Low-level decking over concrete with extension

[spongebob2173]

Hi guys,

Just looking for some advice on how to go about building a low level deck off my existing alfresco.

Area is 4x3.2 at the moment but we are looking to extend it to 6x4m. One issue Im worried about is the height between the concrete and the sliding door which is 70mm

Would appreciate some instructions plans and materials needed if possible.

 

[Jason]

Welcome to the Bunnings Workshop community @spongebob2173. It's great to have you join us and we trust you'll get loads of helpful advice and inspiration from our clever and creative community. Apologies for the slow reply. 

Have you seen the guide How to build a low-level deck by @Adam_W? It would be a great place to start. 

Let me also tag our resident Bunnings D.I.Y. experts @EricL and @MitchellMc to assist you.

Jason

[EricL]

Hello @spongebob2173

Thanks for sharing your question about low-level decking over a concrete extension. If for example, you used Treated Pine Outdoor Timber Framing 90 x 45mm and turned it with 90mm end facing up. You then add the thickness of the decking panel itself. If you use Ekodeck it would have a thickness of 23mm. So 45mm plus 23mm equals 68mm. This would leave you an air gap of 2mm. Ideally, you would want more, if rain or moisture were to enter the area it will greatly shorten the life of your deck. 

Let's say for example you used timber decking panels instead. It would be 45mm plus 19mm which would equal 64mm. You would then have a 6mm air gap. In order to line it up with your sliding door, you would need shims to lift the frame and use angle brackets to hold it in place.  

Have a look at these amazing low-level deck projects that our members have shared here on Workshop.

• Low-level deck with steps and lighting by @asifkhawaja

• Low-level deck over concrete by @Backyardtradie

The first link is very similar to your condition with a cement slab near the sliding door.

If you need further assistance, please let us know.

Eric