Just finished building my first turtle topper basking area and im wondering how to go about sealing it, I want it to be safe but at the same point not rot from any of the mositure.. its not fully finished yet I still need to attatch the ramp and finish the floor with fake grass. If anyone has any ideas about water proofing this box please let me know. Forgive me if this is the wrong area im new to these forum's

below is a picture so far of the project for my slider shredder.