mentioned the use of poly pipe as a conduit.  I’m referring to the black poly pipe used in underground sprinkler work.

Poly Pipe – Handy, Cheap and Effective

If your a landscape contractor, odds are good you have this kind of pipe on-hand.  Perhaps you do sprinkler systems as part of your service offering.

At the very least you should have it on hand for:

  • Repairs –  You’d have to call yourself supernatural if you’ve never broken a sprinkler line during a dig-operation. 🙂
  • Sprinkler Modification –  It’s inevitable that an existing sprinkler head has to be moved because of a new plant or hardscape install.  Or how about an underground poly pipe running right where “something new” has to go.  You’ll need to piece-in an additional section to go around the new feature.
  • Conduits –  Poly pipe provides a cheap and effective conduit for many situations.

In the picture above we’re using poly (sprinkler) pipe as a conduit for our low voltage lighting wire.

We installed these poly pipe “runs” early on in the project at a particular time when other utility trenches were open and final grades were not yet established.

To do this it’s important you have a detailed landscape plan that illustrates:

  • light fixture and tranformer locations
  • specific, calculated cable runs
  • locations of all other proposed features and elements

With this information you can safely locate your conduit without fear of running into it later on.

In the above pic notice how pipe ends are bent over to insure dirt does not enter.

The colored marking tape tells the story as to which pipe goes where and what it’s for.

Write down the “color-key legend” on your plan.  When the time comes to pull wire through these conduits, you’ll know exactly which conduits do what.

These simple conduit runs can save you headaches, work and money if you think creatively and strategically, especially in the early stages of your project.

We actually installed additional conduit runs for speaker wire that would be pulled through in the future for rock speakers.

  • james
    6:25 PM, 22 August 2016

    What size poly pipe do you recommend to run your LV wiring in so its easy enough to pull? Whats the max distance that is easy enough to pull without an extra pull point?

    Last question. Do you seal up your poly pipe after your wires are out, so water/dirt does not enter your buried pipe in the future. If so, what sealant do you use?

    • Roger
      11:34 PM, 22 August 2016

      The most common size poly pipe we use is 1″. And I don’t think we’ve pulled further than 100′ in a given situation. Of course that’s not to say you couldn’t. Situations vary. For example, if you plan to run more than one wire through the poly conduit, you pull them at the same time. I can’t remember a situation where we pulled more than 2 wires (12/2 low voltage) through a 1″ poly pipe. Although you could, we like having plenty of room for the wire to get through. And poly pipe is relatively inexpensive. If you need to, just run another conduit alongside.

      The poly conduit is great for direct burial cable. You really don’t have to worry about a closed conduit system like glued PVC for non-direct burial wire. Inevitably we’ll have extra pull points, junctions and turns where we don’t worry about fittings and closed ends. You asked what you could use to seal up points like this. If you feel it’s necessary (in a given situation — and you may) I’d use a good quality duct tape.

      Let me end with this: It’s never easy to come back later and pull an extra low voltage wire through an existing poly conduit with existing wire(s). If you have any notion you’ll need an extra wire, add it with the others from the start and mark it as such. And/or: add another poly pipe conduit and leave it empty (as a spare).

  • Al Mac
    2:06 PM, 6 November 2018

    This may be obvious for contractors, but may not be for DIYers.
    It is very easy to run cables through conduits using a vacuum cleaner.
    Just use a string (like a leveler string), tight a small piece of fabric to one end (small enough to run through the conduit without getting stuck in the middle). Insert the piece of fabric (with the string attached to it) to one end of the conduit. Then on the other end of the conduit, attach the suction tube of the vacuum cleaner. Turn on the cleaner and the fabric will rush through the conduit into the vacuum cleaner. Of course, you have to calculate the distance of the string or pay close attention to detect when the fabric is about to get to the other side of the conduit, then prevent the fabric from getting sucked all the way into the cleaner. Then you just attach your cable to the other end of the string and pull your wire through the conduit. It is a lot easier done than explained here.

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