Check on www.johnbridge.com for help on tiling. They have a lot of people with experience in heated tile floors. There are a couple of methods...matts, or wires. It's a little less expensive to use the wires because it means you do more of the labor in laying things out. this also gives you a little more flexibility, but if you have the custom matts made and you decide to change things or measure wrong, it can be a big pain.