What about drainage. I mean, the center of the spiral will be at least 5' deep by... um How wide is each section exclusive of the brick? Seems like you would want to fill with a little crushed rock or something at the bottom as you go up the spiral if for no other reason than to save on soil. I guess I am still mulling over the one I saw in Gaia's Garden that showed just sort of rounded rock. But after you experience, it would seem like they would just sort of splat out and the spiral would sink like a big pancake. Perplexing
