Yes it will make the gate posts stronger and less likely to move. The
gate posts are subject to more stress than the other posts because the
swinging gate puts lateral stress -- and especially if you have a
spring on there, the post that it bangs into gets stressed. So the
arch is a good idea; you may need longer posts for that to give enough
headroom. Even better, structure wise, is to use some more posts and
make it into a little arbor.

How deep you put the posts depends in part on your climate, you need to
get below the freeze line. I had to set mine about 3 feet deep
(Chicago area) and so I had to get 10-foot posts, which irritatingly
cost about 50% more than 8-footers, and then cut a foot off the top of
them, but I didn't want to risk having them not deep enough.

-- H


The ground does not freeze here, so there is no freeze line issue. Well, on
really cold winters the ground may freeze down to a few inches :P

I gather from other comments that 8 foot posts set 2 feet deep in concrete
is adequate, and that 8 foot spacing is also adequate.

Any suggestions about what to do about sag? I see a lot of fences with 8
foot spacings that tend to sag over time. I've thought of adding a small
support in the middle of the run, that would certainly stop the sag.

Lastly, and info and suggestions on how to mix the concrete that the fence
posts are set in? Premix? Buy sand and gravel and cement?

Are there any good fence building web sites that covers this basic stuff?