Posi-joists ((link)) ❲Tested & Working❳

They are not magic. Posi-Joists are typically deeper than solid timber for the same load (a 300mm Posi-Joist might replace a 220mm solid joist), so you lose a little more headroom. They are also marginally more expensive upfront. But when you factor in the hours saved not drilling holes, the money saved on service drops, and the lifetime of a stiffer, quieter floor, the math quickly flips.

At its core, a Posi-Joist is a hybrid. It consists of strong, solid timber flanges (top and bottom) connected by a sinusoidal or zig-zag steel web. This “I” shape gives it incredible strength-to-weight ratio. But unlike a traditional I-joist (made of OSB), the open steel web of a Posi-Joist is its superpower. posi-joists

Because of their engineered design, Posi-joists can span much further than a traditional solid timber joist of the same depth. Want a 6-metre wide living room with no intermediate support wall? A Posi-Joist can handle it without the bounce or the “trampoline” feel of cheaper alternatives. The steel web distributes loads evenly, meaning fewer vibrations, less squeaking, and a floor that feels like concrete—solid, silent, and secure. They are not magic