Do wooden fence posts require concrete?

Question

I plan to install a wooden fence using 8-foot 4x4 posts connected to wooden panels. All of the lumber is pressure-treated.

My plan is to set the posts in holes that are about 3 feet deep (below the frost line where I live).

My question is: Do I need to pour concrete into the holes when I install the posts, or can I simply set them in the soil? And if I use concrete, should I pour the concrete into the bottom of the post hole first, let it set and then install the posts on top of it? Or do I pour the concrete around the post within the hole?

I can't find a clear answer anywhere about whether you actually need concrete in post holes.

Answer 1

It's really a matter of preference. Concrete is much stronger and will defend better against the elements. Here is a Home Depot link on how to properly install fencing.

Answer 2

I have not had a problem backfilling with sand using water to help pack it down. I have also used the precast concrete forms ; they are roughly 8" cubes with an inset for a 4 X 4 in the top. I put them about 4" down into the soil to be sure of no movement.