@alexis187 I use a pond liner as a barrier. If the ground is wet, this will keep the bedding dry in a roofed area. Best, only costs $25 for 10x20 and no trench digging or concrete pouring! For bedding I use all purpose construction sand (coarse sand) with zeolite (neutralize ammonia) and diatemaceous earth (prevents mites). construction sand is under $5 for 60# a hardware store, even cheaper from landscape supply. Zeolite cost <$20 for 50# if you get it from a pool supply or artificial turf supply. If you get it from a pet supply or hardware store, they sell it $20+ for 5#. I ran out of zeolite and the turf warehouse is inconvenient to me so I am trying out Dry Stall which is a Pumice volcanic rock similar to zeolite that I can get at the feed store. (Stall Dry is DE + clay which might be safer in this form than powdered DE.)