Dudes, she has a dog. She could just take him for a walk alongside the fence and he’ll pee all over it. Assuming the dog is a male, that is. Otherwise, yeah. Have the grandson do it. 
Too late, Johnny L.A.: already done.
Yes…I live in Arizona and having the walls solves a lot of problems that you hear about in other places when it comes to neighbors.
fnord
DAMMIT!
Yep. We had wormwood fences when we moved to the Antelope Valley. We and the neighbours quickly put up six foot high cinder block walls. (Actually, they were higher than code – but much, much stronger.) Privacy, better protection from the omnipresent wind, and no tumbleweeds. I mentioned to the SO we should build one between us and the trailer neighbour, but she said 'We’re not in the desert, dear! :rolleyes: ’ I actually did mention it to the neighbour the one (out of two) times she talked to me, and she said it wouldn’t look ‘woodsy’. Maybe that’s why she wants to put up the fence herself. 
Leave your fence where it is… plant a line of bushes along your fence in that 2’ area… have them professionally trimmed to look like this: Trimmed bush
Seriously though, good luck. This guy sounds like a nutcase. 
Thanks all, I’ve learned a lot here!
OK, update: Asshole Neighbor’s wife called me this afternoon and apologized for him. (I get the feeling she does this a lot.) I said, “he does realise that the two feet on the other side of my fence is my property, right?”
“Yes, sorry he was having a bad day.”
Translated, I think: “He had too much to drink yesterday.”
Anyway, I will call the township on Monday as a starting point to getting a solid determination of where the property line is - I guess I assumed that a: since the neighbors (who have lived there for over 20 years) put up a fence they would have naturally put it along their property line, and b: the metal post at the back of our properties is actually the physical marker, or so I assumed. Also, c: I measured the side lot four years ago and determined, IIRC, that the width measurement matched up to the lot description, when planning the fence.
But to be sure and legal, I guess I need to determine this exactly.
I could pee along the property line I suppose. But it would be unseemly. (I am female.)
I was actually joking about something rather like this today. Using two pumpkins and some stuffed jeans to make a butt facing their house.
THis is my first reaction. When my father died my mother allowed a neighbor to pasture his cows on her 8 acres off beyond the creek. That was 18 years ago. Last year mom found out that the neighbor had gone down the year before and filed whatever papers to claim that 8 acres as his, and if she hadn’t gotten a lawyer immediately she probably would have lost it by now.
You know, I had no idea from the OP that the guy had anyone living with him.
Are you on decent terms with his wife?
Somewhat, but distant. She is friendly and chatty when engaged and always returns waves when i drive or walk by. Her husband doesn’t, and he has a reputation as the neighborhood grouch.
On the other hand, he is not all bad. When we get serious snow (we’re on a dead-end street that doesn’t tend to get plowed until last) he’s the guy who clears the street, and sometimes even driveways.
chiroptera, it sounds like your are making the correct moves. Don’t forget to document everything. Everything. It seems that your belligerent neighbor not only has a problem with alcohol, but may be armed as well.
Document, document. Even what is called a contemporaneous notes. To your self. Date it, and document actions. It’s a lot better than “I think it was last Saturday”.
It sounds like you might have a good corner control for your lot. That it measures correct is good news.
If you have a sidewalk on the street side, look for something. Sometimes a + chiseled into it. I’m doubting that you have a sidewalk though, not as the property is described.
Understand that while the math for surveying is spot on, sometimes the control to measure from is not. If you talk to a survey company, make sure to explain the situation. You may need more than an Improvement location survey (ILC), based on what I have read and considering the size of the lots and we are only talking about two feet on a large area.
But -
An Improvement Location Survey (ILC) may be all you need to back your neighbor down. You may very well have one in your mortgage papers (I used to draw up about 15 of these ‘surveys’ a day). Check for it. It would give the closest distance from your house to all property lines (give or take) It may be enough.
Does anyone else find it astonishing that there are two parallel fences two feet apart?
mmm
You should also check your town’s bylaws regarding fencing. Typically, a fence has to be a specific distance away from the property line and can’t be built ON the property line. We recently put a fence up and it had to be a foot off the property line. We had a relatively recent survey in hand (from an unrelated matter) so we were confident it was being placed correctly, but wouldn’t have been without that.
From what I’ve read, that isn’t the case - there appears to be some feet of no man’s land plus two feet of the OP’s land between the two fences.
I’ve seen it.
I find it most surprising that this is supposed to make it easier to mow the grass.
She might be your ally in all this and might be your best bet to save you from rebuilding a fence.
On the one hand you might be able to say “do you think you could keep him at bay, at least when the grand kids are over, my son/daughter, almost called the police when he was yelling at the grandkids and they didn’t know what was going on, they want me to put up a big privacy fence in the backyard now but I told them I’d talk to you” That makes it looks like this isn’t something you want to do, but but they’re forcing your hand and you’re getting pressure from other family members to deal with the situation. Kind of a roundabout way of saying ‘personally, I don’t care of he’s a loud mouthed jackass but the rest of my family does’. Not true, I know, but it takes the blame off you.
On the other hand, my guess is that he probably acts like an ass all over the place and she just does damage control but doesn’t even attempt to curb his behavior because he’s not actually going to change his ways.
That’s not the way the OP describes it. I have to admit, I’m confused why you’d puit up two fences just two feet apart too.
He asked you to put up a fence inside your boundary, then he went and planted trees in the gap between his fence and yours. He’s trying to take possession of that strip of land. The next thing will be him taking his fence down.