When setting a wood fence post in concrete, the bottom end of the post should be set in:

• A. Dirt
• B. A Stiffer Concrete Mix
• C. Sand
• D. Gravel

Answer: (D)

Setting the bottom of a wood fence post on a gravel bed provides a drainage layer that prevents moisture from being drawn up into the wood. Gravel drains well and creates a capillary break, reducing the chance of rot and decay that can occur if the wood sits directly on dirt or sand or if the bottom is encased in solid concrete. The rest of the hole can be filled with concrete to stabilize the post, but the bottom end benefits from the porous, drainer-friendly gravel. Dirt or sand would retain moisture or compact, increasing rot risk, and a stiffer concrete mix at the base would trap moisture against the wood.