I used the extra rack from my oven for weight while still allowing air flow and light to get through, it's easy to lift off and replace also on small areas.Oh, Ron, it does have a cover. I zip tied chicken wire all across the top, a hen could jump on it and not fall through. The problem is I left a little space where I can pull it back to access their food and water, and it keeps leaving a small space where they can escape. I need to fix it tomorrow so it stays down but can still be opened. Not sure how I'll do it but I'll figure something out
Speaking of chickens being good fliers...I accidentally locked them out of the coop one night and found my Splash Andalusian 12 feet up in a tree!