Low profile timber decking over concrete

https://www.workshop.bunnings.com.au/discussion/comment/10823#Comment_10823

Hi @Jason ,

Thanks for your response. I went through some of the examples here. They were quite useful for my initial plan. I thought post this get more advices from the experts in here.

Apologies if I am repeating the same.

I added below site picture too for more information.

Thanks

Dilanka

https://www.workshop.bunnings.com.au/discussion/comment/67795#Comment_67795

Hi @Dilanka,

I'd also like to welcome you to the Bunnings Workshop community.

Your joists are both running down the slope and across the slope and you'll likely need to use two different fixing methods to suit.

For the highlighted area here:

I believe a simple solution would be to use Good Times 100mm Modular Decking Adjustable Support Feet. In order for the foot section to match the slope of the concrete, you will need to drill a hole at a slight angle into the joist. Alternatively, you can just continue with the L brackets but longer versions similar to Carinya 100 x 100 x 50 x 4.5mm Zinc Plated Angle Bracket. They will still function the same but will be at an angle on the sloping section. I'll illustrate this on an image below.

For the highlighted area here:

You might need to use Builders Edge Pedestal Feet and plastic packers to accommodate for the angle of slope. Alternatively, you could cut sections out of the sloped slab and concrete in Pryda Post Anchor Half Stirrup Solid Stem 300mm M10.

The only other thing to mention is that you need at least 10mm under your joists for ventilation of the deck structure.

Well done on completing such an extensive plan and we look forward to seeing you get started on your project.

Please let me know if you need further advice or have questions.

Mitchell

https://www.workshop.bunnings.com.au/discussion/comment/96746#Comment_96746

Thank you so much your response.

Those details are really useful. While I am going through in details, I got few more questions as well.

1. In my previous drawing I missed noggins between last two joists as shown below. Can you confirm number of noggins I used are too many or just enough?

2. As you proposed, if I am using Builders Edge Pedestal Foot, part of the base will come out from the joist and it won't be able cover using a vertical cladding. Do you have any suggestion for that?

I am drawing the final structure now and If I get any issues I'll come back to you.

Thanks

Dilanka

https://www.workshop.bunnings.com.au/discussion/comment/115016#Comment_115016

Hi @Dilanka,

There have been a few members that have built decks within the community that haven't used noggins at all. One popular example would be @Neo19's Merbau decking over concrete slab. You could afford to eliminate some of those noggins and I have illustrated that below. Instead of removing the noggins I've suggested, you could just space them all further apart. I believe one every 1.2m would be sufficient.

I apologise as I'm not sure what you mean by "part of the base will come out from the joist and it won't be able cover using a vertical cladding".

Mitchell

https://www.workshop.bunnings.com.au/discussion/comment/125327#Comment_125327

Thank you so much.

Sorry about my bad explanation on item two. Please check below image. Hope that will be clear.

In this case I won't be able to cover the base of the Builders Edge Pedestal Foot .

One more thing to clarity, what will be the spacing required between Carinya 100 x 100 x 50 x 4.5mm Zinc Plated Angle Brackets?

Thanks

Dilanka

https://www.workshop.bunnings.com.au/discussion/comment/132249#Comment_132249

Hi @Dilanka,

I would suggest using the angle bracket method on the opposite side to the cladding board. Place the bracket as below but on the other side.

A spacing of every one to one and a half meters would be suitable for the brackets.

Mitchell

https://www.workshop.bunnings.com.au/discussion/comment/136467#Comment_136467

https://www.workshop.bunnings.com.au/discussion/comment/136467#Comment_136467

Thanks for your information. I'll update you the progress.

Thanks

Dilanka

https://www.workshop.bunnings.com.au/discussion/comment/139373#Comment_139373

I got few more questions when I am working on final drawing. Can you please give me some recommended numbers for following;

1. Spacing between two 90x19mm Merbau Decking boards

2. Spacing between two joist (when decking over concreate)

3. Spacing between Brick wall and the deck

Thanks

Dilanka

Jason

Hi @Dilanka,

@MitchellMc will be back on the site tomorrow (Friday) to assist you. Please let us know if you are in a hurry for this detail and I can tag other members who might be able to assist.

Thanks,

Jason

https://www.workshop.bunnings.com.au/discussion/comment/141319#Comment_141319

Hi @Jason

Thanks for your response. That's alright, I'll wait for @MitchellMc .

Dilanka

https://www.workshop.bunnings.com.au/discussion/comment/139373#Comment_139373

Hi @Dilanka,

A would suggest an initial gap of three millimetres between Merbau decking boards. Once you screw in the first board you can tap three millimetre thick nails next to it to create the spacing before laying the next board. When the next board is fixed into position you should remove your nails and continue the process across the deck. The boards will shrink over time and the gap which was three millimetres will increase to around five millimetres.

Between the middle of one joist and the next a spacing of 450 - 600mm would be suitable.

A gap of ten millimetres between your last joist and wall of your house would be sufficient. It just needs to be large enough to accommodate swelling of the timber and water drainage.

Please let me know if you need further information or have questions.

Mitchell

https://www.workshop.bunnings.com.au/discussion/comment/141320#Comment_141320