Fence Post Installation: Concrete, Depth, and Alignment Simplified

Same core questions as the previous article—concrete vs. dirt, 30" vs. 36", laser vs. string. Here's the condensed, field-tested answer:

Concrete Is Non-Negotiable

Tamped earth rots posts. Period. Use dry-mix concrete (Quikrete or similar).

Depth: 36 Inches

Deeper hole = better lateral stability, frost protection, and post life.

Save Concrete: Add Rock

Place large stones in the bottom 12–18" of the hole before pouring. Displaces volume, locks the base.

Alignment: String Line Beats Laser

1. Set first and last posts plumb and at correct height.
2. Run a taut string line between them.
3. Set intermediate posts to the string. Done.

No laser needed. No post level needed if you brace each post two ways while the concrete sets.

One more thing: check local frost depth. In some zones, 36" is minimum; in others, 42" or 48".