I have read through Metalshaper's thread, he is very talented! I reread his thread last night and it sounds like he is using 16 gauge for new body he is building. I think I'll try 16g for the floor. I probably won't get the raised ribs close to 1/4" deep but hopefully it will be rigid enough using that thick of material.
Yes I’m using 16 ha cold rolled. I can’t get any real depth even with my heavy duty bead roller. The machine I use is a pullmax and that is the only way to get them deep like that without stretching it so much that it’s thin enough to split.