Can we install joist in flat position for low-level deck?

[VicK]

Can we use 75x45 H3 pine for decking joist in flat position?  I mean, place timber in such a way that I will have 45mm as height. 

Does this reduce structural strength of frame?

[JacobZ]

Hi @VicK,

A warm welcome to the Bunnings Workshop community and thank you for your question.

Unfortunately, you can't use 70x45 H3 pine in any orientation as a joist. 

Check out the Hyne Timber Joist Span Table alongside How to understand deck span tables and How to understand deck components for some guidance.

If there is a particular scenario you are looking for a solution to, I'd be happy to assist further if you can add some more details.

Let me know what you think.

Jacob

[VicK]

Thanks @JacobZ .

i am trying to build deck over paved backyard. I have only 95mm height clearance for deck. 

I don’t want to remove pavers and I am not sure if decking tiles is a gud idea. 

[EricL]

Hi @VicK,

Let's do a bit of quick math, if you are using 70x45 it means that you'll have 20mm left for the decking panel. The standard Merbau decking panel is usually 19mm which leaves you technically with 1mm. Not enough as an air gap for under your deck. Turning the 70x45 is not recommended either as the strength of the timber piece is in the tall 70mm section.  

If there are tiles or pavers that can be removed to provide more space, then the 70x45 should fit in nicely.

Here is a link to ideas and inspiration: Top 10 most popular deck projects

If you have any other questions we can help with, please let us know.

Eric

[VicK]

Thanks @EricL

really appreciate it