I got two racks, boards and glue and will be putting it together tomorrow. I'm thinking about running the flexwatt or heat pad on the shelf then adding another piece of bathroom paneling (cut to the same size as the pieces that are glued to the bottoms of the shelves) on top of the flexwatt so the tubs aren't sitting directly on the heat tape. Anyway, how are you keeping your flexwatt in place? Did you use aluminum tape or a glue???