We have a fire pit that is super long and sits right under a tree, so we want to have a lid made that will prevent the leaves from constantly falling into the lava rocks. I was thinking a metal lid like the one pictured would be the best solution, but is there a way to prevent it from rusting and then the rust bleeding onto the concrete pit? Or maybe a better way to design the lid in general? We live in Southern California, so not dealing with super cold temperatures or ice, just rain and those falling leaves.