Help - sewer line in sfh I just bought needs to be replaced

[Lewis Kerwin]

Hi all, 

Context: I'm just starting real estate investing this year and just bought a 1955 SFH in a B/C neighborhood in Chicago. I had a sewer inspection done before closing that showed tree roots and quoted me around 3k to replace the downspout and rod appropriately. The seller disclosed a rodding the year before that had "resolved" the tree root issue. I had the price reduced by 3k to cover this risk and closed.

Problem: Now I’m hearing from the property manager (same manager the seller had) that the pipe is so full of roots it will require replacement with tons of concrete to be dug up costing me around $15,000. (apparently they rodded it 4 times in the past year and couldn’t even get through to the sewer main. And the pipe is 6ft down and runs for 40 ft under cement the whole way; backyard is cement). 

Question: 

1) How do I learn to avoid this in the future? I’d thought that a sewer inspection and accompanying quote would protect me

2) If I do need to replace the pipe and tear up a bunch of cement, how do I make the most of this? e.g. could putting in a lawn where cement was facilitate future repairs and add value? Are there other kinds of future maintenance that would require digging which I should just do now? Would removing the tree (would require neighbor cooperation) likely save the pipe? Would the city chip in on any repair if the roots involved the a common sewer pipe? Any other ideas would be appreciated.

Thanks!