How to build deck on concrete using Ekodeck boards?

[hans01]

Hi All,

I m planning to build deck in a concreate floor small area (3m x 2.6m). I am kind of new for decking projects. I want to use ecodeck boards which has 23mm thickness. The problem I have is that the clearence to build deck is only 100mm. So with the board thickness taken away I have only 77mm left.

For framing the only option I can think of is 70mm x 45mm framing treated pine H3 (are there joist hanger available for 70 x 45 timber?).

What should I do to prevent the frame from decaying as the frames will be touching the concrete floor?

[MitchellMc · Accepted solution]

Welcome to the Bunnings Workshop community @hans01. It's wonderful to have you join us, and many thanks for your question about creating a low-level deck.

It's not a great idea to place your H3-treated timber directly on concrete as they are only rated for above-ground use, not on-ground use. Any pooling water on the concrete will cause early decay of the timber. Also, you should know that having little to no airflow underneath the deck structure will shorten the deck's lifespan.

No 75 x 45mm joist hanger is available, so you'll need to screw through your frame into the end of your 70mm joists. 

To assist in inhibiting decay on the joists you could coat the bottom of them with a bitumen-based paint. This coating will stop them from sitting directly in any water. I'd recommend that you use that last 7mm to mount your brackets under the joists instead of next to them. This will raise the timber slightly off the ground. You'll need to use brackets and countersunk Dynabolts to get them to fit within the 7mm gap.

Have a read of this article on How to build a low-level deck and please let me know if you have further questions.

Mitchell