Re: Building a large spire out of blocks of eggcrate, what to do about the sides?
It looks very "high-rise" right now. If you want to clad it in natural materials, but not all GS and coco, you could try cladding some of it in slate. I have been using slate in a couple of builds for a natural rock look. Nothing looks more like rock than rock. If you get a rock chisel you can split it vertically into very thin sheets. This gives the same look as a slab but with a lot less weight. It can also be cut easily with a wet tile saw, which you can rent from Home Depot or some other DIY store.
There are lots of threads on how to make a rock texture, and those techniques are also an option.
If you want to go more organic on your structure- GS foam and carving would be the way to add curvature to your form. Cladding with Cork Bark is an option as well. You can do all of the above!
"Rock On" as they say, keep us posted.
There's Bears in these here Woods. Wouldn't have it any other way.