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Hi I’m looking at starting a low level timber deck in a recently built house but just need some advice if I’m on the right track or someone to steer me in the right direction.
I’m thinking single height subfloor and will be built on existing slab and on ground. I have 160mm height to work with on the alfresco slab but can dig out some additional ground to get more clearance. Currently this is what I’m proposing.
- 120x45 wailer bolted into brick work
- 2/120x45 bearers (pink lines) supported by adjustable feet (on concrete) and posts in ground. I was going to span approximately 1600mm.
- 120x45 joists @ 450 centres in between bearers fixed with joist hangers. Max span 1500mm
- 140x19 spotted gum decking with 5mm spacing. Deck direction North/South looking at my sketch
- I will set deck out for a picture frame boarder
- On the natural ground laying approximately 50mm of stone to help with drainage.
Am I on the right track? Im not 100% sure on the spans and also the section of the deck on my sketch top left there will be a 600-700 cantilever I’m not sure will work.
I have also seen frames set up with just joists at 450 centres supported by feet and posts with noggins nailed in between.
I hope to get a start soon so thanks to anyone who replies!
Hello @benny4
Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about your decking.
Doing a bit of quick math 120mm plus the thickness of the decking panel which is 19mm will give you a total of 139mm. This means that you'll have a gap of 21mm underneath your decking frame. Please let me know if I understood your plan correctly. Have you considered using 90x45 for your decking frame? You will technically be using more timber pieces, but the gap underneath your deck turns to 51mm which is much better for airflow.
I suggest having a quick look at this discussion - Low-level composite deck over concrete and soil by @oninpena. It's an excellent example of a deck that uses 90x45 and mixed footing for the decking frame.
In regards to your questions, I propose building an independent/free standing deck with no attachments to your brick wall. In this manner it will not put any load or stress on your brick wall. To answer the rest of your queries, can I please request that you finish your decking plan with joists included. Can I also please ask you to put your measurements for the proposed footing locations. To help with your planning, I suggest having a look at these guides - How to build a low-level deck by @Adam_W and How to build a deck by @MitchellMc. These guides will give you very good ideas on what to take into consideration while planning your decking frame.
I also recommend having a look at the Bunnings deck building guide:
- How to plan out your deck
- How to set out a deck
- How to install stumps
- How to install bearers
- How to install joists
- How to lay decking
- How to add a step to your deck.
If you have any other questions we can help with, please let us know.
Eric
Hello @benny4
It's great you've received excellent advice from @JacobZ. Oninpena asked us about the footing positions at the time, and we actually suggested placing the footing to 1-meter to prevent getting a bouncy deck. At 1-meter distances the joist is very secure and stable. You'll also notice that the angle bracket footings were placed on opposite sides of the timber to provide even better stability.
For the soil section we suggested using pavers over the compacted soil and then the pedestal footings to go on top of them.
If you need further assistance, please let us know.
Eric
Okay so this is an updated sketch. Rough and not to scale but the basic are getting there I think. I’ll add in more framing on parts of the perimeter because I would like to make a picture frame decking. I think I can start setting it out and preparing the area over ground now. Thanks for your help so far @JacobZ @EricL im sure I’ll be touching base again with more questions as I progress
