We taped levels to long 2 x 4's to verify that the corners of the house stayed somewhere close to vertical. If the walls get crooked, it's easy to bash the bales back into place, but if the corners get crooked, it's impossible. Either the bales have to be retied, or the corner has to get pulled apart and restacked. The black stuff over the first course of bales is tar paper. It's a county code to keep rain from splashing onto the lower bales, but of course, also impossible to apply earthen plasters over. Since we had a porch and stemwall, we later received county approval to remove this paper.