25 years ago I had to choose between stone dust and sand when laying a brick patio using standard sized bricks. The underlying ground here in Virginia is fairly high content clay, I can absolutely state that stone dust is the way to go.... here are a few pointers; 1. Use a rigid but moderately flexible edge guard to define the area. I used aluminum about 4 inches tall. Don's use something softer like plastic or nylon as it will flex and your bricks will start to migrate all over the place no matter whether you use sand or stone dust. 2 . Use 4 inches of stone dust, but apply 2 inches first...then compact it with a manual or mechanical tamper....then thoroughly soak with water and wait a couple of days before applying the 2nd layer of stone dust and tamping and watering again. (BTW, I really don't understand the comments about stone dust not draining well....you will see the water soak quickly through the stone dust.) 3. Make the area as level as possible using a screed (look it up :) 4. Install some water permeable landscaping membrane on a fairly well leveled area. This will promote drainage and stop weeds from infiltrating from below. I will also make it easier to slide the bricks into place. 5. Install the brick. Either full size bricks or the thinner pavers. I used full size bricks which are more stable. To ensure that the bricks are level with one another, place a piece of piece of wood (approx 3" x 8" by 3/4" ) across the surfaces of the brick you are working on and its adjoining bricks...then hammer it with a large mallet until they all the bricks are even. Give then some good wacks...full-sized bricks can take it so long as you use wood as a buffer. Be gentler with the thinner pavers. 6. Depending upon your personal preference, you can butt the bricks directly up against one another or place a think spacer between them. I use pieces of asphalt roofing shingles to maintain uniform spacing. I like the look and using spacers allowed me to adjust the alignment for bricks which may not be uniform size. 7. Regardless of which way you go on item 6, sweep stone dust into the joints between the bricks. Wet the area, let it dry and repeat again. The irregular shapes of the stone dust will lock the bricks into position much better than sand, which is more round. Sand will not get into some of the smaller joints between bricks. 28 years later I am still VERY happy with my results. Occasionally a nearby tree root will distort things a bit but that will happen with either sand or stone dust. I just remove a few bricks and cut out the root. The only periodic maintenance I need to do is sweep new stone dust in the spaces between the bricks one ever 4-5 years. Good luck.

Oh, how I wanted my natural bluestone patio...well, it now looks anything but "natural." It's a hot mess! Original landscaper installed and used polymeric sand because that was "best." He recommended not sealing it. Or, as he said, "Let it sit a year and then seal it if you want to." Very shortly after installation, stones started turning orange or had deep orange/rusty spots developing like a rash. The polymeric sand grout started popping up like worms after a rainstorm by year two. Hired a new hardscaping/landscaping company who--at year three of the patio--power washed it, swapped a few stones and tried to remove some stains, installed a new type of polymeric sand (which is supposedly better for the larger gaps the earlier landscaper used), and sealed it. First, the power washing did leave what looked like swirls of gray "graffiti" on some areas, but that seemed to go away with sealing. Until it rained, I wasn't sure they had yet sealed it, but it was evident when water beaded up and remained on the surface. After it dried, white patches appeared all over the stones. Reading how this can also occur with sealing concrete pavers, I'm now wondering if that composite deck idea was better! All I wanted was a beautiful, natural bluestone patio. I've stepped on countless university and college walkways that do not have these issues, and that is the look I was going for. How do they achieve such beautiful patios and walkways without the issues we homeowners face? I know they don't use polymeric sand and their "deep pockets" must be able to afford the best stone and best installers.

" ... then take a four foot line level with a square one inch block on the end for the pitch reference." Hmmmm..... I didn't get that at all! I would use the string/line level for excavation .... as a guide for creating a reasonably accurate excavated pit. The pit should be a few inches larger beyond the limits of the finished patio. Tamp the sub base to the desired elevation. The edge of a straight 2x4 could help you determine that the surface is in plane. Set it on the soil, as if you were screeding, and in that process, verify if there are any depressions. Screed in one direction, and go over the whole thing again in a perpendicular direction. And you'll end up with a reasonably in plane surface. Tamp and double check the pitch and also that all depressions are filled. Once it is like a hard floor and at the correct level, install the Brock base. 3/4" PVC pipes -- two of them -- are commonly laid parallel on a tamped base (in this case Brock base) as a guide to screed sand to a 1" thickness, using a 2x4 as a screed board. Since this patio is only 8' x 8', you might could screed nearly the whole thing in one pass. It might be easier, though, if you screed out a 4' width pass, and then move one pipe pole and screed out a second pass for the other half of the patio. The retaining edge will set on the screeded sand base.

This thread devolved just as quickly as someone didn't want to hear the truth. For a bystander to jump in and call the truth-teller a jackass added fuel to the fire. And then wacokid misinterprets who the recipient of the name-calling is, as it was not the OP. When someone says, "Any help would be greatly appreciated," one would think they're open to hearing anything that helps ... even if it is not 100% a direct answer to their initial question. Sometimes help hurts, but it's only temporary. If it's paid attention to and ends up where something gets fixed, it's "constructive criticism." Gardengal's observations are the same ones that came to my mind within 3 seconds of looking at the picture. Why would someone want to repeat the errors that a previous homeowner made, just because that's what they did? ... especially when it's so EASILY fixed?? Doing that does not make sense to me. I'm pretty sure that however the walk was tamped was not with a steel tamper -- the tool made for the job. So the walk would not be as compressed as it should be. The easy way out is to let it settle over some time (for a few months or as long as one can tolerate it), pull up the blocks, add more sand and reset the blocks, tamping them in again. But wouldn't it be better to fix the layout and at least make it functional? Move the walk over, widen it and fill in the wedge next to the curved walk with a little concrete. (A walk this small would be just as easy to make of 4" nominal thickness solid concrete for more durability.)