The cages will be made out of plywood or melamine... the heat mat goes inside the cage and then you put a piece of vinyle flooring over the top so it wont have to run the flex watt too high preventing any burns/fires. I bought the cage plans online and it gives you step by step instructions how to build them... for 30$ I think it was worth the money bc the finished product is simply awesome... I'm just new to the flex watts and how much I'm going to need... Im thinking like 1 1/2ft of the 11inch stuff will work?