hi I'm having problems with the design of my coops roof. i want to use a metal roof panels. the coops foot print is 12x12. i have seen a lot of people using flashing around the whole coop. Is this a need of just something to make the roof look cleaner. I have looked at a lot of different designs on the site and finally went with the Wichita cabin coop because of the look and where mine is going worked out well. i just blew it up to be a little bigger. suggestions i have never really built a roof before this is quite the adventure.