I'm planning on pouring a concrete pad that'll be about 10' x 16'. It's going to be situated under a deck, and it'll be used for storage and a carport. There is a slope of about 12" to 15" in the 10' direction while it's basically level in the other direction. The pad will be about a 18" away from the edge of the house, and won't abut anything. I've done a couple of smaller pads (3' x 3' and 3.5' x 8'), so I think I can manage the finishing and all of that. But I do have a few questions, and I've found a lot of conflicting advice online, so I was hoping somebody could help out. Here are my questions:
1) Ideally, how thick should this pad be? I don't mind spending more on concrete if it actually serves a purpose.
2) Is it necessary to have expansion joints?
3) Is there anything special that could be done to make it more stable when the ground shakes? I was thinking of digging a few footings/piers, say, 2 feet deep, since it seems to me that these would help it stay in place, and it's not much extra work.
4) Anything else?