Optimising decking board gaps for safety and drainage in public spaces

Whether you are building a raised deck or you are inspired by these ground-level deck ideas, there are some installation must-dos which cannot be skipped, especially if the system is destined for public use. Find out in this quick guide why gaps in timber decking matter, how wide they should be, and installation tips to achieve the best possible finish in your public space.

The Importance of Decking Gaps

Public decking areas have to withstand a lot of wear and tear. High traffic and footfall will influence deck design, while accessibility considerations are likely to dictate your timber choice and finish. The gaps in timber decking have the same importance, particularly when it comes to the safety of your public deck, boardwalk or communal walkway.

With the correct gap sizes, water can run off the deck quickly and easily to prevent slips and reduce the risk of accidents. Everyday debris, such as leaves and grit, also has the chance to escape through appropriately sized gaps. Tripping hazards are minimised too. Timber decking expands when wet and without gaps to expand into, boards will buckle and lift.

Drainage and Decking Board Gaps

For public decks based outdoors, rain, humidity and water runoff are key considerations. Gaps prevent the pooling which causes slip hazards. The presence of standing water can significantly shorten the deck’s lifespan with the wood becoming increasingly saturated and prone to decay, rot and fungal growth.

Gaps effectively make decks self-draining, minimising maintenance and improving performance in the short and long term.

Recommended Decking Board Gaps

When installing timber decking, there are two gaps to consider – the side gap and the end-to-end gap. The side gap refers to the spacing between each board, while the end-to-end gap is the spacing between the board ends. A standard side gap should be approximately 5mm. End-to-end gaps should be between 3 and 5mm for most hardwoods and 3 to 6mm for the majority of softwoods.

How Gap Sizes Vary Between Timber Types

The gap sizes for your public decking project may vary based on the type of timber selected. The density, grain, stability and shrinkage value of the timber will influence the side gap size. Here are the recommended spacings for the most common decking timbers:

• Softwoods: Pine, Spruce and Cedar boards are generally installed with 5 to 6mm side gaps.
• Hardwoods: More stable, denser Iroko, Jatoba and Balau shrink less but still expand when wet making a gap of 4 to 6mm more suitable.
• Thermally modified woods: These have much greater stability and can be installed with smaller gaps.
• Composite decking: A gap of 5 to 8mm is advised.

The width of decking boards may also make a slightly larger gap necessary. Boards measuring more than 90mm wide require a 7 to 8mm gap.

Best Practices for Public Deck Installation

There is an art to installing decking with accurate and consistent spacing. Firstly, note the condition of the boards and your surroundings. Whether wet or dry, you must account for the timber’s moisture content during installation and leave appropriate gaps accordingly. Pre-finishing the boards with oil or sealant before installation is recommended.

We advise the use of spacers or a hidden-fixing system to prevent uneven gaps and encourage good air flow.

Source Timber Decking Boards at EcoChoice

For safe, user-friendly public walkways and decking areas, our timber boards offer reliable solutions. Start your timber decking order today.