A failed sewer line understandably strikes fear in the hearts of homeowners. For one, the high cost of sewer line replacement can make a major dent in most homeowners’ bank accounts. For another, a completely failed sewer line means that all wastewater operations in the house must cease: toilets, sinks, showers, and bathtubs.
When a contractor produces an estimate on costs to fix your sewer line, the estimate includes both the cost of digging the trench with earth-moving equipment and the cost of the actual pipe replacement.
If you are up to the task of hand-digging the trench required to access the old sewer line, you can cut costs dramatically. If you go the next step and replace the line by yourself, the cost of replacing the sewer line comes to cents on the dollar as compared to full-service replacement by a contractor.
How Deep Is a Sewer Line?
Sewer lines on private property can be as shallow as 18–30 inches deep or as much as 5–6 feet deep. In areas with cold climates, the pipe will be buried deeper to prevent freezing in the winter.
Pipe depth is not always a matter of climate. Even in warm climates, the pipe can sometimes be buried very deep—it may depend on where your community’s sewer mains are located.
Sewer lines on private property are not the same as public sewer mains, which are a minimum of 12 feet deep.
Trench shields prevent the walls of the trench from collapse, and OSHA (Occupational Safety and Health Administration) regulations require the use of trench shields for trenches 5 feet deep or deeper. As a homeowner, you are not bound by OSHA regulations, but it is wise to follow OSHA guidelines for your own safety.
Digging a trench down to your sewer line is mostly just a matter of hard work. It is not technically difficult, but it can be extremely demanding physically. No materials are required, and the tools are simple ones that many homeowners already have on hand or can rent.
One adult in reasonably good shape may expect to dig a sewer trench 4 feet deep by 8 feet long by 3 feet wide in one weekend of long workdays. This estimate is based on the assumption that you have loose soil with a moderate number of roots to cut through. Clay or densely packed soil, as well as the presence of many large roots, can increase digging time significantly.
Temperature and Climate
Cold climates can present additional complications. In these areas, the sewer pipe can be quite deep because the frost line (the depth to which the ground freezes in winter) may be 4 feet or more below the surface.
Also, if your sewer line fails in winter, you are faced with the difficult task of breaking through the frozen ground in freezing temperatures. This may be impossible to do by hand, and you may need to call in earth-moving equipment.
Digging and then working in a deep trench can be dangerous. According to the CDC, an average of about 20 workers die annually when the earthen walls of trenches collapse on them while they are working within the trenches. An open trench also poses a distinct hazard to children and pets. Make sure to take all necessary precautions to prevent an accident.
Source: The Spruce