Tree roots can grow into PVC pipe.
If trees are planted near PVC pipe or you bury PVC pipe near trees the Tree roots can eventually grow into the PVC pipe and crack it and split it open.
While tree roots can penetrate PVC pipe, it's more durable and does not break down as easily as other materials.
Note where the trees are on your property, including the species they are.
The flow of warm water inside the sanitary sewer service pipe causes water vapor to escape to the cold soil surrounding the pipe.
Tree roots are attracted to the water vapor leaving the pipe and they follow the vapor trail to the source of the moisture, which are usually cracks or loose joints in the sewer pipe.
Copper sulfate is a natural herbicide and will kill off the small tree roots invading your sewer pipes.
Flushing half a cup of the crystals down the toilet should do the trick.
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.
Placing small rocks under, and on the sides, and finally above the pipe.
If not disturbed once inside the pipes, tree roots will completely fill the pipe, expanding and exerting considerable pressure at the crack or joint where they entered the pipe as the roots continue to grow.
The force exerted by the root growth will break the pipe and may result in total collapse of the pipe.