i want to build a floating deck how do i do that and what is the cost?

Answer 1

You can do this with very little expense. You can pick up shipping pallets for the surface. Use large 2X4's to screw or nail them together on the underside. Get some empty metal drums. Weld the tops shut. Tie the drums securely to the underside of your deck.

And then you have a floating deck for maybe $50!