How to build a timber deck over existing concrete patio?

[AshleyDickey]

Hello, 

We're looking to construct a timber deck over our existing timber patio along with new railing and aren't too sure where to start or how much it may cost. We're just looking at tools and materials at this point as we have a family friend who will help us build it. 

Dimensions are 5 x 2.7, not sure on the height yet but we're not too high, maybe less than 10cm? 

[EricL]

Hello @AshleyDickey

Welcome to the Bunnings Workshop community. It's wonderful to have you join us, and thank you for sharing your question about your low-level deck.

Nothing is more satisfying than walking on a deck you built yourself. I suggest having a look at this guide - How to build a low-level deck by @Adam_W. This guide will give you the necessary information you need to consider when making your decking plan. The cost of your deck will highly depend on your decking plan. This includes the timber frame size, footing size, screws, bolts and decking panels you'll be using.

My colleague has recently made a deck building guide - How to a build a deck by @MitchellMc. This guide will provide you with a sample list of tools and materials you'll need to build a deck. 

In order to give you better advice, would it be possible for you to post a photo of the area where you plan to build your deck? We can then assess the condition of the area. Our members can then make recommendations on how to proceed. 

Bunnings has recently released a seven-part series on how to build a deck:

• 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.

I also suggest checking with your local council on the rules and regulations on building a deck near your property. 

We look forward to seeing the photos.

Eric

[AshleyDickey]

Hello, 

Thanks for the information, here's a few pictures. We've already got a patio, just wanting to put timber over the top and a new timber railing. 

[EricL]

Hello @AshleyDickey

Let's say for example you have a usable height of 100mm, if you were to use a timber frame of 70 x 45 that would leave you a space of 30mm. From that 30mm you need to subtract the thickness of the Merbau decking panel which is 19mm. The remaining space would be 11mm, it's this gap that will be at the bottom of your timber frame. In ideal conditions, you would want more, but if we were to raise your decking higher it will now become a tripping hazard to anyone coming out of the house. 

When you draw your decking frame plan, it's important to consider which direction the decking panels will be laid out. How you layout your decking frame will dictate which way the decking panels will face. This would also be a good opportunity to consider if you'll be building a picture frame or keeping it simple with a single panel border. These are some of the things you'll need to consider when making your initial plan. 

I suggest checking your local council for the rules and regulations on how high the timber railings should be. Here is a good example of a framing layout that you can refer to - Low-level Merbau deck over a concrete slab by @Neo19.

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

Eric