FenceChoose the intended privacy pattern
Side-by-side boards form one row. The selected gap controls visible openings and board quantity. Board-on-board overlaps neighboring boards across two alternating planes. It uses more timber and requires a fastening arrangement that matches the rails and board thickness.
For side-by-side construction, a clear bay width W uses approximately round up((W + gap) ÷ (board width + gap)) boards. An overlap pattern uses round up((W - overlap) ÷ (board width - overlap)). These are ordering estimates; edge details and the actual alternating arrangement must be checked.
For W = 2.31 m, 0.14 m boards and a 0.01 m gap, the single-row estimate is 16 boards. With a 0.025 m overlap, the overlapping estimate is 20. Check shrinkage, rail loading, fastener lengths and access to both sides. Gate infill is counted separately.