Why did you want to relay these stone?

Why wouldn't I? They're awesome stones. Most likely won't buckle much when the ground freezes this winter either. Rather have a nice solid patio than lay some cheap thin stone. Wish we didn't have to take it up in the first place, but had to in order to install a new outdoor furnace.

Typical poly sand is for joints less than a half inch. There are specialty ones for joints up to 4", but you need to read the bag to ensure that's what you have. If your joints are over 4", the poly sand may not work for you

I think that was the point of Ink's question, why did you need to take them up. Got answered.

Leveling uneven stones is tough. No easy answers from me - I've laid uneven paving slabs and it was up/down/up/down. Propping them up to the right level and pushing sand under them might work if you can get in sideways.

Speaking of gaps, I happened to see a patio yesterday (made with much smaller stones) that was somewhat spoiled by wide gaps - it is worth the time to lay it so the gaps are as narrow as possible, and follow other rules such as trying not to have long through-going gaps. Hard to play around with stones that big, maybe make paper mock-ups from a photo and do the puzzle in paper first? Maybe there's a trick that professionals use to do that.

Karin L

I think you'll find the way most pros (or talented amateurs) deal with stone is some sort of intuition. When I was building stone walls it was just look at the hole, walk to the pile, pick up the piece that said "pick me!" and set it in place. Probably not the answer you were hoping for, but there it is

You're still going to experience some heaving due to freeze and thaw but the thickess of the stone is going to limit the amount much more than if it was a standard 1 to 2 inch thick pc. of stone.

I'd still install a class II base of about 2 inches min. if you have highly organic decomposing soil ( as opposed to bedrock or decomposed granite base ) and then use sand as your leveling agent.

If the stones vary a lot in size / thickness . you can use the class II -( get the smaller 1/2 inch vs the 3/4 inch road base ) as an assistanted leveling medium.

are you talking about stone that is about this size ? - 3 to 6 inches thick :
{{gwi:37121}}From portfolioMay08.jpg
{{gwi:6403}}From portfolioMay08.jpg

Yeah, the stones are about that thick. The ground beneath the patio is pretty hard packed clay. We have started with a base of stone, then manufactured sand which is coarse, we're laying the biggest stones first and filling in with the smaller ones. We're just sort of picking stones as they fit so far and continuing to level as we go.

I think we will be filling the joints in with concrete, but now sure how to do that yet? Cross that bridge when we get to it I guess.

diannelmt,
I wouldn't suggest using concrete to back fill your joints with.
It will adhere to the sides of the stone but because your sub base is clay and clay tends to expand and contract the concrete will eventually crack and start pulling aways from the stones.
It may take some time to do what I described above due to the thickness of some of your stones but it will occur and it will happen even faster if you are not using a uniform thickness of stone.

You might consider using a very fine mixture of small chipped stone and fines/ stone dust . this will bind well and will flex with the stone and won't 'chunk out' in the future like the concrete will.
Simply retamp it back down and wet it to settle it back into the gap of the stone.

I've used the method described by Marcinde - it involved a lot of adjusting, turning, lifting, adding sand under this corner and that, jumping on rocks to make them settle, and my rocks were smaller than yours! When we couldn't find one that fit perfectly, we'd cut the stone to fit. It was helpful to have a piece of old wallpaper, to measure the shape of slabs and compare to the shape needed. As you see I'm not a pro...