Replacing a sewer line is expensive, so you don't want to do it until you absolutely have to. There are some signs that can tell you when it is time to replace your sewer line.
Signs of failure
If you have gurgling noises in your toilet, have water that drains very slowly, have a sewer smell in or around your house or see patches of your lawn that seem to be moving or sinking, it could be a sign that your sewer line is failing. If you see those signs, you should have the line inspected.
Agev
If you have an older home, especially one built in the 1970s or earlier, you probably will face this prospect sooner or later. Most sewer lines in older homes were built with clay pipe that cracks and breaks.
Who pays
More than likely, you will have to shoulder the cost of the sewer line replacement, which can cost several thousand dollars. Homeowners insurance usually doesn't cover it, and your local government usually will not pay for any infrastructure that is on your property.