Description Decking Joists Pressure treated decking joists. 3.6m x 47mm x 100mm (12ft x 4″ x 2″) These decking joists are the most common sized framing timber for decking. They provide a solid structure for fixing your decking boards too. When making your decking frame you should use a 400mm spacing between your timber joists. Decking joists can screwed or nailed together. All of our fixings can be found here. If you are constructing a decking project which is raised high from the floor, we would recommend using 6″ x 2″ timber joists instead. These larger joists can be found here along with our decking boards and accessories. 6 x 2 Timber joists. Decking provides an elegant and cost affective way to landscape your garden. Kudos Fencing are stockist of quality pressure treated decking boards sourced from Scandinavian redwood timbers. Our deck boards are 120mm wide x a sturdy 28mm thick. We offer timber joists used for decking frames of sizes 4 x 2 and 6 x 2 in 12ft lengths. We have a new range of decking accessories such as anti slip decking plates, balustrade spindles, newel posts and hand rails. Decking screws and balustrade brackets are also available. Take a look through our range of decking and accessories, add to your cart, then view your cart to calculate shipping or collect from our trade counter in Swindon Wiltshire. Trade and general public welcome.