My research has shown that fence posts should be dug to a depth of at least 1/3 of the height of the post—for a six foot fence, the post depth would be 3 feet.
I purchased a 6 foot vinyl privacy fence from Lowe's, and the manufacturer's recommended post was a 5"x5"x8' post, an entire foot short of what I would have expected. Indeed, Lowe's doesn't even appear to sell a 9 foot fence post (without routed holes). Should I return the 8 foot posts and find something longer? Or is there some way to approximate a longer post (e.g. concrete+rebar going deeper or something?)?
- My soil is extremely rocky (on a mountain in Utah County), but otherwise loamy.
- It's not usually windy, 40 mph sustained winds with 60 mph gusts would be the strongest wind you might see in a year. Most of the length of the fence will separate my house and the neighbors, about 20 feet away from either house, which I'm hoping should should act as a windbreak.
- The frost line here is 36 inches
- I'm planning on using concrete to set the posts.