Yesterday, when I went to the yard to order my stone, gravel and sand, the lady tells me to not worry about the sand and just use the crushed, compressed gravel. She says something about sand being round and rolling while crushed gravel maintains its crystalline structure so won't move around as much resulting in less problems with the stones moving.

Anyway, I've been reading around a ton this morning and I can't find anyone who sets straight into gravel. Lots of people who do gravel then sand and even more that just do sand.

In addition, I dug my hole a bit too deep. It's about 7-10" deep (I was a little gung ho, I guess). I'm going to backfill a good deal of that with dirt so that the dirt is at least level with the bottom of my staked 2x6s.

Now, I've ordered about a 1.5 tons of the gravel which is going to give me about 3". My stones are 2" so that leaves me another 1" or so. Here are my options:

Backfill with more dirt and just use the gravel ordered.

Order more gravel and set in gravel

Get some sand. This has three sub-choices then. Do I just sent in 1" of sand on top of the gravel or is that not enough? Do I not backfill with as much dirt and leave room for more inches of sand inside the form? Do I reduce the gravel to 2" coverage and do 2" of sand?

Any feedback from those who might know a thing or two about a thing or two will be appreciated.

'Gravel' is a well graded, hard, durable, and natural sand and gravel, containing no organic (loamy) soils. It's free draining, which means water will readily pass through it. And it has a natural moisture content that lends to it's ability to be compacted to a very dense and hard consistency. Now, if that's what your dealing with, what does that mean to you?

It means that if what you excavated from the hole is more organic, loamy, or silty in nature, and not completely mineral soils (like gravel), then you need something else to use as a base, and dispose of that which you 'dug out'. If what you've purchased is similar to the description above, having no stones larger than an a half inch or so, then it will make an acceptable base for your patio. The caveat here is that whatever you use, it needs to be both free-draining, and it needs to be very well compacted, preferably using a vibratory plate compactor, so that when you walk on it, pretty much nothing moves.

Sand, by itself, as a base material, does not lend itself to deep compacted layers. Look at the stuff closely, and you will see that the particles are rather rounded in nature, and even thought the particles are small, they will react to compaction much like marbles, and ultimately they can move.

In the construction industry, gravel, while capable of being readily compacted to an acceptable base, isn't what the pros will lean towards due to the inclusion of stones up to and including an inch and a half or so, and they don't want to spend the time picking them out.

So, what does the industry use? More often than not, and depending on location, paver and bluestone bases are contructed of either crushed gravel, or crushed stone, or what is called crusher-run. Crushed gravel is natural gravel that has been 'processed' to eliminate stones that are too large by crushing them, and yet not requiring a sieve to pick them out of the material. Crushed stone is just that, a by-product of a quarrying operation that is crushed and then processed through a series of sieves to separate the particles by size, eliminating any and all fine particles, and creating uniformly graded products from 1/4" crushed stone up to 6" crushed stone. Crusher-run is another by-product of a quarrying operation, where stone is crushed and processed only to insure that no particle is larger than about one inch or so, with everything after the crushing operation left in the mix.

When crushed stone is used, it is on the smaller end, 1/2" or so. Beyond that, compaction isn't an option. Crushed gravel and crusher-run can be more densely compacted as the particles within are all pretty much angular, and will fill just about all available space within the layer when compacted by machine.

Sand and stone dust are used as a setting bed, no more than 1" to 2" thick, compacted, and then screeded to level. Bluestone, flagstone, or pavers are set on top of that. The dust and the sand can be worked by hand within the area of each stone in order to achieve a level final paver or stone surface.

In your case, if you already have the gravel, it's free of large stones, you can likely use it, compact it, and place a layer of sand or dust on top as the setting bed.

The keys really are....free-draining, free of large stones, and very well compacted. The material choice to fit that bill has a number of choices.