Several drains backing up or slowing at once, gurgling toilets, sewage smells and backups that keep coming back point to the main sewer line, not one drain. In older homes the usual causes are tree roots, scale in cast iron, or a cracked or sagging line. A camera inspection shows which. At Gold Seal, clearing a main line through an outside cleanout starts from $568.
How do I know if the problem is the main sewer line?
Count the drains. One slow sink is a local clog. When several fixtures act up at once, or the lowest drain in the house backs up, the trouble is usually in the main line that carries everything out to the street.
What are the warning signs of a failing sewer line?
- Several drains slow or backing up at the same time
- A toilet gurgles when a sink, tub or washing machine drains
- Water comes up in a floor drain or the lowest tub or shower
- Backups clear and then come back weeks or months later
- A sewage smell near floor drains, the cleanout or in the yard
- A strip of greener, faster-growing grass along the sewer path
- A soggy or sunken spot in the yard over the line
What causes sewer lines to fail?
| Cause | What happens | Most common in |
|---|---|---|
| Tree roots | Roots find a crack or joint, grow inside and catch everything that comes down the line | Clay and older pipe with many joints |
| Scale and corrosion | Cast iron rusts and scales from the inside until the pipe narrows and cracks | Older cast iron |
| Orangeburg pipe | Tar-soaked fiber pipe deforms under the soil and eventually collapses | Lines laid from about the 1940s to the 1970s |
| A belly | Part of the line settles, so water and waste sit in it instead of draining | Any pipe, once the soil under it settles |
| Grease and wipes | Grease hardens on the pipe wall, and wipes do not break down | Any line |
What does a sewer camera inspection show?
A camera on a cable travels the line and shows roots and the joint they come through, cracks, collapsed sections, bellies, offset joints, scale, and how much of the pipe is still open. It measures how far along the line each problem is, and a locator lets us mark the spot and its depth from the yard, so any digging happens in the right place. You get a copy of the footage.
Sometimes the answer is that nothing needs doing. Knowing the line is sound is a useful result, especially before you buy a house: a standard home inspection does not include the sewer line.
What does it cost to clear and inspect a sewer line?
| Job | Starting price | Members |
|---|---|---|
| Main line cleared through an outside cleanout, up to 100 feet | From $568 | $511 |
| Main line cleared through an inside cleanout, up to 100 feet | From $721 | $649 |
| Main line cleared through a toilet, up to 100 feet | From $823 | $741 |
| Heavy roots in the main line, up to 100 feet, added | From $283 | $255 |
| Camera inspection of the cleaned line | From $304 | $274 |
| Hydro jetting, first hour | From $462 | $415 |
Gold Seal flat-rate book, 2026. Ask about $100 off main line sewer cleaning. Estimates for sewer repair and replacement are free.
Should I keep cleaning the line or fix it?
Cleaning clears the blockage. It does not fix the crack or joint that let the roots in, so roots usually come back within one to two years. If your line needs clearing on a schedule, the camera footage helps you weigh regular cleaning against a permanent repair. LightRay UV lining seals the joints roots get through and starts from $6,426 for up to 50 feet.
What should I do if sewage is backing up right now?
- Stop running water in the house. Every flush adds to what comes back up.
- Keep people and pets away from the water. Sewage is a health hazard.
- Skip chemical drain cleaners. They will not clear a main line, and they make cleanup more dangerous.
- Call us at (509) 535-5946. A person answers 24 hours a day.
Written by the Gold Seal teamLicensed plumbing contractor · WA L&I GOLDSSM799MG · ID DOPL PLB-C-8717 · updated October 28, 2026
