SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

If you are only putting in a single pipe, then either jmduke7 or lush96 are offering good advice. Additionally, since it sounds like your dealing with a mature tree, it might not be as much of an issue.

Now in my case, I was trenching near a tree where in a few years the trench WILL be within the drip line of the tree. I was placing multiple pipes in a trench, and my fear was tree roots growing between pipes and swelling in size of the years and break the pipe. So to help avoid roots growing BETWEEN pipes, I lined the side of the trench with vinyl siding.

And the other thing I would think would help... the deeper the better (the roots closer to the drip line will be closer to the surface, so the farther UNDER them you are, the less likely they will bother your pipes).

just lay the pipes in. the pvc will do minimal help. roots will crush and crack pvc just the same as poly. your best bet is to start chopping the roots. it will be many years till the roots actually restrict the water flow. installing pvc may give you and extra year or two. if the trees are fully grown, the roots will grow very slow. you wont have probs for 10- 20 years.

I would recommend laying some sleeves in the trench (larger diameter pipe (such as 2" sch 40 pvc) and then put smaller diameter pipe inside). This will enable the larger sleeving to take the blunt of the force of all the roots, while protecting the smaller pipe inside.

Any hints when burying sprinkler lines near large trees under the drip lines? Due to the layout of my yard, I will have no choice but to run the poly lines under the drip lines of existing large maple & oak trees. Do I need to take any precautions to protect the sprinkler lines from future root damage, such as vinyl siding in the trenches? I'm not too concerned with unavoidable damage to the tree roots while trenching.