The year your house was built tells you, with decent accuracy, what your sewer line is made of. That matters because each material fails in its own way and each one points to a different repair.
Cast iron (roughly 1900 to 1975)
Cast iron was the standard drain material under slabs and inside the house for most of the twentieth century. It is strong, quiet, and rusts from the inside out. Expected life is 50 to 75 years, which means nearly every original cast iron line in the country is at or past the end.
How it fails. Scale builds up on the inside wall and narrows the pipe. Eventually the bottom of the pipe rusts through, a condition called channeling, and waste runs on the soil under the slab while the top half of the pipe looks fine. In acidic or wet soils, especially in Florida and along the Gulf Coast, this happens faster.
Best repair. If the wall is still mostly intact, descaling and lining works well and avoids breaking the slab. Once the pipe is channeled along a long run, lining has nothing to bond to, and replacement is the honest answer. Under-slab cast iron replacement is the most expensive version of this job because the floor comes up.
Clay tile (1900 to about 1980)
Vitrified clay pipe was used for the line from the house to the street, in short sections with joints every two to three feet. Clay itself lasts a century. The joints do not.
How it fails. Roots find the joints. Ground movement offsets them. Once a joint opens, soil washes in and a belly forms behind it. A clay line that is intact but rooty is one of the best candidates for trenchless lining, because the liner becomes a continuous jointless pipe inside the old clay.
Best repair. Root cutting plus lining for intact runs; spot repair for a single badly offset joint; pipe bursting when several sections have crushed.
Orangeburg (1945 to 1972)
Orangeburg is bituminized fiber pipe, essentially layers of wood pulp pressed with tar. It was cheap and easy to install during the post-war building boom, and it was never meant to last more than about 30 years. Any Orangeburg line still in service is decades past its design life.
How it fails. It absorbs water and deforms. The pipe goes oval, then flattens, and the top sags into the flow. Roots push straight through the wall. On camera it looks like a pipe with no defined shape, sometimes described as “blistering” or “delaminating.”
Best repair. Replacement. Lining Orangeburg is possible in narrow cases, but the deformed shape often will not accept a liner and the wall offers nothing to bond to. Pipe bursting is the common fix when the path is clear; dig-and-replace when it is not. If a seller’s disclosure or a neighbor’s replacement mentions Orangeburg, budget for the full job.
Concrete (1940s to 1970s, mostly in the Northwest and Midwest)
Concrete side sewers behave like clay: long life for the pipe body, weak joints, and heavy root intrusion. Ground water attacks the joints and the interior over time. Repairs follow the clay playbook: lining for intact runs, spot repairs for single failures.
PVC and ABS (1975 to today)
Plastic lines are jointed with solvent weld, which roots cannot enter. Failures are rare and usually come from construction damage, a crushed section under a driveway, or a bad belly from poor bedding. If your home is post-1980 and the scope found a problem, it is almost always a localized spot repair, not a replacement.
How to tell what you have
Check the build year first. Then look at the cleanout in the yard or the pipe exiting the foundation: black and heavy is cast iron, reddish-brown segments are clay, white or black plastic is PVC or ABS. Orangeburg looks like black fiber and is often flaky at a cleanout. When in doubt, the camera inspection report names the material within the first few feet.
Send us the report and we will confirm the material, explain the failure pattern you are looking at, and tell you which repair method a fair quote should be based on.