The best option for fixing a slab leak will depend on the nature of the problem. In some cases a new pipe can be installed without having to tear up the slab to get access to the faulty pipe. This option is called a reroute and involves adding a new pipe in the ceiling and walls to replace the one below the slab. This option can be rather intensive and will require adding new drywall when everything is done. In other cases, the leaking pipe may need to be accessed directly which requires digging through the slab itself. This can be an involved project which can take a while a make quite a mess.
Rather than replacing the leaking pipe, it’s also possible to repair the leak with epoxy which, if done correctly, should also prevent future leaks. This option can be cheaper, easier, and faster than the ones mentioned above.
Older pipes may be made out of a material like polybutylene that is more likely to develop holes over time. If your house was built after the mid 90s chances are you don’t have that kind of pipe, as it is more common now for PVC and copper to be used. PVC is pretty common; you’ve probably see it at the hardware store. They are the long white pipes. The problem with PVC, however, is that it can grow bacteria. Copper is harder to install and may become corroded.
So depending on the type of pipe involved your repair options may differ.
If you keep having issues, a solution may be to replace your older pipes with newer, more resistant materials.