Why Precision Measurements Matter in the Metroplex
In the open prairies of Forney, Wylie, and Rockwall, your fence isn’t just a boundary—it’s a giant sail. A standard 8-foot privacy fence can catch thousands of pounds of wind pressure during a North Texas thunderstorm. If your posts are too shallow or spaced too far apart, the leverage will snap the wood or bend the steel.
At Fence Supply Inc., we use specific engineering standards designed to combat our unique combination of high wind loads and expansive clay soil. Use the charts below to plan your post layout.
1. Post Depth Chart (The Foundation)
The depth of your post is the most critical factor in preventing “fence lean.” In Texas clay, the deeper the post, the more stable the “anchor” becomes against the soil’s seasonal movement.
| Fence Height | Minimum Post Depth | Recommended “Pro” Depth | Hole Diameter |
| 4 Feet (Ornamental) | 18 Inches | 24 Inches | 6–8 Inches |
| 6 Feet (Standard) | 24 Inches | 30 Inches | 8 Inches |
| 8 Feet (Privacy) | 30 Inches | 36 Inches | 10 Inches |
| 10+ Feet (Commercial) | 48 Inches | 60 Inches | 12+ Inches |
2. Post Spacing Chart (The Span)
Spacing determines how much weight and wind pressure each individual post has to carry. Shorter spans are always stronger, but they require more labor and concrete.
| Fence Style | Post Material | Max Spacing | Recommended Spacing |
| 6′ Side-by-Side | 2-3/8″ Steel | 8 Feet | 8 Feet |
| 6′ Board-on-Board | 2-3/8″ Steel | 8 Feet | 7 Feet |
| 8′ Side-by-Side | 2-3/8″ Steel | 7 Feet | 6 Feet |
| 8′ Board-on-Board | 2-3/8″ Steel | 6 Feet | 6 Feet |
Note: “Board-on-Board” fences are much heavier and catch more wind than “Side-by-Side” fences, which is why we recommend a tighter 6-foot spacing for 8-foot tall projects.
3. Corner and Gate Post Requirements
Corner posts and gate posts are “terminal points” that handle tension from two different directions.
- Gate Posts: Because a gate is heavy and constantly moving, the gate “latch” and “hinge” posts should always be set 6 inches deeper than your standard line posts.
- The “Double-Bag” Rule: We recommend using double the amount of concrete for gate posts to ensure the frame never sags or pulls the post out of alignment.
4. Adjusting for Soil Conditions
- Rock/Caliche (North Collin County): If you hit solid rock at 18 inches, you may not be able to reach the 30-inch depth. In this case, you must increase the width of the hole to create a wider “footing” to compensate for the lack of depth.
- Wet/Low-Lying Areas: If your fence line sits in a drainage easement that stays wet, you must go deeper. Wet clay loses its “grip” on concrete, making shallow posts much more likely to fail.
Pro-Tip: The “Above Ground” Height
When buying your posts, remember to account for the depth!
- For an 8-foot fence: If you are going 3 feet deep, you need an 11-foot post.
- For a 6-foot fence: If you are going 2 feet deep, you need an 8-foot post.
- Always leave about 2 inches of the steel post extending above your top rail for the strongest connection.
Ready to Calculate Your Order?
Now that you know your spacing and depth, you can determine exactly how many posts and bags of concrete you need for your project.
