This is a follow up to a previous problem I had here: PVC Pipe for sprinkler system broken in multiple places

Does anyone have any suggestions how I can install underground PVC pipe and protect it from Tree roots.

A few suggestions I've thought of are these.

  1. Inserting a 3/4-inch PVC pipe inside of a 2 inch PVC pipe for short distance (10-20 feet). if a tree trunk or root pushes into the pipe and breaks the 2 inch PVC, that should give the 3/4 inch pipe that's inside some protection.

  2. Placing small rocks under, and on the sides, and finally above the pipe. To give it another layer of protection.

Anyone have any other suggestions or think my 2 solutions are bad ones? I'm open ears.

  • I'd be interested to see if there is a way to protect the pipe. Tree roots can lift and break concrete sidewalks. Doesn't seem like PVC stands a chance. Doesn't seem like you want an above-ground system, but what about burying the flexible above ground pipe here?
    – JPhi1618
    Commented Jul 12, 2019 at 20:17
  • @jphi1618 are you talking about the 1/2 inch drip system pipe? Or what? I don't know what you're talking about. Which flexiable above ground pipe? Commented Jul 12, 2019 at 20:23

4 Answers 4


PVC pipe is the most common pipe used for sprinklers, but in areas that require a lot of bends, there is also something known as "funny pipe".

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Funny pipe example

This flexible pipe is not the same as drip irrigation pipe. It is thicker and a slightly different material. Some brands are UV resistant and it can be used above ground in flower beds or in shallow areas where it may get uncovered.

Tree roots may still kink this pipe over time, but the should not break it because it will just bend and flex out of the way.

  • ok, so I was aware of this pipe, but there are 2 big issues. 1. This pipe is rated for only 80 PSI. When the pvc pipe we have is rated for 480 PSI. 2. This is only a 1/2 inch pipe. Our entire system is 3/4 inch. So would this create a bottleneck? Because I would have to downgrade the line. I looked high and low for a 3/4 inch flexable PVC rubber, and found nothing. It's a nice suggestion, but the question is to protect my PVC pipe, not replace it <3 Commented Jul 12, 2019 at 20:41
  • Yea, it was more than a comment, so figured I would just post an answer. The number of heads that run off this stretch of pipe will determine what size you need. If the section around the tree goes on to several other heads, then you may really need 3/4". The PSI rating shouldn't be an issue unless you have very high water pressure. The PSI of SCH40 pipe is way overkill for sprinklers and it's used mainly for its physical strength so it's not crushed. That's not a concern with flex pipe.
    – JPhi1618
    Commented Jul 12, 2019 at 20:46
  • well, it is going to 5 sprinkler heads on the otherside of this pipe repair of 10 total. And I don't know what the PSI rating is. And that's why I went with the SCH40, for the physical strength. Now i'm trying to re-enforce the pipe (somehow) to lesson the chance of breakage in the future. Commented Jul 12, 2019 at 20:49
  • If it's going to 5 heads, I don't think 1/2" pipe is going to work. I think it's a helpful answer for others, and it's one of the things this pipe is designed for. Hopefully someone will have a creative solution for you.
    – JPhi1618
    Commented Jul 12, 2019 at 20:54
  • Toro brand funny pipe is made of polyethylene. There are other kinds of polyethylene tubing made in larger diameters for irrigation as well -- they're just generally called PE or HDPE rather than by a brand name. These may be worth considering if 3/4 or larger sizes are called for. Maybe the islanded section would best be connected through some other route, away from this root zone.
    – Greg Hill
    Commented Aug 12, 2019 at 16:56

Copper kills trees. A copper pipe will not break due to roots as the tree will avoid it

  • The concept is valid. But The answer lacks details on how to use this suggestion.
    – user113627
    Commented Jun 15, 2021 at 18:19
  • Please add more details or a reference Commented Jun 9, 2023 at 9:19

Rock salt. We use it around septic tanks and sprinkler valves. When roots reach the salt they turn back around! However sometimes even rock salt isn’t enough. I just spent 6 hours with an axe, sawsall, and shop vac to remove a ton of roots that grew around my 2” valves and crack the main housing. They roots actually grew into the valve, then expanded inside and cracked it.

  • Thanks ill just go back in time 4 years to get rock salt. ;p Commented Jun 10, 2023 at 1:26

I think pvc pipe is a little flexible, so it may not be as bad. However I have never used pvc for this purpose. It can crack from pressure from above, like walking or jumping. In fact everyone I know uses alkathene pipe.

However if you want to use pvc, I think that if you surround the pipe with gravel or pebbles it will stop the roots.

  • I used a DURA 3/4 in. x 18 in. PVC Slip Flexible Pipe to solve my problem and moved the rest of the pipe, away from the tree to move along the path of the brick. While doing so, we installed 3 more sprinklers to hit more of the area. Commented Jun 10, 2023 at 1:30

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