How Tree Roots Get Into Your Sewer Drain
Trees are brilliant at finding water: their roots can travel a hundred feet to get to the nourishment they need. They prefer loose soil to heavily packed soil, since it makes tunneling easier. The tree doesn't have to work as hard to get to water when its roots move through fluffy soil—soil that's been moved around or even dug up. So it's a natural bet that tree roots will sometimes invade sewer lines, causing distress to homeowners everywhere.
Tree roots may cause your sewer line to back up, sending raw sewage into the house. If they grow big enough, they may rupture sewer lines, meaning a lot of expensive and messy clean-up work. Old houses are notorious for problems with tree roots in sewer lines because the old sewage pipes were made of clay and joined together with mortar. Aside from the fact that we've all seen what moisture does to compounds made of cement, mortar crumbles over time. When a thirsty tree sends out its tiny roots in search of liquid and organic nutrients, the cracks in the mortar between the old cement sewage pipes make a perfect entry point for small rootlets. Even this wouldn't be a big problem, except for the fact that as the roots find what they seek in the way of moisture and nutrition, they start to grow and grow. Eventually, there are big roots in the sewer.
When it comes to having tree roots in your sewer line, you don't have too many effective choices. There are some products that you can put down the toilet, which claim to kill tree roots in sewage lines, but they often don't take care of the problem adequately, and you can wind up with worse problems than before. The problem with these products is that sewer lines are rarely actually full: the sewage tends to rest in the bottom part of the line. For tree roots to be affected by chemicals in the sewer line, they would have to be immersed in them: otherwise, the ends of their rootlets may get burned (if they hang down far enough), but the main part of the root may stay above the remedy. The tree continues to prosper.
THE COPPER SULFATE SOLUTION
The best way to stop the roots that have joined the sewer is to convince them to go elsewhere by using copper sulfate in the soil around the sewer line. Trees hate copper sulfate, but homeowners love the stuff, because it may be all that stands between them and paying for a brand new sewer system.
ASSESSING THE PROBLEM
The hardest part of using copper sulfate is in figuring out where your sewer lines actually lie. Not only do you need an accurate idea of where each line is, you also need to know the depth of the line at the point or points most likely invaded by tree roots. If your house is on a city sewer line, you can go to the city office and find exactly where your sewer tap is, and then trace the line (usually coming off the main at a 90 degree angle) back to your house.
An even better option is to call Dr. Pipes at 1-877-377-4737, and hire a local plumbing company that performs camera line inspections. They send the camera into the line and map the exact line for you, including the precise location of tree roots in the line. Electronics have also made it possible for sewer companies to tell you the depth of the line at any point along the way.
DRILLING YOUR HOLES
Once you have the information on location and depth of the sewer line where the roots are, you can use an earth auger to drill a 2.5 inch diameter hole in the ground above where the roots are in the sewer line. First, make sure there are no other utility lines where you plan to drill—call the electric, gas and cable company to make sure you have a free and safe access.
You'll also want one or more lengths of 1.5 inch PVC pipe and a means of cutting it to the right length. You will drill straight down toward the sewer pipe, stopping when you get to a place 24-30 inches above the sewer line. You don't want to go too far down, because the solution you're going to pour into the PVC pipe should go into the soil above the sewer line. Cut the pipe to the length of the hole, and attach a threaded female adapter with a plug onto one end of the pipe.
Once you have the hole drilled, put the pipe into the hole, and if it needs trimming to lie flush with the ground (and below the grass, so you can't run over it with the lawn mower), pull it out again and cut a little off the bottom until it fits just right. If you have a lot of roots in the lines, or a root that extends a long way through or near a line, you will probably want to insert a PVC pipe at each trouble point and every 6 feet or so along the line of trouble.
USING THE COPPER SULFATE
Now comes the big fun: take off the plug at the end, and pour copper sulfate into the pipe until it's about half full of the crystals. You can buy copper sulfate at feed stores, nurseries and some old-fashioned hardware stores. When the PVC pipe is half full, pour hot water into the pipe until it tops up and runs over a just a bit. The copper sulfate is dissolved in the hot water, and starts to run into the soil around the ground. Tree roots hate copper sulfate, and will turn away. The ones in the sewer line will die.
ALWAYS KEEP RECORDS
Whenever you do something that's not easily seen, such as putting pipes into the ground around your home, you can save yourself a lot of trouble later on by creating a record of the work you did. Use a camera, GPS or a hand made map to accurately show where you put the PVC pipes in your ground. Who knows, you may need to install sprinklers some day, or you may want to add pipes to counter other root systems: it's important to know where things are laid. Put the map with your other important household maintenance papers, so you never have to hunt for it.
The copper sulfate solution works, but it's not a one shot deal. You need to reapply the copper sulfate every four months, or the copper sulfate will leach out of the soil and the trees will send new roots to the sewer. Make applying copper sulfate solution part of your regular routine—once a season, to keep the roots away.
PATIENCE IS A VIRTUE
While copper sulfate is a great solution for deterring tree roots, but it's not an overnight one. It takes months for trees to get into the sewer, and it takes months to turn them back from it as well. You have to wait for the copper sulfate to take effect on the trees, and that will take some time. But it works, so it's worth the wait. It may be worthwhile to call Dr. Pipes at 1-877-377-4737 to inquire about having a professional take of it for you. You might be surprised how affordable it is.