What can i use for a portable shooting surface?

I live right behind a tennis court, and I would like to take some hockey shots there with pucks and my ice hockey stick, but I don't want to wear down my blade on the concrete. I've looked for shooting tarps in stores, but they get really pricey. Is there anything else I can use in place of the shooting tarp which is sold in stores? Also, where could i get it from (I live in Toronto, Ontario)? Thanks.