we are building an 8x12 coop with 2 rooms. a sm room for storage and 8x8 for the kids. we are insulating the walls. but not sure what to do with the roof. if we insulate it will we hold too much moisture? we have 5 windows and 2 vents up by the roof. this will be my first winter. i have 4 large breed chickens and 10 silkies. the outer part of the roof is plywood and shingles. should the inside be another layer of plywood or insulation or neither?