Concrete support + concrete surface is perfect for heavy usage. No worries on drop object onto surface, placing super hot pot/wok onto surface and etc.
That was exactly the qns I posted to my ID. He reply saying no problem, confirm no water leakage. BUT on the other hand, my uncles who are in carpenter line for over 20yrs, strongly object wooden support. They just say 1 sentence, "wood scare of water".
Maybe I will still remain solid surface but will request to build the concrete support w/o the concrete surface.