I'm planning on building a 3'x3'x4' and I've got a lot of questions. (I'm really sorry if these are obvious or stupid I have only have the slightest clue what to do). First question- is plywood acceptable? Second question- how thick should it be? I was thinking half an inch but that seems somewhat thick. Third question- how do you waterproof? I was thinking about just using a shower lining and covering the wood with it. Forth question- would glass doors or mesh doors be better? Thanks.