Thank you, Jay, Jeff, Rubin, Bill, George!
Jeff, I'm glad to hear from you! What's it been, 2 or 3 years since I visited you and your layout? I hope you are well.
George, yes with a layout the size of yours, I would have approached it the same way. I would do the layout in sections.
Great discussion everyone! Thank you for participating. Yes, the floor is important, and more important the older we get. I agree with George, the carpet would always be a mess while building the layout. Something else would be good. Bill, I have looked at the anti-fatigue mats myself. I may buy a few for the operating area once I'm not rolling around on the stool. This house we are in was my wife's grandparents, and later parents when Grandma passed on. Once Kim's dad passed on, her mum wanted out and talked us into buying it for a sweetheart deal. That was just over 10 years ago. While her parents were living here they had some remodeling done. They had ceramic tile put in the laundry room and master bathroom. The train room was an addition built only to support he sunroom above. They only intended it for storage. The builder talked her into letting him leave a bunch of ceramic tile for this room; odds and ends from other jobs. My wife wanted me to put down the ceramic tile, but I knew that would make bumps for rolling around. During the summer a year ago, I dragged all the tile out of the shed, scrubbed them up from 10 years of who knows what in the shed and discovered what a mix match he had left. I also realized there were several different sizes. I counted 4 different sizes from 11" to 12 1/2 inches. There aren't even quite enough to finish the room even if they were all the same size. So I showed my wife; in my opinion he just dumped his refuse on Mum and Dad. I have them stacked under the layout, and should have carried them down and dumped them at my dad's house when we had someone in to clean out all the old junk. Maybe the ceramic tiles will be passed on whenever we leave this house.
All that to say, while it isn't pretty, the concrete floor allows me to roll around easily, and the shop vac works great. My wife bought me a very firm cushion that helps my damaged sciatic nerve when sitting on a hard chair. Since I can only kneel on one knee, and then for a short time, it works better on the floor than my strap on knee pads. I worked on my knees way too much over the years, that is for sure. I should have taken note to the trouble my brother-in-law's uncle had with his knees. He was a carpet layer.