Last updated: January 2025

Herringbone Decking: Pattern Layout and Waste Guide

Herringbone decking transforms a simple garden deck into a striking architectural feature. The distinctive V-shaped pattern, where boards are laid at alternating 45-degree angles, creates visual interest and a sense of movement that standard parallel layouts cannot match. But this beauty comes at a cost — herringbone patterns require more boards, more cutting, and more careful planning than any other decking layout. This guide explains how the pattern works, how to calculate materials accurately, and how to minimise waste during installation.

Understanding the Herringbone Pattern

In a herringbone layout, short board sections are arranged in a zigzag pattern, with each board meeting its neighbour at a 90-degree angle. The effect is similar to traditional herringbone parquet flooring, scaled up for outdoor use. Each "chevron" typically uses boards cut to equal lengths, with the angle of the pattern running diagonally across the deck surface.

The pattern requires a modified joist layout compared to standard decking. Because boards run in two directions, joists need to support boards crossing at 45 degrees. This usually means closer joist spacing (400mm centres rather than 450mm) and may require additional noggins (short cross-pieces between joists) to provide support at the pattern intersections.

Why Herringbone Creates More Waste

Standard parallel decking wastes around 10% of material — offcuts from one end of a row can often start the next row. Diagonal layouts waste about 15% because edge cuts at 45 degrees create triangular pieces that are difficult to reuse. Herringbone wastes approximately 20% because every board is cut to specific short lengths, and the edge boards need compound angles that produce unusable offcuts.

The waste is not just from edge trimming. The herringbone pattern requires boards to be cut to precise, consistent lengths for the zigzag to align properly. Any variation in cut length will compound across the pattern, creating gaps or misalignment. This precision cutting means more measurement, more careful sawing, and more discarded pieces that are slightly too short.

Calculating Materials for Herringbone

Our decking calculator handles herringbone automatically — select the herringbone layout option and it applies the 20% waste factor to your board count. But understanding the manual calculation helps you verify the numbers and plan your cuts.

Start with the same area calculation as standard decking: deck length × width gives you the surface area in square metres. Divide this by the individual board coverage area (board width × cut length per piece). This gives the raw count of herringbone pieces needed. Then multiply by 1.2 (adding 20% waste) to get the total boards to purchase.

Note that you will typically cut multiple herringbone pieces from each full-length board. A 3.6m board can yield three 600mm pieces or two 900mm pieces, with offcuts. Planning your cut list before buying can help you choose the optimal board length and minimise waste. Some suppliers sell shorter offcut bundles specifically for herringbone projects.

Joist Layout for Herringbone

Herringbone patterns need joists at 400mm centres maximum — tighter than the 450mm standard for parallel timber decking. The boards cross the joists at 45 degrees, which increases the span between support points. With composite boards, which are generally less rigid than timber, 350mm centres may be recommended. Always check your board manufacturer's specifications for herringbone installations, as they may differ from standard layout guidelines.

You will also need a central spine board or joist running through the pattern to anchor the chevron points. This spine defines the centre line of the herringbone and every board angle references back to it. Getting this spine perfectly straight and square to the deck edges is critical — any deviation will be amplified across the pattern. For more on joist calculations, see our joist spacing guide.

Tips for Minimising Waste

• Create a detailed cut list before buying. Map out every piece needed and calculate how many pieces you can get from each full board.
• Choose board lengths that divide evenly into your herringbone piece length. For 600mm pieces, 2.4m boards yield exactly 4 pieces with no waste.
• Cut all pieces to length in batches using a stop block on your mitre saw for consistency.
• Save all offcuts until the project is complete — you may find uses for them in border strips or as spacers.
• Consider a border frame of parallel boards around the herringbone field. This simplifies the edge cuts and creates a clean visual frame for the pattern.

Cost Implications

A herringbone deck costs roughly 20–30% more than an equivalent standard layout, considering both the extra boards (20% waste) and the additional joists needed for tighter spacing. Labour costs are also higher if you are hiring a professional, as herringbone takes significantly longer to install than parallel boards. For a detailed cost breakdown, try our cost estimation guide or run the numbers through the calculator with herringbone selected.

Frequently Asked Questions