Posted:
As tempting as it may be to tell this guy to kick rocks because he owes the association a ton of money, we have to start with separating the issues because the trees may be part of the common area as well as the utility line from the point it leaves the home, meaning the association may be on the hook for that portion of the repairs. I live in a townhouse community and that's how our master insurance policy works. Not so fun fact - in many individual homeowner insurance policies, sewer and water damage isn't automatically covered, so you have to get additional coverage for that.
Get your own plumber to assess the damage and check your documents, along with the association's master insurance policy. I also live in a townhouse community and if your master policy is similar to ours, coverage of utility lines (like sewers) from the point they enter the unit is homeowner responsibility. In fact, everything from the drywall in is the homeowner's responsibility, so not only might the homeowner be responsible for that, but he'll also have to deal with the damage to the toilet, the carpeting, etc. Hope he has the right coverage, but then again insurance companies duking it out with each other is what they do.
All of that said, make it clear to this homeowner that determining the HOA's liability in this DOES NOT trump the fact that he's behind in assessments, so the lawsuits and lien will continue until he makes them current. If this escalates to a foreclosure by the HOA, so be it (be sure to discuss the pros and cons with your attorney before going that route)
We had several tree-root-in-the-sewer-line incidents, and after paying between $4K and $7K for repairs, we ended up hiring an arborist to go through the neighborhood and identify which trees were likely to cause problems in the future. The developer had planted a bunch of trees around the community, but most of them were too close to the homes. Our community was also built in the 70s when clay pipe was a thing and tree roots are very good at going through them. People forget that tree roots are twice as long as the tree is tall and they're ALWAYS looking for more moisture, so you might consider doing the same to see if you can identify and head off problems. Meanwhile, encourage all homeowners to make sure their sewer cleanouts are accessible, consider getting their own sewer/water damage coverage and dropping a bottle of root killer like Rid-X in the downstairs toilet or cleanout once a month. the root killer might set you back $70 or so bucks a year, but that beats the hell of the the expense and stench of repairs from tree root disruption.
If it is not right do not do it; if it is not true do not say it. Marcus Aurelius