I built a dual rock sided extension on my house, unfortunately a divorce removed me from the home before I could appreciate the qualities of having tons of rock on a east-south and west wall of a lower level on a two story home. What I do recall was stone is freakin awesome.
We employed sandstone found on our property here in northern New Mexico.
Although it is interesting how y'all describe working with river rock, I would not have figured that out, I just thought it was impossible or at least too hard for the effect.
Our family is super lucky obviously to own a couple hundred acres in the mountains, we have a large selection of rock, and a great variety is as important, as a great quantity.
We always hunted for rocks with at least two qualities, two flat edges, at right angles to the front. We chose sandstone because it holds up very well to weather and it is easily trimable with a hammer and coal chisel .
Limestone we have everywhere, but it is brittle and cracks when it gets wet and freezes, Granite is gorgeous, but we are at 7500 feet and not very much is down here, plus it is literally too hard to work with.
I believe I invented the technique I employed for our double-sided rock wall system, probably not, but I never saw this done so I might as well have.
I like big rocks, which might account for my sciatica, but big rock cover great areas, quick, with hardly any mortar.
Like I said, find lots of rocks with at least one, preferably two right angles, and find a way to stand the rock up on the previous layer or foundation.
I can't think of anything more interesting than fitting rocks together like this. It is so primal, very satisfying.
It takes time, there is no rushing, which I didn't mind when I was young and strong, I had a few buddies helping collect rock, and yes a huge selection it what makes finding the proper rock for each instance work.
I was able on the lower rows to stand 200 pound moss-rock as they are called around here back to back, with a small space between them. After several rocks were in place I wadded newspaper into the spaces between the rocks, laid in any EMT (electrical conduit) and crap loads of rebar, then started mixing concrete with an old cement mixer.
On the lower layers it was easy to pour concrete from the wheelbarrow between the rocks, the bits of newspaper worked surprisingly well at keeping the concrete in, and with moss-rock it is critical to keep the concrete off the lichen, or it will kill it, yes is a living wall, still is as far as I can tell, I drive past it every day, I never did get around to mortaring the rock, the technique with the newspaper worked well enough that there was really little need, sure there were a few cavities, and if I still lived there I would have done it. Life changes, what are ya gunna do?
In places where the rocks were not balanced well enough to stay in place while buckets of concrete were poured in, we tied the two sides together with metal bailing wire. We got that wall up to eight or nine feet high with this technique, and it sure is pretty, I don't miss the woman at all, the wall however is truly missed, every one ought to build one rock wall, just place it where it doesn't matter so much that it is a heat sink.
And lastly when moving wheelbarrows full of wet concrete to heights of eight feet, one learns how to build sturdy scaffolding out of very large timbers, with ramps wide enough to keep cherished buddies safe and secure, after being a rock fitter is only one part of rock work
My next rock wall, if this sciatica goes away, will be behind glass, a green room on the south side of the house, then an interior rock wall, interspersed with more glass, so the sun can shine on the rock in the Winter, rock still has a place in the DIY builder's toolbox, sure it can be modernised,
for instance I thought about timber-frame with SIPS and rock facing
Anyway you do rock, have fun