Scootter

I have my plans together for some cages I'm going to build out of melamine. I was watching YouTube and saw a guy put heat tape inside the cages, on the floor, on the hot side. He covered it with ceramic floor tiles and sealed it with caulk to make it water proof. I seem to remember that you shouldn't sandwich heat tape next to wood because there could be a fire hazard. I also think I remember discoloration on the outside of my last melamine cages where the heat tap was. Am I miss remembering? It seems like even with a good thermostat there would still be a big risk of combustion.