Fence posts - concrete or gravel?November 10th 2010
Q. I have some rotted fence posts to replace and I am wondering if it's best to cement the posts in the ground or if I can just fill with gravel? Also, how deep should I dig the hole? Typically, how long should a fence last before replacing?
A. In most cases setting a post 3-feet deep in the ground is sufficient. Typically, a fence post under normal conditions has a life of anywhere from 10-20 years; however, a lot depends on the environment of where the post is located. For the best installation use pressure treated posts with concrete post set in the bottom 4 to 5 inches of the hole and brace each post individually until concrete has set. Fill in around the post with good drainage material such as Pit Run Gravel and tamp with the end of a 2x4.
If the posts are being set 3-feet deep in the ground and are not treated, be sure to treat the bottom 3 feet of the post as rot starts at ground level. Ask your retailer for an environmentally friendly treatment. Staining your wood with a solid, semi-transparent or translucent stain will also prolong the life providing protection from exposure direct sunlight and excessive moisture.
Ensure you check your local building code for any height restrictions. Also, always call before you dig; whether you're putting in fence posts, planting a tree or excavating for a deck always contact your local utility company at least a week in advance to have your utility lines marked. There could be gas pipelines, electrical services, telephone and cable TV as well as water and sewer connections so be safe.