Foil tape is fine. Now yes some has said the same about fully covering the flexwatt and fires and as there is no need to have to cover the tape entirely i wanted to try this experiment so i hooked up a piece of 11 inch flexwatt about 2 feet long and foil taped the entire thing and let it run full blast for 4 days just to see what happens. No fire. Temp never got above 118 degrees. Anyways i never attach the probe to the flexwatt. Some will argue this im sure but it makes no sence what so ever to hook the probe to the heat source and have to tinker and guess the heat in the tubs. Since the animals live in the tubs its common sence to put the probe in the tub over the hot side so ya know exactlly what your animal is getting. If this means having a dummy tub just for the probe then so be it. Or you can get creative and figure a way to attach it so it can be removed easily for tub cleaning. As far as particle board goes if your using tops on your tubs its ok. If not then the humidity will kill the particle board quick