I am going to build a small single shelf rack with room for just 4 shoebox size containers. It will be housing cornsnake hatchlings so I need the warm end to be around 85 degrees. Assuming that my room stays around 68 degrees during the winter can I get enough heat using a strip of heat tape for belly heat? I know that if I put a heat pad under an aquarium I don't get enough heat because the ambient temp of the room is too low, but I'm wondering if an enclosed rack will have the same problem. If the belly heat alone wouldn't do it, would adding back heat work? I'm also wondering if I can have the boxes sitting on the heat tape or if it is necessary to provide a channel. I plan on using a 1/2 or 3/4 plywood.

-----
Darin
1.0 Red Tail
0.1 Basset Hound
0.1 Mutt Cat
1.4 Children
0.1 Wife