We recently bought a little farm which came with an established 8'x10' coop. We opted to buy the 21 chickens that were residing in the coop primarily because we wanted to give them better care. (We do have experience raising/spoiling small flocks of 6 or fewer hens). They had no roosts, nor proper nest boxes, both of which have since been remedied. The chickens are approx. 25 weeks old and appear to be in good health. Our biggest hurdle is this--From what we can tell, there has never been any proper bedding on the coop floor. It appears as though the previous owners were doing the deep-droppings method--no litter, no cleaning. Ever. The floor consists of several inches of partially decomposed droppings which reeks of ammonia. The coop has cracks along the roof, and exit to the run, and a fairly large window, so we don't think ventilation is the problem. From what we can tell, the coop is several years old and has probably housed several large flocks of birds. We have started shoveling out the floor, but there seems to be no end in sight. Our goal was to get rid of all of the dirt/droppings and then add pine shavings. Do we need to get rid of all of the old droppings/floor, or just get rid of a few inches and start adding pine bedding? Neither we nor the chickens want to breath that anymore!