All I know you need to put the phone by the door I don't know the rest
EDIT: There are systems that can install an epoxy liner in an existing sewer lateral. One of many is linked below. They will come into your house with a camera system and run it down the main sewer and find out where the break(s) occur. From there they will install an inflatable pipe within the system that will extrude the new epoxy liner. It may take a few hours, and it will cost about 40% of what a new pipe would cost, but there is little or no digging, and certainly nothing under your house. Ask around in your ara or search No Dig Sewer Repair or similar words. END EDIT. Clay sewer pipe of that vintage used mostly a mortar mix for the sealant - and some very few used rubber gaskets in addition to the mortar. Between settling and normal aging, the joints tend to move a little. And then between heating and cooling, hot water from a bath followed by cold water from a toilet flush, even more stress is put on the joints. Do this for 30 - 40 years and the joints get loose. An air-blaster system will blow the mortar right out of the joints, possibly split the pipes themselves and possibly even move the pipes themselves. It is absolutely the worst possible thing to do with a vitreous-pipe system. Keep in mind that the pipe itself tends to be pretty impervious to wear and tear - it is usually joint failure, movement and roots (causing joint failure and movement) that causes problems. Good luck with it. When/if you have to replace the pipes, consider Schedule 80 PVC if permitted by code. It is much stronger than Schedule 40, and should last at least 100 years, probably much more, if installed correctly. Use 304-stainless no-hub mechanical fittings rated for underground use, *NOT* solvent fittings. Or go straight to ductile iron and similar fittings.
