Plans call out on a flat roof with pods (flats of preplanted plants)to slope insulation to drain.The plans have I joists with decking epdm and ridgid insulation not on sleepers to bear the weight equally.Do you actually step and shape the foam to make it drain properly? Also the parapet wall 11 inch high has steel railing penetrating the metal cap.should I solder boots into the metal cap and counter flash around each post?It says seal all penetrations.Trying to flash correctly for longevity.Thank you in advance Pell