We're in the middle of building our first chicken coop, which is actually our first time creating anything with wood. I'm wondering how you make the roof for external nesting boxes so that the roof hinges upward to get the eggs out. Do you cut the edge of the roof at a slant so that it fits against the wall of the coop at the angle? Or do you put a plank against the coop that the egg box roof attaches to? How do you keep a seal between the roof and the coop so that water doesn't get in? Instructions and pictures would be hugely appreciated. The hens arrive in two weeks! Thanks.