PVC sewer pipe commonly lasts 50 to 100 years, and the PVC Pipe Association puts its service life beyond 100 years. It outlasts cast iron and clay because it does not rust or corrode. Actual life depends on installation, bedding, and soil movement rather than the plastic breaking down.
PVC does not rust, scale, or corrode, so it has no decay clock the way metal pipe does. A longevity review by the PVC Pipe Association, drawing on more than 60 years of field experience, pipe dig ups, and laboratory testing, concluded that PVC water and sewer pipe has a service life in excess of 100 years. The plastic is also immune to the sewer gases and household chemicals that eat away at older materials.
That is well beyond the common sewer materials it replaced. Cast iron pipe typically lasts 50 to 100 years and fails as rust thins the pipe wall from the inside, which you can read about in our note on how long cast iron pipe lasts. Clay pipe commonly lasts 50 to 60 years and usually fails at the joints, not along the barrel. PVC avoids both of those failure paths, which is why it carries the longest expected life of the three.
The honest limit is that PVC does not fail on a schedule the way its material rating suggests. Poor installation, shallow or uneven bedding, expansive clay soil that shifts with the seasons, or heavy crushing loads overhead can crack, flatten, or pull a joint apart in far less than 100 years, regardless of the plastic itself. When that happens on an otherwise sound line, a damaged section can often be renewed with sewer pipe lining instead of a full dig and replacement.