Here is a run down of what the pellets did after having them in the coop fom June 2011 until April 2012. No smell.......I did not change any pellets although in February I did shovel about 4 five gallon pails of broken down material out as it was piling up pretty good and getting into their water. As the pellets break down they expand so I am going to guess you will wind up with about 15% more material then you started with. A friend of mine tried this method but didnt lay pellets in deep enough ( I had about 8+ inches, she had about 3 inches) and she did get an amonia odor which I never had.
Pellet pros - Inexpensive to use, stays clean, no stink, chickens seem to like it and they can scratch in it easily. It also acts as a good insulater and is very absorbant. I had no damp or wet bedding at any time.
Pellet Cons- Dusty when they break down.
When I cleaned the pellets out this wekend I found they were dry, easy to shovel with no mess at all. After I shoveled them out into my wheel barrow I used a shop vac to vac down the coop. I had no wet or damp material anywhere in the coop. Not all of the pellets were broke down, many were just swelled up in the corners.
On another note I do believe that a daily rake back and forth is well worth the effort and became part of my daily regiment in about Decemeber. I always raked what was left for droppings under the roost under each morning. Nothing too tough just a little raking to turn it over, the girls did the rest. I have 10 girls in case anyone is wondering.
I am going to switch to Pine shaving and see how that works. If it fails I will go back to pellets as I know they work. I am going to try the shavings with the same guidelines under which I used the pellets and see if the material has an effect on things or not. My guess is the pellets will turn out to be a better performer but I am going to find out......... I learn so much from this site I thought I would report my results so that others could see how deep litter and wood pellets worked for me.......
From Northern NH