The Long & Short of Fence Posts
If you've ever built, or planned to build, a fence, then you've probably run across the issue of how long your fence posts should be; particularly if you weren't using a pre-fabricated system. With little to no experience, choosing the right length fence posts can be a confusing issue. Luckily, there is an easy to remember rule of thumb that many professional fence installers use to determine the height of their posts.
If you follow the guideline above - for most standard fence systems - your posts should be deep enough to provide strength and stability for your fence. However, if you live in an area of high wind or extreme cold, you may want to opt for a longer post, because it will make your fence less vulnerable to the elements. On the other hand, if you are installing an light ornamental system in a low wind area, then you may be able to get away with shorter posts; although longer posts won't hurt.