How to Fix a Residential Sewer Line Clog

by Chris Deziel Google
    Sewer blockages are often caused by tree roots.

    Sewer blockages are often caused by tree roots.

    It's vexing when a toilet, bathtub or sink drain clogs, but you've got a real problem when it happens to a sewer line. An obstruction in the sewer affects all the plumbing fixtures in the house, and if it gets bad enough, you may find sewage backing out of some of your drains. Clearing a blocked sewer usually isn't a job you can do yourself. It takes professional expertise and equipment.

    Why Sewers Clog

    Sewer lines are typically 6 inches or more in diameter, and it takes more than a buildup of paper or loose debris to clog them. Most sewer clogs are the result of the incursion of tree roots into the pipes. The roots are attracted to the warmth and moisture of the sewer lines and send feelers through tiny cracks or loose joints. Once inside, the roots engorge themselves on the readily available nutrients. Before long, debris collects on the roots and blocks the water flow. The obstruction builds more quickly as the water flow slows and it becomes easier for debris to settle.

    Diagnosing the Problem

    If you have a clogged sewer, your drains will all run slowly no matter how hard you try to clear them. Moreover, you may hear gurgling sounds coming from the waste pipes when you flush a toilet. After eliminating the other possible causes for the sluggish draining — including blocked vents — it is possible to get a visual inspection of the inside of the sewer pipes with the help if a miniature camera. Such inspections, offered by sewer cleaning professionals, may reveal not only roots and other blockages, but also cracks and breakages in the pipes caused by the roots.

    Mechanical Cleaning Methods

    Sewer cleaning professionals have a variety of tools at their disposal for clearing sewer blockages. One such tool is an auger, which is similar to a sink or toilet auger but is much longer and power-assisted. It is frequently mounted on the back of a truck, and may be fed into the sewer in sections. Another useful tool is a high-pressure water jet capable of developing a pressure of 4,000 psi to literally blow the roots and obstructions down the line. Both of these cleaning devices can injure you or damage the pipes if misused.

    Chemical Cleaning Methods

    You can't safely clear sewers with a caustic chemical as you can smaller drain lines, and the only reason for introducing chemicals is to control tree roots. Many plumbers recommend flushing copper sulphate down the toilet to kill roots, but it flushes away quickly, so you must do it often. Moreover, it isn't allowed in every municipality, nor is it safe for septic systems. An alternative is to flush a root-killing foam that contains metam-sodium and dichlobenil. The foam clings to the pipes and the chemicals kill roots within a few hours, although it may take weeks or months for them to wash away.

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