I'm trying to plan to build a low level deck and need some help. The clearance off the ground would be about 250mm and for this reason I was thinking of just running Joists from the back of the house. I'm wondering if I use H3 treated pine 190mm * 45mm joists and fix directly into concrete flooting
with stirrups or existing slab with Dyno bolts. Would this be sufficient enough? If this will be okay, how far apart should I drop footings? Every 1.8m? I will be running the joists every 450mm and using the joist hangers.
Welcome the Bunnings Workshop community @Olin. It's great to have you join us and many thanks for your question.
There are a variety of stirrups that you can use for this purpose when bolting directly into the concrete slab. I would be inclined to think posts at 1200mm-1500mm centres would be appropriate for 190 x 45mm treated pine timber. You might need to look at some span tables to get direction on whether 1800mm is appropriate. Let me mention the ever-helpful @Adam_W to see if he would like to join the conversation. Adam has recently put together an article on How to build a low-level deck which I trust you'll find useful in your project.
If you can provide the dimensions of the deck I'd be happy to post a basic layout for you.
Please let me know if you need further assistance or had any questions.