Neighbor's tree trunk breaking through fence

[hlevin]

I am in California.

We bought our house about 9 years ago and the tree in question was already planted by the neighbor on his own property. While the tree was close to the fence it did not appear to be touching the fence at that time. Couple years later we installed a sprinkler system running the pvc pipes along the fence on our side. All seemed well until this spring, as I was adding to the irrigation system, I noticed that the trunk of the tree in question has expanded significantly and began to push on the fence at the base. Right away I contacted the neighbor (by phone) informing him of the problem and asking to remove the tree before the fence actually breaks, unfortunately he chose to ignore my request.

This past weekend I was doing some fall preparations (moving planter boxes, etc) and I noticed that the fence is starting to crack. My further investigation revealed that the sprinkler pipes have been pushed out of the ground and against the adjacent concrete slab covering the ground, furthermore, that concrete slab ~2x4 feet was elevated on one side by about an inch.

I called the neighbor and left him another message restating my original concern as well as describing the new damage. It's been 2 days and I have not heard back, I most likely won't get a response.

I am familiar with section 833 of CA Civil Code, however the tree trunk was not encroaching on my property when we bought the house. The damage also did not become apparent until this spring. I am guessing that my neighbor is going to try to wait it out for the statute of limitations to run out but I don't want to let that happen nor have any alternate way of rerouting the pvc pipes.

Is my neighbor liable? Am I also responsible for the cost of tree removal as well as fence repairs? The fence is in a very good shape in other sections, it's not even close to the end of its useful life. How should I proceed? Should I send a certified letter with a warning or just simply file a claim in small claims court?

BTW, I am not concerned with preserving a peaceful relationship with that neighbor as he does not live on this property and holds it as a rental.

Thanks,
Henry