Second story application can be a little tricky for the DIY homeowner. But, for a well-seasoned Porch Pro, it is really a snap.
First: You have to decide if you are going to try to make the second story application water tight or waterproof. If you just need it water tight, you can follow the standard first story installation instructions. If you want to reduce the amount of water that can flow between the boards in heavy rain, you can use 100% silicone in between each board. This in conjunction with proper slope will all but eliminate the water from weeping between the boards.
Second: If you are going to make the application water-proof, make sure you use a peal and stick membrane that will gasket the fastener used when you penetrate it. On top of the membrane use a sleeper system.
Next: Install Aeratis with the desired fastening method. If you are using a nailer, use stainless steel L or T head nails. If you are using flooring stapler, use 2″ 1/2″crown 15 1/2 gauge stainless steel flooring staples and if you are using screws, use GRK #8 x 2″ stainless steel or coated trim-head composite screws.
Finally: Trim the edges and remove protective film and clean the surface.
Make sure you completely read the installation instructions before installing Aeratis. In the resources section, on the right hand side of the site, download waterproof installation instructions.