Can I install composite decking directly on top of concrete?
You can install composite decking on top of concrete but not directly. You would need to build a frame on top of the concrete similar to a normal deck. The framing could be smaller than normal, 2&quot; x 2&quot; and it would be secured directly to the concrete. The distancing of the &quot;joists&quot; would be the same as what the decking calls for. The reason for the frame is that the composite decking still need to be aired out. Your stairs would require the same type of framing. Stairs can be tricky so you'd want to check with local coded.
The problem you have with this procedure is that your concrete is all busted up and securing your frame to it correctly will be all but impossible unless you repaired it, which would be crazy.
You could build an entirely new deck over the concrete with a larger frame not supported by the concrete. Your best choice would be to remove the concrete and start fresh.