Heat tape on wood vs. melamine?

[Thrush]

Say, theoretically, if I build a rack for my tortoises out of wood or melamine, I want to know if there's a difference in the heat that has to be out by heat tape to heat the internal cage temp to the same temp.

so basically, I'm asking if there's a difference in the insulating ability between melamine and wood. (say pine board)

I'm designing a display style rack for three cages stacked for Torties.
Probably with dimensions of about 5' x 2 1/2' x 14" high but I've never used heat tape before, and right now I just have the pet store variety of undertank heaters.