Sewer insurance company suggestion for rental sfr

[Ron Singh]

trying to see if its worth adding a sewer insurance (around 40+yr old home in CA) there is a huge tree in front yard and i have a feeling now or later it may cause issues in sewer line, which is under/near tree.

Anyone had good experience and suggest the process, and also how to make sure, insurance company won't create issues in claim in case needed in future (hearing horror stories on it)

how to go about it ? and what to ask/make sure is covered.