Recognizable Signs of Sewer Problems

Sewer problems often leave indicators which can be easily identified during a routine property inspection. Some of the most noticeable signs are:

Water Staining

Water stains around the basement floor drains are an obvious sign the sewer line is not draining properly. Because the floor drain is usually the lowest access point to the sewer, it provides some of the first indications of a sewer problem.

Physical Damage

Cracked walls or floors suggest movement of the foundation. Shifting foundations can be caused by excess water in the soil, which could be coming from a broken sewer line. Other obvious indications of damaged sanitary infrastructure are sink holes and sewage odors indoors and outdoors.

Replaced “Clean Out” Plugs

Sewer lines usually have a “clean out” access that is typically found on the main sewer line in the basement, crawl-space, or outside the house. Prior to the 1980’s, a brass “plug” was used in residential construction. If the original plug has been replaced, it’s likely that sewer work, such as auguring or chemical cleaning, has been required at some point.

Notching of the PVC “Clean Out” Access

The most common method of clearing an obstructed sewer line of roots/debris is with an auger, which is normally fed through a cleanout. The rotating cable that turns the blade of the auger will often grind on the pipe, creating a small, visible “groove” or “notch” in the PVC material, just inside the clean out. There may be indications of this in other pipe material, but likely most obvious in PVC plastic pipe.

Service Labels

The presence of service stickers on or near sewer pipes is another sign that the sanitary system has required maintenance at some point. These labels might also indicate that the property is on a “preventative maintenance” program for regular cleaning to prevent future backups.

Outside “Clean Outs”

An outside cleanout that is not original to the home is a possible indication that a spot repair was performed at some point, or that an additional, larger access point was required for regular maintenance, such as mechanical cleaning of the line.


Trees, especially large ones, near the area of the yard where the sewer line runs should always be cause for concern. This is especially true if it is known that the sanitary pipe is made from clay. Older clay pipe often has non-sealed joints every 3 feet or so (though this can vary some), which present an excellent opportunity for roots to get into and damage the pipe.