How to install Ekodeck above pressed concrete?

[lynnetonychloe]

Hi there

We have a small area of unattractive pressed concrete paving from our backdoor to our garden/grass area and we are considering building an Ekodeck on top. The concrete gets surface mold especially when it has been raining meaning we need to pressure wash it currently.

Questions:

• We have been recommended steel joists but we're also concerned that the concrete would continue to get mold under the deck - is there a treatment for the concrete we can use beforehand please?
• The deck will be flush to the house door and Ekodeck post a recommendation for a height of building a deck 90mm above concrete is that correct please? https://www.ekodeck.com.au/installing-ekodeck-over-concrete/

[MitchellMc]

Welcome to the Bunnings Workshop community @lynnetonychloe. It's terrific to have you join us, and many thanks for your question about constructing a deck.

You are correct that the minimum recommended distance under Ekodecking to a non-draining surface is 90mm. If water drains freely off the concrete and doesn't pool then you can reduce the height to 40mm.

All exterior concrete surface experience some form of algal build-up. Typically it's not mould but moss or algae and is not harmful. There's no chemical product I know of that will inhibit algae or moss growth for a prolonged period of time. However, I also don't think you should be concerned about any growth under the deck. 

I'm keen to follow along with your build, so please keep us updated.

Let me know if you have any questions.

Mitchell