Would corrosion stop a snake from going through it?

After years of use, the zinc/galvanized coating diminishes, and corrosion begins.

There was corrosion and rust on accessible waste lines.

But if they’re slamming heavy pots down, scrubbing with corrosive cleaners, or overheating it to the point of warping, that’s tenant damage—plain and simple.The lease is the first line of defense.

YES, you can transition from new copper to old galvanized, but just be sure the plumber uses the right fittings to prevent corrosion.  

If it is roots, joint corrosion, etc we get it chained which has some risk but clears the drain of anything except pipe breakage that would cause a clog.Good luck

Quote from @Margaret Blythe: Quote from @Michael Borger: In coastal areas like Hawaii, where I invest (in addition to Alaska), you have to be mindful of environmental hazards -- hurricane susceptibility, erosion, salt corrosion, etc.

Internal corrosion in the lines can and will affect the pressure and draining capabilities of the plumbing system at some point in the future.

In Mass, that means that all components are double-wall, non-corrosive (fiberglass). 

For example, they might say something like "There is significant corrosion and to repair I might end up damaging other things.