If you re setting a post into soft ground or in an area that receives high winds it s always a good idea to bury your posts a little deeper and add more concrete.
Fence post depth code.
The depth of the post hole needs to be 1 3 to 1 2 the height of your fence.
Keep the height of your fence in mind when digging your post holes.
For a fence a little heaving is not easy to notice and does not destroy the servicability of the fence.
For example a 6 foot tall fence will need at least 2 feet of post in the ground.
Common construction requirements include post size spacing and depth.
Gates require a hole with a depth of 36 to 40 inches in the ground and with a diameter of at least 12 inches.
For example a 6 foot tall wood fence may need 4 x 4 or larger posts spaced no more than 6 feet apart and buried in the ground at least 2 feet deep.
For a structure it is important since any cracks caused by heaving will destroy the servicablity and appearance of the structure.
Frost line by zip code.
Here are a four tips to help you find the correct fence post hole depth.
Building codes and ordinances in your area may stipulate a legal depth and diameter for fence post holes.
You need to dig a 12 inch wide hole for a 4 foot wood post.
That is why there is a specified depth for building footings.
As a general rule of thumb you ll need to place at least 1 3 the height of the post in the ground.
The depth of your post hole plays a key role in the strength of your posts.
The code frost depth is meaningless for a fence.
Check your frost line by zip code or address using this map from the national weather service.
If not conventional rules of thumb offer a reliable guide.
If your post is 6 feet tall you will dig down at least 2 feet.
Others leave that up to the builder.
The maximum frost line depth is 100 inches as seen near the tip of minnesota north dakota and alaska all the way to zero inches in florida southern arizona and southern california.
It s a lot harder to push over a post that s buried deeply so always keep that in mind.
Some cities say posts must be set in concrete.
If the map isn t accurate enough for you.