New 4x2x4 Carpet enclosure in the works! We're using PureBond Maple plywood panels and knotty alder for the frame and trim. The floor is insulated and it has a false ceiling as well. I will be welding and fitting a black polypropylene liner for the enclosure on Monday. The sliding glass doors will be installed Tuesday. Lighting and heat emitters come after that.
*I'm hoping the 1/8" black polypropylene liner will help with husbandry, cleanliness, and to protect the wood from moisture. The poly will cover the inside of the enclosure except the ceiling. It is 100% watertight.
This is what the welded plastic looks like (except this is clear). It's a thermal weld using hot air and polypro weld bead: