I would suggest raising the doorway to a height of a least 12" to allow access to the coop after a DL of at least 6-8" is established. Also I have found that swinging the door to open out helps with the DL. I would use aged wood chips at a depth 6-8 inches with other materials such as leaves, grass clippings, garden waste, mixed in, as the DL decomposes add more of these same materials to maintain the depth of 8-12 inches. I have found this system to provide the healthiest and cleanest bedding system possible for my flock. The end result after the wood chips and materials have broken down provides some of the greatest compost for gardens and flower beds, the manure is broken down in a natural way and can be applied directly to your garden or flowers. You will be amazed to see how the bedding stay's dry at the surface after a rain quicker, and the odor is controlled by the depth of the DL. If ammonia odor is detected just add more wood chips or the other materials to correct the balance and let the worms, and other good bugs process the manure.