You will get little to no heat transfer through 5/8" melamine. You can use a Kane matt, or my choice is to use the Flexwatt or other brand of UTH and cut a 1/8" piece of plexiglass or plate glass 2" bigger in W and L and silicone all around the edges with good adhesive caulk and you are now good to go. I do the same thing with my Proline cages. The Kane Matts are real thick, yes they a real nice quality but I prefer having the heat on the inside as I can directly control the heat without variations in heat transfer. Works for me.