What joist size to use for low-level deck?

[Zog]

Hi everyone. I have assembled the framing of the modular decking for my low level deck (see photos). What is in the photo is essentially a walkway, the main deck will be under the pergola and slightly higher. I've gained some confidence from what I've done so far and am considering using tuffblocks and building a framework rather than using the modular decking for the main deck. My question is just about the joist size. I'm not going to use a bearer and joists system, just a framework of joists, mainly because the Pergola is already there (before I bought the house) so I need to preserve the ceiling height of the pergola as much as possible.

I'm unsure about joist size and span of tuffblocks. The Tuffblock website has an article where they're using 2"x6" (45x150) joists, I've seen joists of 45x90 used in Australian based articles and the joists of the Good Times modular panels from Bunnings are 45x70. I'll probably use 140x19 merbau decking.

The pavers will be staying, they're not perfectly level, a small part of the deck will be on soil (the far sides in the second photo).

The total size of the main deck will be about 6.4m x 7.4m or 47.36 m2. It's a lot bigger than any articles I've seen about building a  low level deck. Any advice will be much appreciated.

[EricL]

Hello @Zog 

I strongly suggest doing it in sections and at your own pace. 

Please keep us updated with your progress, we look forward to seeing your deck panels installed.

Eric

[Zog]

Hi @MitchellMc 

after having a holiday I'm back to working on the deck and have a question.
there are horizontal screws in the framing and when screwing the decking boards on the outer edges of the walkway the decking screws are hitting these horizontal screws and the same thing will happen on the main deck. I've tried to find a shorter Simpson strong-tie 12G, eg a 5.5x35mm that I could use on the outer boards, but couldn't find anything. Is there a shorter suitable screw that has a similar looking head (so that mixing them won't look too bad) ? I've cut a few screws shorter but it is very time consuming (more than 100 screw) and a shorter screw would be easier.