Join Date: Jan 2012
Location: Plattsmouth, NE
I would be concerned that the adhesive and vinyl would outgas something toxic. I wouldn't personally risk it at all.
Also, I think the point of using tile is so you can remove the tile to clean it.
You should not use an undertank heat mat without a controlling device. It will not keep a stable temperature, and it WILL overheat sooner or later, and may burn your animals. A thermostat is best, but a rheostat will do if your home temps are stable.