How many yards of concrete to pour a 12x12 slab 6" thick for a hottub. I've only done two and they were 8x8 and used bags, and i know that was probably more expensive. Anyone in NJ tell me how much they would charge for this, how much a yard($100?), how much for delivery? How long do I get the truck for? I will only need to move the concrete about 30 feet. Thanks for all the information.