I have received conflicting advice about how to set wooden fence posts.
- Many web sites suggest setting them in a concrete cylinder.
- Someone at the local hardware store had seen posts set in concrete rot and break because water seeps in along the edges of the post (especially in the winter) and does not drain properly. He suggested crushed rock (what I would call gravel, see Definitions of various sand, gravel, and rock products) instead.
- A local fence company said they just set the posts in compacted dirt, but use 5×5-inch posts.
What is the best way to set fence posts in different climates, given that the wind force on a 6-foot-tall privacy fence can be substantial?
Best Answer
Last summer we rebuilt our fence using advice from The Fence Bible. The advice was great, and the directions clear. The author covered both concrete and compact dirt/rock footers for wooden fences. I'd highly recommend it to anyone building a fence for the first time.
Concrete does risk rotting the wood because of water build up, but that can be mitigated with proper drainage. Dirt footers can be problematic if you have very loose dirt in your yard. Dirt requires lots of work with something heavy to compact it; concrete requires mixing and handling concrete.
We set ours in dirt/gravel and realized it was exactly the right choice when our fence was hit by a car 4 months after we built it. The car shattered two 4x4 posts, a gate, and several rails, a 3rd posts was pulled from the ground, and every other post along the run tilted about 5 degrees including a 6x6 corner post; 10 posts had to be reset in all. Our neighbor (whose fence was also hit) had concrete footers, which were pulled from the ground, or shifted several inches but left in the ground. His footers had to be removed and replaced, and all new posts were required. We had to replace the damaged parts (2 posts, a gate and several rails), but we could reset the others. If we'd had concrete I suspect more would have broken, and we would have been unable easily reset any that had tilted (granted fewer might have tilted but that energy had to go somewhere, hence the assumption about more broken posts).