I agree that the main room should be considered first. Maybe I'll lay the pattern out through most of the area to be sure. Also it's a concrete slab that I have so I assumed that I didn't need an underlay. Am I wrong?
I'm going to tile my house and going to use 20" and 6" tile pattern. With this pattern, do I need to start in a specific place, or can I start in the bathroom and work my way down the hall through the kitchen and dining rooms?