As professional home inspectors, we often encounter sewer line issues due to lack of maintenance across homeowners. This underground pipeline, connecting your home's plumbing to the main sewer system or an onsite septic system, is crucial for the smooth functioning of your household’s drainage system.

Many homeowners mistakenly believe the public sewer utility is responsible for the underground sewer line right up to the street connection. In reality, homeowners are responsible for the entire sewer line from their home to where it connects with the public sewer. This includes both the upper lateral (from the home to the property line) and the lower lateral (from the property line to the public sewer connection).

We always advise clients, especially those buying homes older than 10 years, to inspect their underground sewer line before closing. Historically, sewer lines were made of cast iron or clay, often used into the 1970s. While you may see Polyvinyl Chloride (PVC) pipes inside your home, the underground lines might consist of older materials. Today, most modern homes use PVC sewer lines.

WIN Home Inspection utilizes a sewer camera equipped with a 120-foot cable and an LED light for our Sewer Scope Inspection. This camera is inserted into the sewer line, and we record the interior condition of the pipe as we push the device through. Common issues include breakages, blockages from tree roots and low spots granting water accumulation. Entry points for the camera include exterior or interior cleanouts, and sometimes, though rarely, the roof mounted, plumbing stack vent.

For homes with septic systems, we recommend inspecting the lateral drainpipe between the home and the septic tank. This part is often omitted in standard septic inspections, which usually focus on the tank and drain field.

Why do I Need a Sewer Line Inspection?


Tree root infiltration threatens older homes, as they already have an increased risk of sewer line damage or blockages. Slow draining across multiple fixtures simultaneously is a clear indicator of sewer line blockages. Additionally, an unusually green patch of grass in your yard indicates leakage. Most home buyers don't think to inspect the sewer line during a home inspection, not realizing repair costs can be steep, often starting at $2,000 and escalating quickly. Regardless of tree presence above ground, underground roots from previously removed trees can still pose a threat to your sewer lines. These roots, still searching for water, can exert considerable force to infiltrate sewer pipes, especially at seams or breaks.

A blocked sewer pipe can cause backups into your home, potentially damaging appliances and growing mold. The inspection of underground plumbing, including the sewer drain line, falls beyond the scope of standard home inspections. However, WIN Home Inspection offers a comprehensive Sewer Scope Inspection as an additional service to our Full Home Inspection for those in the housing market and to our Healthy Home Check for homeowners. Contact your local WIN home inspector today for locational service and pricing information.

The potential costs and headaches of sewer line issues are hefty, so it is wise to properly educate yourself beforehand. We recommend sewer line checks to all homeowners to establish peace of mind and avoid unpleasant surprises down the line.

Author Bio:

Josh Rogers

As a former professional home inspector and Training Specialist at WIN Home Inspection, Josh has years of experience in both performing and teaching home inspections, infrared scans, radon testing, mold testing, and more.