Here, An Example for you. The cubical , generally waterproof to 1.8 meter height including the flooring as well. Just like a fish pond. If you look carefully the flooring is recess. That piece of wood on the floor is 2 x 2. I haven't gone to that DIY topic to write just yet.
What I can tell you is that my portfolio is huge. Currently on The Culinary Classes for beginner.
Here, is a photo for you to look at #howto