Problems with your sewer line are every homeowner's worst nightmare, and an issue known as back-pitch can be particularly troublesome to deal with.
What Is Back-Pitch In Sewer Lines?
To function effectively, a sewer line must slope slightly downwards as it runs away from your home and towards the main municipal sewer. This gentle slope allows gravity to guide solid and liquid waste along the sewer line, helping to prevent backups and blockages. The angle of your sewer line's slope is referred to as its 'pitch'.
Back-pitch occurs when a section of the sewer line shifts out of position, causing it to lose its downward pitch and become level, or ever slope upwards. Waste materials will flow more slowly through a back-pitched section of a sewer line and may stop flowing entirely. This can cause a serious blockage in the sewer line and may lead to sewage backing up into your home.
Back-pitching can also lead to a phenomenon known as 'bellying', where a section of the sewer line starts to sag lower than the adjacent sections. Sewage can quickly accumulate in a bellying section of a sewer line, causing it to corrode more quickly and lose integrity.
In extreme cases, the bottom of a bellying sewer line can corrode away entirely, causing large amounts of sewage to leak into the surrounding soil.
How Can Landscaping Work Cause Back-Pitch In Sewer Lines?
The most common cause of back-pitch in sewer lines is soil settling. If the soil beneath a section of a sewer line sinks and settles due to ground disturbance, the sewer line above it will also sink, causing bellying. Conversely, if soil is added to the space beneath a sewer line during excavation work or topsoil replacement, the additional soil can raise the slope of the sewer line.
If your home's sewer line runs under a garden, yard, or flower bed that has recently been landscaped, any alterations made to the soil around your sewer line can cause settling, which in turn can lead to sewer line back-pitching. Professional landscaping services will usually take care to avoid disturbing your sewer line, but any accidental disturbance of the soil beneath a sewer line can cause back-pitching.
How Can You Tell If Your Sewer Line Is Back-Pitched?
If your home's sewer line is suffering from back-pitch, you may notice slower drainage in your home's sinks and bathtubs. More serious back-pitching problems can cause sewage to back up and start flowing into your home. This can cause serious damage to your home's fixtures and fittings and pose a serious health risk if you are exposed to untreated sewage.
If your sewer line is leaking as a result of bellying issues, you may notice the ground around the damaged section of the sewer line is flooded and waterlogged, with a distinctly unpleasant smell. Any grass or plants growing over the damaged section may grow larger and more rapidly.
If you notice any symptoms of sewer line back-pitching, you should call in a sewer line repair service as soon as possible to have your sewer line inspected and repaired.