Sewer line problems: what they look like and what fixes them

Every drain in the house leaves through one pipe, the sewer lateral that runs from your foundation to the city main, usually under the street. When that pipe has trouble, every fixture shares the symptoms.

The signs it's the line, not a drain

• Multiple fixtures slow or backing up at once. One slow sink is a clog. The tub, the toilet, and the basement drain complaining together is the main line.
• Gurgling. A toilet that bubbles when the washer drains, or a tub that gurgles when a toilet flushes, is air being pushed past a partial blockage.
• Recurring backups. A line that was cleared and backs up again within months is telling you the blockage has a cause, not just a location.
• A wet or sunken spot in the yard. Sewage reaching the surface means the pipe is broken, not just blocked.
• Sewage smell near drains or outside along the line's path.

The usual causes here

The metro's older laterals are clay or cast iron, and the trees that make Portland green are hard on them. Roots find the joints in clay pipe, grow inside, and catch everything that passes until the line closes. Older pipe also cracks, settles into a belly where waste collects, or corrodes through. On a pre-war home the lateral is very often original, which means it's past its design life.

See it before you fix it

A sewer camera scope runs a camera down the line and shows exactly what's wrong and where: roots at a joint, a belly, a break, or a collapsed section. It's worth doing before agreeing to any repair, and it's standard practice on older-home purchases in Portland for good reason. A scope turns a guess into a map.

The repair options

• Spot repair. One bad section, the rest healthy: dig up that section and replace it.
• Trenchless lining. A resin liner cures inside the old pipe and seals it from within. Works when the pipe still holds its shape; trenchless sewer work avoids tearing up the yard, the driveway, and the landscaping.
• Pipe bursting. A new pipe pulled through the old one's path, breaking it outward. Also trenchless, and it handles lines too far gone for lining.
• Open trench. Sometimes the only option, when the line has collapsed or the slope is wrong.

A line that backs up once gets cleared. One that backs up again gets scoped. Describing what you're seeing on the contact form is enough to get the right crew out.