How Far Apart Should Decking Joists be?

When creating a beautiful, functional and versatile outdoor space, it's essential to look at solutions that are easy to install, add value to your home and elevate the style of your garden. You can achieve all these goals and more with high-quality garden decking.

One crucial aspect of getting the most from your decking project is ensuring the joists are installed correctly, but what is the correct distance between joists?

Generally, joist spacing for decking boards should be no greater than 450mm, with a recommended spacing of 400mm. It's crucial to ensure that each board is evenly spaced along the length of your decking, creating an even, level walking surface whilst supporting the rigours of foot traffic. There are plenty of other ways to make sure your decking joists are correctly installed, such as firmly fixing them into place with screws that are not over-tightened. We run through all of these tips in more detail, and more, below.

Choosing the Right Material

Selecting high-quality materials is essential for the longevity of your decking. Opt for pressure-treated or naturally rot-resistant wood, like cedar or redwood, to minimise maintenance and ensure durability against the elements

Adequate Ground Preparation

Before installing your decking, ensure the ground is level and well-prepared. Clear any debris, weeds, and rocks, and if necessary, lay a weed-resistant fabric to prevent weed growth from underneath the decking.

Use Double Joists for the Perimeter and Joints

To strengthen the edges and prevent warping, consider using double joists for the outermost framing of the decking and at any butt joints. This added support will enhance the overall stability and aesthetics of your deck.

Protect Against Water Damage

Water is one of the biggest enemies of decking. Apply a waterproof sealant or a water-repellent preservative on your wood before installation to protect it from moisture and extend its lifespan significantly.

Optimal Deck Board Placement

Position the deck boards perpendicular to the joists for better weight distribution and enhanced stability. Ensure consistent spacing between each board allows for natural expansion and contraction due to temperature changes.

Hidden Fasteners or Deck Screws?

Choose between hidden fasteners and deck screws based on your aesthetic preferences. Hidden fasteners provide a clean look with no visible screw heads, while deck screws offer easy maintenance and replacement if needed.

Leave Even Gaps

Leave small gaps between deck boards to allow for water drainage, preventing water from pooling and promoting better air circulation, which reduces the risk of rot and mould growth.

Regular Maintenance

Proper maintenance is vital to keep your decking looking beautiful and in top condition. Regularly inspect for loose boards, damaged joists, and signs of rot. Clean the deck annually and reapply sealant as needed to protect the wood from weathering.

Installing a decking involves several critical considerations, with joist spacing being a key factor for structural integrity. By following the tips outlined in this blog, you'll ensure a successful decking installation that will not only look stunning but also provide a safe and inviting outdoor space for years to come. Remember, attention to detail during installation and consistent maintenance will reward you with a beautiful, long-lasting deck that enhances the beauty and value of your property. And if you're looking for decking joists then be sure to look up our range. 


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