What is a Board on Board Fence?
A board-on-board fence (also called shadowbox fence) is a privacy fence style where pickets are mounted on alternating sides of the horizontal rails. Each picket overlaps the gap between the pickets on the opposite side, creating a fence that provides privacy from direct viewing angles while allowing air circulation and appearing finished from both sides.
This style is popular because it looks the same from both sides, making it a "good neighbor" fence. The overlapping pickets block direct line-of-sight while the angled gaps allow wind to pass through, reducing wind load compared to a solid fence. This can be important in high-wind areas and may affect local building code requirements.
Material Calculation
Recommended Materials
| Component | Common Size | Material |
|---|---|---|
| Posts | 4x4 or 6x6 | Pressure treated or cedar |
| Rails | 2x4 | Pressure treated or cedar |
| Pickets | 1x6 (5.5" actual) | Cedar, PT pine, or composite |
| Fasteners | #8 x 2" screws | Stainless or hot-dip galvanized |
Installation Tips
- Set posts in concrete at 1/3 the total post length depth (minimum 24 inches).
- Use a string line for straight alignment and a level for plumb posts.
- Mount rails with the wide face vertical for maximum strength.
- A 1" to 1.5" overlap provides good privacy while allowing airflow.
- Use exterior-rated screws, never nails, for long-lasting attachment.
Frequently Asked Questions
How much overlap should I use?
A 1" to 1.5" overlap is standard. More overlap increases privacy but uses more pickets and reduces airflow. Less overlap saves material but reduces privacy. At 1.5" overlap with 5.5" pickets, you achieve good privacy from most viewing angles.
Is board on board more expensive than solid fence?
Yes, board-on-board uses approximately 50-70% more pickets than a solid fence because pickets are mounted on both sides. However, it provides a finished look from both sides (no "ugly" side) and better wind resistance, which can justify the added cost.
What post spacing works best?
8-foot spacing is standard and matches common rail lengths. For 6-foot tall fences in high-wind areas, consider 6-foot post spacing for added strength. Never exceed 8 feet between posts for fence heights over 4 feet.