After many months of research and deliberation over countless track plans, I'm finally ready to get started on my layout. Please...hold your applause until the end. I find myself feeling like a newbie again, because I'm not sure what materials to use for my layout. I'm building a 3x6.5 ft layout (roughly door sized) with grid 1x construction. Now for a few questions: 1) I assume I should use plywood. What thickness do you recommend? 1/2" or 3/4"? Other? It's important that this layout be mobile, so weight is definitely a factor. 2) Should I screw the grid to the plywood or just nail it? The reason I ask is because I'm likely going to build shelving/storage, and the layout will rest on top of them. The opposite end will be supported by two legs, and I hope to build a rolling toolchest that will wheel out from underneath. I'm concerned about the overall strength of the unit. 3) Given what you've read above, I hope I've given a general idea of what I'm hoping to do. Think of a computer desk, and you're on the right track (no pun intended). I even want to make a slide out tray, where most people have their keyboard, and use that for my controls.