I've been buying racks for my firewood and my father in law made a couple wood racks out of cinder blocks and landscape timbers. He stacked the ends in a criss cross pattern and then the middle was just stacked regularly. My question is how level should this type of rack be? I'm making one for my house and my yard slopes down and right now I've got it where its about 2" off. The lower side is about 2" off according to the level. I was thinking about digging out if I can since its close to a tree to make it more level. Do you think it needs to be perfect or does it need to slope a little?