How to build a new low-level deck - 7.5m x 2.7m?

nm193

Hi,

I'm looking to build a new low level deck in our backyard. 

I've been looking through the bearer and joist spacing requirements as per this guide (Availability of F7 Pine, Treated and Untreated) and have come up with the layout below. Just looking for some advice if the spacing are okay or if I need to be more conservative? Will I need a bearer in the center to support the load or can I get away with a 2.68m bearer span?

MitchellMc

Welcome to the Bunnings Workshop community @nm193. It's wonderful to have you join us, and many thanks for your question about timber spans.

As per the document you've provided, under the joist section when spaced at 450mm centers for 140 x 45mm MGP10 timber, we see that the max single span is 2600mm. So, although your frame is supported adequately at 1800mm, your joists are right on their (slightly over) maximum span. I typically would never suggest someone build at the maximum span, as being more conservative will lead to a stronger deck. You could get away with your plan, but once you start adding heavy items to the deck or entertain a crowd, your deck is going to be of the minimum specification required.

I'd recommend adding a bearer down the middle for additional support.

Please let me know if you have any questions.

Mitchell