Our street is getting new water mains and they've pulled up the sidewalks which will eventually be replaced.

I don't have plans for a sprinker system but am thinking I can't pass up putting an empty pipe or conduit under ground before they pour the new sidewalk. I envision an pipe a foot or so longer on each side than the sidewalk buried with the ends taped shut. I'll of course keep a written record of where they are.

What pipe/conduit should I use and how deep should I go? Right now they're filling the 6 foot trench with sand than then topping with a few inches of gravel.

  • 1
    First thing is to make sure the city / county will approve what you plan to do. Sidewalks are often on private property but with legal easements which have specific restrictions as to what the homeowner may and may not do. Jul 3, 2018 at 14:32
  • 1
    It depends on how big the area is that may eventually be irrigated. For the space between the sidewalk and street black sprinkler pipe should be good I think it's 1". Drawback is if it freezes and cracks it's not easily replaceable under the sidewalk. 2" PVC would allow you to slide the sprinkler pipe through and wires for valves if it's large enough to require zones. Jul 3, 2018 at 14:45
  • 2
    If you go to this trouble don't just use tape to cover the ends; glue on end caps that could be cut off later. Jul 3, 2018 at 14:57
  • Depth isn't critical. I'd seek to just keep it out of sight of the city (though they may be cool about it anyway).
    – isherwood
    Jul 3, 2018 at 16:33
  • 1
    if you put it too shallow, then the sidewalk will probably crack along the pipe. i have seen it happen on a driveway.
    – jsotola
    Jul 3, 2018 at 17:05

2 Answers 2


The correct answer depends on a number of variables related to the size of the space and your future landscaping plans. If time permits, you should sketch out a landscaping plan and consult with an irrigation planner to ascertain in-ground requirements according to planned design and water supply.

If time does not permit, follow advice of @Platinum Goose and overbuild with 2" PVC, which would allow you to feed smaller pipes and/or wires through. I would put in at least two (one each end) and glue caps which could be cut off later, as suggested by @Jim Stewart.


I did that when I got my driveway poured .I used 2 coupled 10 ft. lengths of 3/4 " PVC. I put on caps but did not glue them .I buried the PVC about 2 inches in the soil. Worked fine , I came back in a year using 1/2 " PVC in the sprinkler system. Just used adapters to tie in the 3/4 ". I did not need any electric connection at that location.

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.