Bearers for Ground Level Deck

[pfuller]

I have 70X70 treated pine lengths that i'm considering using for bearers for a ground level deck. Can i get away with using them for the bearers and 90X45's for the joists. Or would 70X70 be way too light?

Any help appreciated.

[addo]

There's nothing in the span tables (AS 1684) with a bearer that shallow.

With a close enough spacing (somewhat less than 450), you could probably make it suitable for light usage, but a depth of 90 or greater is advisable. It's then a matter of balancing cost and ease of construction.

Regards, Adam.

[pfuller]

Thanks Adam!

[Dr - 307]

If the 'bearers' were spaced close enough why would there be an issue? It's not traditional / common practice but it would work if that's what you've got to work with.
Or swap it around and use the 70/70 for joists and 90/45 for bearers.

[echnidna]

Its far more practical to use the correct timber for bearers.

Smaller stuff can't span as far so you have to put more stumps in the ground.

[Dr - 307]

That would be my thinking also. Gotta do it proper. Half assed jobs always end up biting you on the backside.