I made grave site stone covers from small scraps.
http://www.halloweenforum.com/halloween-props/128886-faux-rocks-over-grave-scrap-foam.html
http://www.halloweenforum.com/halloween-props/128886-faux-rocks-over-grave-scrap-foam.html

after all zombies will burn ... now to start on my flame thrower ... zombie apocalypse is just around the cornerDissolve it into a bucket of gasoline until you have the consistency of heavy syrup. Congrats you have made napalm. One can never have too much on hand ;-)