Decking on a patio concrete slab

[Nathan88]

Hi All,

just got to know about posting our topic as I have commented on other topic and the admin team directed me to post a new topic.

I’m planning to build a merbaur decking on our patio concrete slab as in the photo. The slab area is 3.6 x 9 m and it is sloped with low of 150 mm and high of 300 mm to the indoor floor. I would like to have the decking same level as indoor which leaves me 150 mm spacing from concrete slab near brick wall and 300 mm spacing on the far end of the patio area.

the other side of the patio opens to our rumpus room, which is same level as concrete floor.

Can someone help me to choose the framing and connections to concrete slab? Also, I would like to hear your opinions to manage the deck level to the indoor, while providing access to the rumpus room. 

[MitchellMc]

Hi @Nathan88,

I see you have already received a helpful reply from @HandyAndy which is fantastic.

Cost of timber is also a significant factor. On the last layout, you have 25 meters of 120 x 45 as the bearers. If you were to run the bearers perpendicular at a 450mm spacing you would end up using 81 meters of 120 x45. You'll also need to join them together to reach the 9 meters length required.

If you were to just run the bearers perpendicular to the decking boards and have no joists then the overall cost might end up less. My examples are just for reference and somewhere to start your plan.

Please let me know if you need further assistance or had questions.

Mitchell

[bruce93]

Hi @Nathan88, @MitchellMc, @HandyAndy 

I'm not sure if I'm too late to the party but another solution you could use for your decking over the concrete slab is a product called KlevaKlip joist Support. 
They aren't a bunnings product unfortunately but are available throughout Australia and are great for doing decks on concrete slabs as they allow you to level the joists regardless of the fall on the concrete slab...

Also using these would not require the use of bearers. https://www.klevaklip.com.au/images/WordDocUploads/KK_BP_P3A4%20April%20_AJS.pdf

I've attached a photo of it in use for a deck I built for my mum back in last February and then a completed picture of the deck. 

Let me know if you have any questions.

[UncleAz]

@MitchellMc Great information.  I am planning my deck currently and this has been most helpful.  I was wondering if there is a site that you use for the diagrams in your posts?  Is this a planning tool that you have available?

Thanks.

[MitchellMc]

Welcome to the Bunnings Workshop community @UncleAz. It's fantastic to have you join us and many thanks for your question.

The site I use for the diagrams is https://www.blocklayer.com/deckcalculator.aspx and is not associated with Bunnings. Please be advised I use this tool as a visual aid to get people started in the right direction when constructing a deck. All relevant building codes need to be followed and you should not rely on this layout tool solely. A qualified builder or structural engineer can assist you in checking your plans before commencing a build.

We look forward to hearing more about your decking project and would encourage you to start your own discussion if you would like detailed assistance or would like to share with the community.

Mitchell

[UncleAz]

Thanks for the information.  Really appreciate it.  I will start a new discussion shortly.  

[Just_Me]

Hi,

I'm planning to build a deck over a concrete slab alongside my house.  If I use the Builder's Edge Pedestal feet to support the bearers, do I still need to attach the deck (or at least the first bearer) to the house, or can it just be freestanding on the Pedestal feet?  The deck will be about 4.5m x 3.5m.

Thanks.

[Jason]

Hi @Just_Me,

Thanks for joining in the discussion. It's great to have you join the Bunnings Workshop community.

I will ask @MitchellMc to assist you when he is back on the site tomorrow. Let me also tag decking expert @Adam_W to see if he might like to share his thoughts on the pedestal feet in the meantime.

Feel free to post anytime you need a hand or have something to share. We're looking forward to seeing how your deck project comes together. Perhaps you might like to hit the Start a discussion button so you can document your progress and share it with the community.

Jason

[MitchellMc]

Hi @Just_Me,

The pedestal feet are great for supporting the deck's weight but don't add much regarding structural rigidity. I'd encourage you to frame in the ends of the joists with additional timber, which will tie everything together and stop the joists from distorting. I've created the image below to illustrate. Alternatively, you could add a ledger board to the house and connect the joists to it.

Please let me know if you have more questions. We're here to help.

Mitchell

[Just_Me]

Thanks for your replies and nice picture.  I like the idea of boxing it with additional timber rather than attaching it to the house.  It will be a lot easier in my opinion.