Posi-joists (2024)

Here is the moment every homeowner falls in love with Posi-Joists: the plumber arrives. Or the electrician. Or the HVAC technician.

For the contractor, Posi-Joists are a logistical dream. They are lightweight (one person can easily carry a 5-metre joist), arrive precut to length, and sit perfectly level on the wall plate. No more hunting through piles of warped, twisted, or crowned timber. And because the open web allows air to circulate freely, there’s less risk of condensation or dry rot in sealed floor zones.

So next time you walk across a room that feels unnaturally still, with no creak and no shudder, remember: the secret is hiding in the steel zig-zag below. That’s the Posi-Joist, doing its silent, brilliant work.

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.