I want to build a deck coming off at the second floor level. There will be a porch below that will need to be dried in. I am considering a torch down roof to waterproof the second floor deck. I would like to have a composite deck on top of the torch down surface. What would be the best way to install the deck so as not to compromise the roof surface below? Or, is there a better way to achieve the second floor deck and have it waterproofed below? Thanks for your help!