How to calculate deck bearer span?

[ajenks]

G'day all

Just in the planning stage of our deck and was querying whether or not I am reading the Hyne bearer span tables correctly.

Due to existing landscaping issues with where the deck with be situated, the posts/supports are required to be 4100mm apart.

So based off the Hyne bearer span table, I would require a LGL type beam sized at 300*65mm so ensure it meets requirements and can support the load of the joists/deck. Is this correct?

In the same line of questioning, am I able to instead of use such a large bearer, laminate two smaller bearers together instead?

Finally, in regards to the joist span tables, the span of the joists does not exceed 1800mm, based off the Hyne joist tables, I could use MGp10 at 140*45mm comfortably?

Thanks, the span tables took me a while to get my head around

Cheers 

[MitchellMc]

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

You are correct with those timbers. 300x 65 for the bearers and 140 x 45mm for the joists is suitable.

You could potentially laminate two smaller timbers together, but it can be difficult to find span tables that show laminated spans. Two 150 x 65 timbers do not necessarily equal one 300 x 65.

Please let me know if you have any questions.

Mitchell

[Jason]

Let me also extend a very warm welcome to the Bunnings Workshop community @ajenks. We're pleased to have you join us and look forward to seeing your deck project come to fruition.

For the benefit of other readers of this discussion, I just wanted to add that we have a guide that should be useful when planning a new deck: How to understand deck span tables.

Jason