We all just stayed in the main barn shed.. they put a soda machine in there and lots o f cover
That's what i tried last night. The only (preventable) problem with it is the guys with their backs to other side of the entrance. Sometimes the 2 at one end of the shed are too patient so when enemies flood through their side, enemies they don't take take out asap hit the guys with their backs facing them.
The only way to beat that is to pop 3-4 at a time when shit gets heavy. You might take a bullet or 2 if you aren't fast enough with the aim but it works with a solid group that knows this.
I never used the roof but EVERY time I try the boneyard without Sicc, 2 people take the roof, get kicked and leave me and the other dude hanging alone in the shed lol It's fucking gay. You can almost be sure that if 2 guys take the roof you're lucky to see wave 5.