A properly installed CIPP pipe liner is designed to last about 50 years. That number is a design life from lab testing, not an observed age. The field evidence comes from U.S. EPA studies, which tested sewer liners in service up to 34 years and found little deterioration. Install quality and the old pipe decide whether yours gets there.
The 50-year figure comes from how a liner is engineered. Labs load liner samples for up to 10,000 hours, then extrapolate the results to 50 years, and that long-term stiffness sets the liner thickness in the ASTM F1216 design method. You can see where the resin and liner fit in how CIPP pipe lining works. The field record is shorter: EPA tested 18 liners from nine cities, aged 5 to 34 years, and concluded they should meet and likely exceed that 50-year design life.
What shortens a liner’s life is usually the install, not the material. A pipe not cleaned to the bare wall, resin that did not fully cure, or a badly reopened side connection can fail years early. In EPA’s first study, the defects found were mostly at reconnected laterals. One honest limitation: those studies tested city sewer mains, not house lines. A liner also follows the old pipe’s shape, so it cannot fix a collapsed or badly sagged pipe. A sewer camera inspection shows which one you have.
The lined section has no joints, so roots cannot get in. Connections and any unlined sections can still take roots, which is why the camera checks the whole line. For upkeep, see whether a lined sewer pipe can be snaked or hydro jetted.