You'll likely have to cover some of the sides to keep up the humidity. I would also build a good drainage system into the bottom. Build the cage, then use a digital hygrometer to test it over a few days to see what levels you're getting. Generally a few mistings of one or two minutes a day is good for hydration purposes. If your cage is drying out too much between mistings, buy a shower curtain and attach it to one or two sides. Cover more or less until the proper humidity levels are reached. And remember the humidity should drop significantly between mistings, it shouldn't constantly be high. A low of 35% and a high of 75% relative humidity is what I try to maintain several times a day.
