A: 50 to 60 years. If your home is from the 1970s or earlier, you are on borrowed time.
Once a joint fails, it creates an entry point for tree roots. Roots are naturally drawn to the moisture and nutrients inside sewer lines. As they grow, they act like a wedge, expanding small cracks into major structural breaks. This leads to frequent backups, slow drains, and eventually, a total collapse of the line. Traditional Excavation vs. Trenchless Repair clay sewer pipe repair