Building a Board on Board Fence, How to Space Your Boards
How to Properly Measure Picket Spacing for a Board-on-Board Wood Privacy Fence
When it comes to a board-on-board fence, the goal is total privacy. Unlike a standard "side-by-side" fence that develops gaps as the wood shrinks, a board-on-board fence uses overlapping pickets to create a "3D" effect that stays private year-round.
However, getting that look right depends entirely on the math. If your spacing is off, you’ll end up with uneven overlaps or, worse, visible gaps. Here is how we measure it to ensure a perfect result every time.
1. Understand the "Overlap" vs. "Gap"
In a board-on-board design, you have a base layer of pickets and a top layer (the "battens") that covers the gaps.
- The Rule of Thumb: For a standard 6-inch picket (which actually measures 5.5 inches), you want at least a 1-inch overlap on both sides.
- The Math: This means the "gap" between your base-layer pickets should be roughly 3.5 inches.
2. Step-by-Step Measuring Guide
To get a consistent look across the entire run of your fence, follow these steps:
Step A: Measure Your Actual Picket Width
Never assume a 6-inch picket is 6 inches. Pressure-treated pine and cedar vary. Measure three or four pickets and take the average. If they are 5.5 inches, proceed with your layout.
Step B: Create a Spacer Block
Don’t use a tape measure for every picket—you’ll eventually make a mistake. Instead, cut a small scrap piece of wood to your desired gap width (e.g., 3.5 inches). This "spacer block" ensures that every gap in the base layer is identical.
Step C: Layout the Base Layer
Install your first picket plumb at the post. Place your spacer block against it, then install the next picket. Repeat this across the entire section.
Step D: Center the Top Layer
Once the base layer is finished, place your top-layer picket over the 3.5-inch gap. If your math is correct, you will have a 1-inch overlap on both the left and right sides of the top picket.
Pro Tip: For the base layer you can save time by cutting a spacer block that is the measurement of your picket width and the space you need to maintain the correct overlap. The just start at the beginning of your run and use the block to mark a line on your top stringer. The you can just place your base layer against that line and nail them on.
3. Why Proper Spacing Matters
- Shrinkage: Wood is a natural product. As it dries in the Florida sun, it will shrink. If your overlap is only 1/4 inch, that gap might open up in six months. A 1-inch overlap guarantees privacy even after the wood seasons.
- Wind Resistance: A board-on-board fence is heavy. Proper, even spacing allows for better structural integrity and weight distribution across your 4x4 posts.
- Visual Symmetry: Nothing ruins a high-end wood fence like having a 1-inch overlap at one end of the panel and a 2-inch overlap at the other.
4. The Gifford Standard
At Gifford Fence, we don't just "eyeball" it. We use precision spacers and stick-build our wood fences on-site to ensure that every board-on-board section is perfectly balanced, regardless of the terrain or the length of the run. We also prefer to use a smaller space between our pickets that will provide a greater overlap of the boards because boards are never cut straight and a bowed board with shrinkage can create a gap in the middle of the board that is unsightly.
