Covers over sandpits ensure play areas are kept hygenic  by eliminating animal soil and leaves.  We typically manufacture from light weight mesh so the rain can go through also allowing it to breathe.  Our usual method is to put chain around the outside edges to give the cover some weight but so that it is not too heavy to push back.  We often attach at the rear through awning track or we can use side release buckles and webbing in order to tie the cover up without lifting it to get it out of the way for the children.