2ft x 2 ft Polymax kennel flooring makes a perfect base for spreading dung. Should last forever. Comes with 2 pieces of fiberglass window screen.
Polymax support panels can be ordered from FarmTek Supply, 800-327-6835. Order STK # HA2215. The panels are 2 ft x 4 ft . Use fiberglass window screen placed loosely on top of the panels before placing thickness grid.