How do I build a shelf near cinder block & wood? I am needing to store some organization files at a storage facility....

I am needing to store some organization files at a storage facility. I need a opening to build some inexpensive shelfing. I can not hammer anything into the metal so it have to be free-standing. I think I hear somewhere that you could use blocks and wood to do this. Is that true? The unit is 10X15, separated by 5 ft spacing metal post.
How do I insulate a log burning chimney...
Answers:    Yeah, you can do it. Just don't jump too high next to it...Get some cinder blocks and some 1" by 12" boards cut to length. Lay a couple of blocks on the floor following that with a shelf lay across the blocks. Next put 2 more blocks on top of that followed again by the shelf. So on...don't go and get too high near this though. 5 ft. is the max. I've done one. It was ok, but still bothered me. That's alot of immensity to get whacked beside.
Attic insulation?
cinder block under respectively end of board, repeat for subsequent layer.
If board is long (6 to 8') inevitability cinder blocks in middle layer for support.