I've seen it done from a distance - the larger stones are cast randomly first, followed in size to the smallest ones.
I've done it with crushed seashells and pressed gently into place with a flat board with a handle. Pressing too hard will bury the product - defeating the purpose.
PRACTICE on similar material first is always a good measure. (assuming you are going to use the preferred stucco protocols ??).
The expansion joint may be a preferred method for different parts of the country.

 

Thanks for the tip on the largest first. I'd have to make some kind of sieve to catch them. Chicken wire? The supplier would send a ton bag of various sizes. I've never done stucco but have done some interior plastering. Will have to read up on it. That's the plan.

 

The supplier would send a ton bag of various sizes.

a TON? do you have plans for the rest of the rock? I'm just guessing out loud here that you would only need 10-15 gallons of rock for one 4x8 panel. How many panels do you think you will do ?

 

The densely packed stone are a precast panel I have done many pebble & shell Stucco textures & there is NO way to get a dense pack by hand applying Stone.
You can check with the local rental store to see if they have a Shell Gun, it will handle the smaller stones.

 

So you can buy those panels ready-made and "hang" them on a building frame? Some kind of cleat system?

 

I assumed about 3 pounds of stone per sq ft, let's say 90 pounds per panel. And I'd need enough for 15 panels, so about 1300 pounds, give or take. But I'm just guessing the lbs/sq ft.

 

I've seen a process to get this look by pouring exposed aggregate concrete for a retaining wall. Pull the form off and spray away the outer edge of the concrete, leaving the gravel exposed. It looked great after it was all sealed. That process might not be practical in this situation, but it did look wonderful.

 

It is called Do it Yourself: Artistic Craftsmanship. Don't dampen the guy's spirits with alternatives without letting him at least try the process.
After a 4x4 sheet of practice, I would like to see the results.
And, since the topic of "ready-to-hang" panels is on the table, making your own panels in the horizontal position will be 100 times easier than vertical, if you have that option.
Of course, working out the cleat system and dry-fitting all the panels in place before fabrication would be a good idea. (and, figuring out the weights and weight supporting systems is pretty important).

 

I didn't respond in an attempt to "dampen his spirits"... I simply gave another option if the OP or if someone else see's this thread and has interest in this process.

 

The trouble with pebble dash is that the pebbles start falling off after a few years. It's also difficult to match when making a repair. Used to be really popular on 1930's houses.