How to lay frame on concrete slab for decking?

[BAditya]

Hi I am planning to build a deck on concrete floor . The height of the floor is 44mm, so what height timber should i use to build a frame?

[EricL]

Hello @BAditya 

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. They will give you a very good idea of what's involved in designing a decking frame.

I'm sorry, but 44mm is not enough space for a low-level deck. For example, if you were to use 70mm x 35mm timber framing, it would have to be used on its flat side with the 70mm side pointing up. 

If you add the thickness of the decking panel which is 19mm and a timber spacer you would have a total thickness of 58mm which is 14mm taller than your available space, thereby creating a tripping hazard which is not ideal.

I can't recommend using smaller timber framing as they tend to warp and twist, especially when exposed to high moisture. If you can't find a way to increase your available space to at least 150mm, I can only suggest tiling or paving your concrete slab.

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

Eric

[BAditya]

Thank you Eric. i think i will use the flat side as you suggested. As per the image attached could you please advise how many timber do i need for frame?

[EricL]

Hello @BAditya 

Based on your measurements and on the condition that you are using 70x 35 x 3.6-meter lengths you would need 20 joists that includes the sides of the frame. Please note that you will need to adjust your drawing as the timber is only 3.6 meters long. If you were to add noggins, you would need an extra 7 lengths. 

If you need further assistance, please let us know.

Eric