Replying to What to use for rail/box?!

okay, so im looking to build a rail or box, i have built a bunch of boxes, and rails already for mybackyard setup with pvc pipe. The only problem that is happened is 1. doesnt stay on super well over time, 2. cracks when you land on it in cold weather. and 3. is a pain to put on/replace. So i am looking for other alternatives for the top of my rails/boxes. i heard one of my friends used that artificial wood stuff that they use for decking and benches thats like recycled shit, except idk how well that would slide with skis or snowboard. So does anyone know about the artificial wood stuff. or any other reccomendations besides pvc pipe, and metal. and stealing benches from my hs baseball fields..