How to build floating deck over tiles?

Rick3

I plan to build a low level merbau deck, app. 3.6 x3.6m, over a level, well drained existing tiled courtyard. It will not be attached to the house or any structures. I am flexible with the height but had in mind using 90x45mm, H3 joists/bearers <500mm apart installed as close to the tiles as is practically possible. I had thought of laying the frame directly on the tiles which would be wonderfully simple. Understanding this may not be ideal for ventilation and drainage around the timber members, I was thinking about elevating the frame with tiles every 2m. Would appreciate thoughts on this.

EricL

Hello @Rick3

Thank you for sharing your question about your decking project. I suggest having a quick look at these guides - How to build a low-level deck by @Adam_W and How to build a deck by @MitchellMc. These guides will help you what to take into consideration when designing your decking frame. I also recommend having a look at this discussion - Low-level composite deck over concrete and soil by @oninpena. It's a good example of a single level deck held in place using brackets and pedestal footing.

My best advice is the more space you can provide under your deck the better the air circulation. I propose doing a preliminary sketch on paper and sharing it with the community along with any other questions you have about your build.

I also recommend having a look at the Bunnings deck building guide:

If you need further assistance, please let us know.

Eric

Rick3

See attached my planned structure. It will be all 90x45 timber on plastic blocks sitting directly on a mostly level well drained tiled area. Is 2m spacing ok for the plastic blocks? Are noggins needed? Also attached a pic of the area

MitchellMc

Hi @Rick3,

It looks like your pictures didn’t come through with your post. You can try editing your post and using the little camera or landscape icon to attach them. If that still doesn’t work, feel free to send them directly to workshop@bunnings.com.au, and we can add them for you.

Regarding your deck, 90x45mm timber will need much closer support than every 2 m. Typically, joists should be supported roughly every 1 m, so 2 m spacing is too far for the frame you’re planning. As for noggins, they aren’t strictly necessary for a small 3.6 × 3.6 m deck, but adding them will increase rigidity and help prevent any movement or twisting in the joists, which can be beneficial over time.

Let me know if you have any more questions or if you manage to get the pictures attached, and we can provide more detailed guidance.

Mitchell