Roots in PVC downspout drains
I have two 4" PVC pipes running under a flower bed that serve as the drains for two downspouts. Quite a few years ago, when I replaced a retaining wall at one end of the bed, I left an opening at the bottom of the wall for them to drain. But I neglected to check it for, um, years. [Yes, I know, that was stupid. I know better, especially now, but I can only fix that going forward.] Recently I noticed that, when it rained, water was overflowing at the junction of the downspout to the PVC drain. I opened it up and found the PVC filled with grit and fine roots. I looked at the neglected exit and found roots growing up into both pipes. There are several per pipe, 3 or 4 between 1/4" and 5/8" in size and quickly turn into a mass. I've cut the roots off, but that didn't make them disappear.
Obviously, I need clear pipes for proper drainage Replacing the pipes is undesirable, I'd like to clean these out. The two pipes are about 20 feet and 15 feet long respectively.
I've tried spraying water into the pipe using a garden home from above but I quickly reach the point where no soil comes out. I've tried that from below and it took a while, but the same has happened there, too. I've tried to grab the vines with lock grip pliers and pull the vines out, but the vine eventually breaks in the pliers grip. I have a 3" x 24" auger that I tried to drill up into the pipe (pipes have straight exit, and a bend right below the surface at the entrance), to try to lodge it in the roots and pull them out, but so far no luck (drill is uncooperative, need to remove bricks/dig a bigger hole for better access, etc.) I do not have a sewer line camera.
Other ideas I've had:
- Rent a rotary drain cleaner with a cutting head from a home improvement store ($$)
- Purchase a pressure washer and use a sewer jetter head, in hopes it'll destroy enough of the small roots that the large ones can be pulled out. ($$)
- Hire a plumber to do one of the above ($$$)
The pressure washer sounds like the safest alternative, and about the same price as the rotary drain cleaner (at about $100/day), but I'm not sure it'll get the job done. Thoughts?