Let's go!

Using high quality timber decking joists are vital to ensuring that your decking lasts for many years and doesn’t start to bend, sag and subsequently begin to rot or even collapse over time. Determining the joist’s strength, durability and spacing can be vital to the success or failure of your decking project.

Whilst timber decking joists are the element of the decking project that you don’t see, they are in fact one of the most important parts of the decking structure. However, many projects assume that because the joists are never seen, there’s no need to pay attention to their specification and therefore end up buying cheaper non-durable softwood options which could also jeopardise the safety of the decked area in just a few years. What’s more, together with the hassle and labour, the cost of replacing rotting joists includes lifting all those beautiful hardwood deck boards and potentially damaging them in the process.

As a general rule, go for joists that are as durable as possible. This will usually mean going for timber that is suitable for Use Class 3 or Use Class 4. If pressure treated, please ask for service life guarantees. Ecochoice can also supply you with dense, strong and durable FSC® certified joists in a range of species to help the longevity of your decking project. By focusing on their performance instead of looks, we can deliver you with alternatives that will also be very cost effective.


The distance between the joists will also ensure your deck area is stable and safe to walk. Here’s an example of span tables for C16 softwood:

For further details on how to install your decking, please click here to check out our simple decking guidance sheet.

If you’d like to discuss your project in more detail, including water-based decks such as piers and pontoons (we supplied all of Hastings Pier decking and joists), please contact us by clicking the email or call us buttons below.

If you’d like to discuss your project in more detail, including water-based decks such as piers and pontoons (we supplied all of Hastings Pier decking and joists), please contact us on 03456381340.

Joists related insights

How can we help?