I can't seem to find the answer to my question. Maybe someone here can help. I have my frame built and ready to anchor it to ground. I've read varying ways for building the foundation. I have 6 large concrete circles that I was planning on anchoring the frame to. However that would mean allowing the steel frame bottom to come in contact with the earth/dirt. After some thought we think this isn't such a good idea. We're thinking it won't be long before that cheap steel will rust. So should I go ahead and build a wooden frame for the bottom? Hope this makes sense.