Share
Attaching some photos and hopefully to give you an idea what I'm talking about. 
Welcome to the Bunnings Workshop community @LeoL. It's fabulous to have you join us and many thanks for your questions.
Ekodeck recommends a minimum of 90mm ground clearance. You will also need a gap between your joists and the tiles of at least 10mm. This would require you to place the joist on their 45mm side, and I would recommend Treated Pine Outdoor Timber Framing 90 x 45mm. You could use 70 x 45mm timber on edge. However, I have never heard of someone constructing a deck from such a small size.
An issue that you must address is the area off the patio. There is not enough clearance between the joists and the soil to construct a deck here. In the guide How to create a low-level deck by @Adam_W, he lists some requirements when constructing a deck with minimal clearance to the soil. If you are not able to remove some existing soil, then you should use H4 or H5 treated timber. You'll need to special order these grades of timber.
Tuffblocks are designed for posts or joists standing on their 45mm edge. As you'll be laying your 90mm timber on its side, you won't be able to use Tuffblocks. Once you decide what you are going to do with the excess soil, then I trust we will be able to provide solutions for your posts.
Please let me know if you need further help or had questions.
Mitchell
Hi Mithcell,
Thanks for your reply.
Yeah I know it's just a small space but my main objective is really to get rid of the grass (as much of it for less maintenance) and to have more space for outdoor area. As you can see the existing patio is only 4.8 x 1.2m.
Anyways, while reading about your suggestion and thinking about this whole project. I realised that I'm wasting money covering an existing new tiled patio. I'm now thinking of just installing the composite deck off the patio (grass area). I believe the Alpine Ash composite deck colour appears to be very similar to my existing patio. So it's just gonna be like an extension rather than a whole composite deck. I know I have to make enough space and I'll have to take out those soil to accomodate the Tuffblocks with the joist standing on 45mm. It's been raining the past days so that could possibly go to my favor.
I'm still into Tuffblocks so if I decide later to cover the patio, then I just need to put a 90mm post to the existing tuffblocks point to increase the height and to level it to the patio area. Is this a good/right idea?.
Thanks and regards,
LeoL
That certainly sounds like a good plan @LeoL.
My comment about never hearing of someone constructing a deck from such a small size was in regards to the size of the 70 x 35mm timber you are using for the joists. Not the size of the overall deck. I believe the deck will be a perfect size to increase your outdoor space.
Please let us know if you have further questions or need help.
Mitchell
Hi @LeoL,
How are you going with this project and did you need any further assistance?
I'm really keen to see the transformation of your outdoor space and think it will look excellent.
Mitchell
