A friend has a leak in his home drain system. By use of hydrostatic and isolation tests it has been determined that there are two leaking Y joints in the pvc drain under the slab foundation. There appear to be two ways to fix this. One is the traditional for the area of digging a trench under the slab and repairing the pvc joints. This is done with permits, city inspection, and an engineer supervised filling of the trench. The other method is to run a liner down the pipe. He wants to know which is the best fix? Can the liner fix a leaking Y or only a leaking straight run? How well does the liner work on the small diameter pipes in household drain? I have been told that liner repairs on small pipes do not last like they do for city sewer pipes - any truth to this? Any other information or questions I should suggest to him? Thanks for any help you can give.