How to build a deck partially over concrete?

[abison]

Hi All, I'm in the process of planning for a deck as shown in the photo below. I'm planning to use Ekodeck boards. As you can see in the photo, the deck partially sits on concrete slab and the remaining part sits on the ground. For the portion on concrete, i'm planning to use 90x45mm bears at 1.5m spacing (shown by green lines) and joists of 70mm at 450mm spacing (shown in blue). I need some advice on the framing on the ground as there is 100mm height to the deck level and there is no room for the bearers. Also need some information for footing in ground. I'm not sure If i have explained my question clearly. I have added a pencil sketch plan showing the levels for better understanding.  

deck concept

[Akanksha]

Hello @abison, 

Welcome to the Bunnings Workshop community. We see you've been a member for a while now so it's great to see you make your first post.

Many thanks for asking that question on building a deck. It sounds like an exciting project. I'm sure @EricL would be happy to assist once he's online later in the day. 

Akanksha 

[Akanksha]

Hi @abison, 

To add onto my note above, I also recommend checking out our fantastic decking resources which contain handy tips on building a deck, including @Adam_W's How to build a low-level deck. You may also find plenty of inspiration in our Top 10 most popular deck projects and Inspiring low-level deck builds.

Other decking resources on the Bunnings Workshop site include:

• How to build a deck
• How to select decking timber
• How to build a decking boardwalk
• How to stain and protect decking timber
• How to renovate a timber deck. 
  
  

The Bunnings team has also created a seven-part series on how to build a deck, starting with how to plan out your deck, that you may find useful. 

Let us know if you have any further questions. We'd be happy to assist. 

Good luck with your deck build.

Akanksha

[EricL]

Hello @abison

Your deck framing plan looks great, I suggest having a quick look at this discussion - Low-level composite deck over concrete and soil - by @oninpena. If you're building a single-level frame, I suggest using Builders Edge Pedestal in combination with pavers. As for the area over the concrete slab, I recommend angle brackets to mount the frame.

The Builders Edge Pedestal comes in three sets and can be adjusted to different heights and would be perfect for your ground installation. The angle brackets are usually installed by using Dynabolts. 

If you have any other questions we can help with, please let us know.

Eric   

[abison]

Thanks, @EricL for your response and suggestion. If I use a Builder edge pedestal with pavers, will there be any settlement in the ground because of water? What about shallow footing for these? 

On concrete I can use bearers and joists as the clearance from the slab to the deck is approx 240mm.

[MitchellMc]

Hi @abison,

The Builders Edge pedestal feet need to be placed on a compacted surface. The pavers are great at spreading the load, but you'll still need to ensure the soil is compacted. Also, if there are any existing drainage issues in the area, you should address them to ensure any water can freely drain away from the area.

You might like to lay some Road Base over the soil and hire a compactor to run over the area. This will leave you with a compacted substrate ready for pavers and feet.

You could install a shallow footer, but if you're going to go to that extent, you might as well use stirrups and full-sized footers.

Please let me know if you have further questions.

Mitchell

[abison]

Thanks @MitchellMc 

With the Builders Edge pedestal feet, what is the distance between each pedestal? 

[EricL]

Hello @abison

I suggest a distance of 1-meter between pedestals on a single joist, each joist must have a pedestal foot on it so that the entire decking frame is supported.

Eric