Shipping Container Turbine Vent Installation

Just added a roof vent to my 40ft container to help with heat buildup as well as condensation control. I used a scrap piece of 1 inch thick plywood for the main frame and made some fillers from some 1x4s. I coated the pieces with flex seal rubberized coating before installing everything. The 1x4s were cut with 42 degree angles to fit the contours in the roof.
I pre-drilled holes in the roof to allow me to run screws up into the plywood from the bottom side, then installed the Whirlybird Turbine per the manufacturer's instructions.