I am installing a tongue and groove deck on a craftsman style front porch. The front porch is pitched away from the house and has a 1/2" plywood underlayment. I have flashed the entire inside area and created drain holes on the face of the porch. I plan to waterproof the wood with tuff rubber. Once I am done, I am not sure how to secure the planks. I'm afraid if I nail it, the nails will pierce the waterproof layer, rendering it ineffective. I was thinking using strips of self-adhesive flashing where I will be nailing. Also, I'll need a solution to let the water flow underneath the flooring surface. What should I do?