fence
My next door neighbor has a drive way and the council workers have put a gate up (looks like 6ft fence panels). The post that is next to my fence has simply been drilled through my fence and into a post I have. The post is not sunk or anything just drilled into my fence with three screws.
Will what they have done weaken my exiting post? Is what they have done suitable for a 6ft gate?
The main con is that since its designed to be driven down, the tapered tip will offer less torque, even set in concrete, than a post set to a similar depth.
Another consideration is frost heaving. The bare adapter should not heave, but the combined concrete/adapter might, unless the pour goes below the frost line. This can be mitigated with SONOtubes use.
I wonder if using 2 ez-mender, set in concrete, might not give a more stable base.
(from the website: "Post bases do not provide adequate resistance to prevent rotation about the base and therefore are not recommended for non-top-supported installations such as fences or unbraced carports")
A general rule (not sure if your neighbors abide to it) is to build the fence 1-2 feet inside your property line. You mention that the fence post is presumably in their property so even butting up to it would be in their yard. You best option is to ask them to join your new fence to it and get a simple contract to protect yourself. Either that or put up all four sides in your property.
You may also need to get a permit or permission from city/municipal/HOA depending on your location. Your neighbors could have even blocked you from getting a fence because of easement right between yards, all things to look up before this endeavor.
As for the height difference, it's more personal preference than anything else. Personally I'd recommend one size fence for the front of your preference and one size in the back of your preference which may or may not be the same. Like if you want front privacy but have nature in the back, it allows you to get away with 6ft in the front and only 4ft in the back. I'd mainly recommend the same size in both front sections if your yard is level otherwise it will look off from the street.
In the front you may want to fade the height difference but I wouldn't even bother in the back. Could be a nice design feature if it fades into a gate post or something.
*Adding images:
Best Answer
Fences usually have posts of 2 sizes or grades.
Line post are smaller diameter and not as well braced, as they support only fence.
End posts are larger and better braced for extras like gates. They are meant for tensioning chain link fences.
If they've attached to a line post, it will probably not support a gate for long.
I would insist that they support the gate with a properly braced post ( usually involving concrete).