For coop and run floor you will want to plan to have some sort of carbon to add regularly. Ammonia from chicken manure builds up fast. Hay, leaves, straw, wood shavings, etc are all carbon. Some work a LOT better than others.
The important thing is the carbon: nitrogen ratio. This is what is going to determine the level of ammonia in the coop. Joel Salatin created this list in his book Salad Bar Beef:
“Carbon: Nitrogen
Poultry Manure 7:1
Leaves 50:1
Straw 100:1
Sawdust 500:1
Wood chips 250:1
Grass hay 80:1
Alfalfa hay 20:1
"Enough carbon must be put in contact with the manure to chemically suspend the nutrients. The rule of thumb is, if you can smell ammonia, add carbon."
The items with the highest numbers do the best job of sequestering the nitrogen and stabilizing the nutrients particularly ammonia (nitrogen). The point of sequestering/stabilizing nutrients is to hold them for composting and returning to the soil.
Keeping ammonia sequestered is crucially important for chicken health. They are right down there in it and it affects their lungs quickly. If you can smell it at 5’ up, image what it is at the source.
Now THAT is some awesome information! Thank you! I think @burntoblog has recommended some material by Joel Salatin as well. I'll have to pick up a book or two of his :)