Join the fence with the neighbor’s; Can’t use his post..how to dig the hole for mine close to his

fencepost

As shown in the picture my neighbor's fence is already in place (the vertical fence) Mine will be horizontal and I need to set the post as close as possible to his. My post will support a gate (72" long)

His post (white) is already rotten and it is moving.
What options do I have? How do I dig a hole next to his post (set in concrete)
enter image description here

I don't think that his post will be enough to support everything. One option will be to extract his post, to replace it and to add a new one for myself and bury them both together in a large hole. Would this work?

Best Answer

I would (and have) set your post at least 2' from his. So it would end up looking like this

 -        -
| | -----| |-------------------
| | |    | |                  
| | |    | |                  
| | |    | |                  
|A| | B  |C|          D       
| | |    | |                  
| | |    | |                   
| | |    | |                  
| | -----| |-------------------

A = neighbors post

B = your fence panel cantilevered beyond your post

C = your post

D = your gate/fence...

If you set your post too close to his, then both posts will end up being influenced by the other...as one leans/sinks it will more likely affect the footer of the post immediately next to it.