Board-on-Board Fence Calculator

Board-on-board (also called shadowbox or alternating) fencing uses pickets mounted on both sides of horizontal rails alternately. From any angle, you see the edge of one board and the face of another, creating privacy without being solid on either side. Unlike standard privacy fencing where boards touch edge-to-edge, board-on-board allows for better airflow and a more attractive look from both sides. It uses roughly twice as many pickets as standard fencing because one side covers the gaps of the other.

Board-on-board fencing requires approximately twice the number of pickets as standard spacing fencing. For a standard fence with pickets 5.5 inches wide spaced 3 inches apart, you need about 1 picket per 8.5 inches of fence length. For board-on-board, pickets are typically spaced 4-6 inches apart (double the standard spacing), with the back row centered on the gaps. This means you need about 2 pickets per linear foot of fence for standard 5.5-inch pickets with 4-inch gaps.

The ideal spacing depends on your picket width and privacy needs. Common spacing: 3-4 inch gap between pickets on each side. The pickets on the opposite side cover these gaps. Formula: Gap = Picket Width / 2 for equal shadowbox effect. So for 5.5-inch pickets, a gap of 2.75 inches creates balanced spacing. For more privacy, use 2-inch gaps; for more openness and airflow, use 4-inch gaps. Test a small section first to confirm the visual look suits your preference.

Board-on-board fencing typically costs 60-80% more in materials than standard privacy fencing because it requires roughly twice the number of pickets. However, it offers advantages: looks good from both sides (no "good side/bad side"), better wind resistance (wind passes through gaps), less prone to warping (air circulation on both sides dries boards evenly), and longer lifespan due to better ventilation. Consider using cedar or pressure-treated pine for longevity.