This sounds wrong to me! I just finished a paver class today and have been researching our patio for the last few months.

Your supposed to excavate based on total height of everything. So 4-6 inches of base, 1 inch of sand, and then height of pavers - ~1/4 inch from compaction.

You put down base material, not fill dirt. Compact every 2 inches. They said 4-6 inches for patio, much more for a driveway.

Then you put your scree lines down (electrical tubes at 1inch).

Fill it with 1 inch of sand. Scree it out, remove the tubes, fill the wholes.

Make sure its all graded correctly and do not compact it.

Lay your pavers down.

Compact them.

Use your polymetric sand and brush it in. Then compact the pavers in again.

Then you blow it of and wet it to activate the polys and lock it all in place!

Maybe patio stone is different but who knows!

I don't have any experience machine compacting patio tiles of 18" size so can't comment on the pitfalls of using such large tiles. But for any brittle material of a given thickness, as it's surface area grows, so does the likelihood of its being broken. That's the first drawback of using a large patio stone. A smaller size patio stone shape--like 4" x 8"--would be more durable during handling and installation.

In theory, the process you propose seems reasonably sound except for one small detail. It's about impossible to achieve a compacted base that is uniformly in plane (or smoothly and uniformly warped if the conditions and plan call for it.) The compacted surface you're likely to get is one that's full of minor surface variations. There would be voids and high spots. I could expect that after the pavers placed on such a surface did their final settling at some future date, they'd be a little uneven. (This would be of greater likelihood with increased patio "stone" size.) Normally, as bibigblake suggests, pavers are compacted after being laid on an uncompacted, freshly screeded "sand" setting bed. The machine compaction gets rid of all the surface imperfections.

The 4" excavation sounds a little shallow. I would think that it would be that PLUS the thickness of your paver.

You wouldn't actually want the patio to be level. It should be designed to slope away from the house and toward the overall flow of drainage.

bigbigblake, where did you take a paver class?

Yard brings up a good point re: compaction. If you're using a paver from a quality paver manufacturer, the thickness is 2-5/8 or greater, AND the manufacturer's installation specs say to run a compacter over top - you're probably good to go. If not, set it in the bedding sand layer, hit it a few times with a rubber mallet to seat it, and move on. You may have some fine tuning to do down the road, but that's what you get when you choose those slabs.

No one has mentioned edge restraint. To keep your slabs from wandering off the edges over time you need to extend your base past the edge of where you want the patio and then spike edge restraint strips (google paver edge restraint) into the base with steel spikes.

A stone place here in Ft. Worth. They do summer classes and had brought out one of the General Managers of Pavestone to help give a class.