I still have some kinks to work out and some money to save before I start building a cage for my Veiled, but this is how I plan to utilize a drainage system:
I will be using Melamine Whiteboard.
Melamine board isnt waterproof...... Moisture will very quickly soak thru to the particle board. You need something solid like Corion, plastic or even plexi glass.
Yeah, I forgot to mention that I was planning on adhering plexiglass to everywhere the soil was going to be: bottom, back and both sides about 14" up. All the creases will be sealed by either aquarium silicon or a non toxic caulking glue. After many thoughts of going back and forth I think I have decided to go with a screen front, and just ditch the other idea(s) I had. This will help from creating a humid box and helping the cage to dry out quicker and will be a lot simpler than the other idea I had in mind. The back and both sides will be vented in some way around the top through either large vents, like used in houses/campers, or aluminum black screen, or maybe even several circular vents.