I needed a weather proof tile effect for a dollshouse I was building in the garden . I stumbled uphe MINACO roof tile mould by chance on EBay - It says to use casting powder but I just used cement in varying mixes (2/1 , 3/2 , 3/3 or just by eye ) . I cast the tiles some were very fragile and some were hard as stone , stuck them onto my plywood roof with gorilla glue , and gave them a good coat of varnish - love the effect