I had a raised deck built several years ago and had approx. 1.5" stone poured under the deck and around the outside of the deck.
My problem is the stone is sent flying when ever the dogs run on it. I would like to anchor the stone in certain areas to prevent this. Foot traffic is all that goes on it.

I have watched several YouTube videos about dry pouring concrete and thought this might be a good solution for those problem areas.
My question is should I use regular concrete bags or should I use a Mortar mix since I already have stone down. The existing stone is about 4" deep.
I thought what ever I decide on could be raked into the stone base.

When you mention dry pour, it sounds like you want to pour the dry mix then spray water on top?

If so, i did something similar under the recommendation and guidance of a neighbor. He said to use Quickrete. Trick was enough water without washing the mix away.

I did my project to fill gaps between stepping stones.

This is exactly what I plan to do.
Thanks for your input.

Stepping stones are used by any all who come to the house. Oh, stepping stones are red, previously used brick.

Been here 22 years and did the dry pour when i first moved in. Only now is some of the pour cracking, it is / was that flexible.

Oh, make sure to sweep up excess dry mix before spraying - and don’t the moistened mix splash where you do not want it (though in your case, that doesn’t sound like too much of an issue)

Stone in concrete bags is smaller than the 1.5" you have laid so I'm afraid your stone will be too large if you try to mix it with mortar mix. I would use the bags. Take this with a grain of salt as it has been many years since I've worked with concrete.

They also make a binder product which is to be used with gravel. For example, we have a large-stone walkway that we installed last year where we continue to have wash out of the gravel in between. They’ve used some of this product mixed in with the gravel to good effect, and we’re probably going to use more.

Cement/concrete is weakened when mixed with too much water. I would be afraid that overdressing with a standard mix might end up as dust. If there is a product that is designed for such a use, maybe different. I would look for something that has and additive that is intended to allow flexing, etc.

Is your stone round (creek run gravel) or crushed aggregate (sharp/jagged). Rounded stone is intended for drainage and not worth a darn for anything else other than ornamental use.

You can use the method you spoke of, but as an engineer to has put down a few thousand miles of pavement it makes me cringe inside. Concrete regardless of how it is installed, needs proper joints because it WILL crack and you need to control where those cracks propagate.

I'd saturate the ground where you are going to put your bag mix down. You don't want standing water, but want the ground throughly wet so it can wick the moisture out of it. For the surface, I'd mist it very gently as cement dust is stupid fine like baby powder and will get everywhere you may not want it.

Good Luck!

There are MANY dry pour vids on youtube.

It seems the actual ones testing it all admit it is junk.
You might look at a few.

One of the YouTubers I follow just did an update on a couple ~2 year old dry pour projects. Spoiler alert: it didn't age well.

There is a product you can buy that is made for what you want to do . It's a clear liquid . One of them I found is called Easihold . A jug covers 80 square feet .

Its crushed aggregate that's down now.
I will check out Easihold.
Back to the original question, Concrete mix or Mortar mix?