The problem with my cold frame was mostly that the center front wooden support rotted and the weight of the snow crushed it. Once it was gone, the side bowed out and then the covers sunk in. I propped up the covers and used string to pull in the sides. Once my husband saw this, he got out tools and fresh wood and fixed it properly. Now it has a reinforced center post, reinforced sides and a brace running across the middle of the frame.