We are looking at building a deck, 7m x 3.6m. would it be correct to use 140x45 for the bearers and joists, spaced at 450mm and posts along every joist at every 2.6m?
Welcome to the Bunnings Workshop community @tais. It's a pleasure to have you join us, and many thanks for your question about joist spacing.
Your 450mm centres are spot on, but posts at 2600mm would be right on the cusp of 140 x 45mm span capabilities. I'd be more comfortable with the posts being spaced between 2000 and 2400mm apart. If you max out the span capabilities on a deck, it can end up being a bit spongey underfoot. There's nothing worse than a bouncy deck.
Please let me know if you have further questions, and feel free to start a discussion about your project so we can all follow along.
Thanks for the reply @MitchellMc would it be overboard to use 190x45 for ledgers, bearers and joists? Thanks
I believe the trade-off is weight, although you can use the large timber pieces it makes the decking frame heavier which means that you'll need to make sure that the ground you are installing on will not settle or sink. I propose staying with the 140x45 as it provides you with that balance of strength and weight.
If you need further assistance, please let us know.