Thank you all, and quick question

Discussion in 'Irrigation' started by nacarson, Aug 27, 2007.

  1. nacarson

    nacarson LawnSite Member
    Messages: 15


    First of all I wanted to thank everyone for the wonderful advice, material and professional information contained within this forum. Secondly, I apologise for posting and not being a professional, but wanted to tap the advice of some of the gurus here; I hope this causes no offence.

    I am installing a sprinkler system at home. Good design (head to head coverage, proper pipe sizes) and good parts (1800 SAMPRS, 3500 rotors, swing joints, commercial timer etc) much thanks to the topics on this forum.

    Anyhow I just dug my mainline trench (for carrying about 12gpm w/ static pressure 53PSI). I had planned to install 1.25" Sch 40 PVC which over my length will give minimal pressure loss.

    However, I had to go within 1.5ft of an established Ginko tree, and 3ft of a large silver birch (sorry almost typed *****, slip of the finger).

    Those trees have root systems that look like Los Angeles freeway intersections: Giant 4+ inch feeder roots criss crossing. I can just about squeeze the Sch 40 in between... But the tree's gonna grow, and a bit of pressure as the roots grow will break the pipe. In some cases the roots are preventing me from getting the trench quite as deep as I should (only 13" or so).

    I can't re-route, and I'm not comfortable to cut so many main roots, so was thinking of maybe going Galvanized instead for mainline (Type L copper is 7 bucks/foot or something) which will probably hold out much better.

    But I know it corrodes. How long would say some 1.5" galvanized last me for (that way, even if the inside starts corroding, still plenty left before it gets too small)? Heavy clay soil here. Would presumably help avoid the sand backfill (for soil expansion) needed with PVC too.

    Would it last a few decades? Any other ideas (I am not comfortable with poly mainline sorry).

    Sorry if such basic, simple stuff is too trivial for you pros out there.

    Thanks so much

  2. PurpHaze

    PurpHaze LawnSite Fanatic
    Messages: 5,496

    Put the PVC in and don't worry about it. Eventually you will have a break from the trees but it will be much easier to repair with less root damage than if you install galvanized pipe.
  3. DanaMac

    DanaMac LawnSite Fanatic
    Messages: 13,174

    How about PVC mainline in a PVC sleeve, one size bigger? Just a little added protection.
  4. nacarson

    nacarson LawnSite Member
    Messages: 15

    Thanks! That could work, or PVC in a galv sleeve for that matter where it goes through the tree areas. The galv may make it harder to fix later though...

    I'll stick with the PVC then, and double sleeve it in PVC as you suggested! Thank you.

    PROFESSORRAIN LawnSite Member
    Messages: 246

    Try not to have glued joint in sleeve if it were me put sch 40 innthe ground and keep kicking
  6. Kiril

    Kiril LawnSite Fanatic
    Messages: 18,334

    Don't cut the roots, dig in your lines deeper. There should be minimal problems with roots at depths of 2 feet or more, especially with birch.
  7. nacarson

    nacarson LawnSite Member
    Messages: 15

    Thanks Kiril et al

    I did in fact dig a few more inches down. With the mattock and spade in heavy clay, couldn't bring myself to go to 2ft+ though. Overall, going past 3 large trees, I ended up cutting one roughly 1" root, and crossing 9+ others, some really big. In one place where I went close to some roots, I put an extra sleeve around the pipe too.

    The Sch 40 is tougher than I first imagined - so I think it'll be fine. The mainline's now pressurised with valves on, so I am pretty much done with it - next onto the poly laterals (which I will probably raise above roots).

    Thank you!
  8. Kiril

    Kiril LawnSite Fanatic
    Messages: 18,334

    You would be surprised at the damage roots can do to PVC. My suggestion, avoid fittings at all costs in areas around roots.

    PROFESSORRAIN LawnSite Member
    Messages: 246

    I'm with him^
  10. nacarson

    nacarson LawnSite Member
    Messages: 15

    Yep, no fittings within a foot or two of roots (as good as I can get). The closest roots have at least 2 inch gap betwen them and the pipe.

    Seems about as good as I can do, without starting a mining operation.

    Don't know how you guys zooming around with your pipe pulling machines know what you're going through down there...

    I'll post some pics when it's all up and running :)

Share This Page