Can drystacked block have a seat at this table?

I think a case could be made for different applications of this method, on a case by case basis.
One might scoff, and yes concrete anything has a lot of embedded energy, a polluting industry, on and on. But hear me out.

I can paint several scenarios where block in general might be a friend to homesteads... for a large basement it will save money, if you can lay block, or build a proper form, etc
If you build a tiny house that's not on wheels, working with stacked block properly can be part of your foundation plans, I saw one tiny that had about12 or 14 courses with waterproofing structural finish.  The wood walls were another10 feet up.  If you read more about dry method, it becomes apparent how little time it takes, even for a dumbass Georgia boy like me.  Mortar under first, or1st and 7th , courses. Then apply all the science by following all directions.... I hate those days when my three ton wall pins me to the floor.  

In brief, I wanted ask the community:  direct experience with existing structures and their age?
On a foundation or, less likely,  on rubble trench?      Infill with sand, mortar, fresh air, soil?
ALL OPINIONS welcomed, i know rammed earth is better for our earth but labor, form making, on and on mak3s it out of reach for me at the mo

Hey, this style isn't everyone's cup of tea,  but dry stacked made this look. That is the structural finish, one coat.  By a ery skilled laborer, not me.  

not for a structure wall, but I have used dry-stacked block on several occasions for sloped retention wall with very good results. I start at the base of the wall with a line of 6-inch blocks laid on level undisturbed soil end-to-end. Then I backfill on the up-slope side to the top of the first block line and compact the soil. Next, I place block perpendicular to the first line on top of each joint where two blocks of the first line meet. I can then place another line of blocks over the perpendicular blocks but set back (up-slope) from the first line by ten inches. After backfilling to the top of this line of blocks, the process repeats. As a result, the retaining wall has an average slope of rise = 24 inches /  run = 10 inches => 67 degrees (23 degrees from vertical). If the backfill soil is not well compacted, the blocks will tend to sag into the slope. But since they are dry-laid it is a simple matter to restack the wall  after a few years - much faster than the original construction. And although the slope is steep, the wall can be scaled on foot with care. This design uses the exact same amount of block as would be used for a flat vertical wall construction, but no footer and no drain holes required - every other row where the blocks are perpendicular to the wall face is an 8-inch tall x 10-inch wide exposed soil slope which is an excellent place to plant ground cover that can soon cover the exposed blocks and improve soil retention.

Soil compaction is a bit of an art. Elements of compaction to consider: 1) compacted soil must be free of organic matter (otherwise the organics will decompose and the soil won't be compacted anymore - it will settle) 2) compaction should be in "lifts" of no more than 12 inches - even a heavy duty mechanical compactor can't "reach" deep into the ground 3) soil should be slightly moist but no more than about 5% - certainly not muddy 4) if you want "instant" compaction, use clean gravel instead of soil and tamp it into place. 5) very clayey soils compact well and block water flow well, but once they become saturated they can flow. Don't use high clay soils for a critical retention wall design like I have described because softened clay can easily be extruded between the perpendicular-laid blocks in the lower part of the wall.

I've seen block buildings such as the picture you posted in many dry, hot countries.

I would absolutely want to use rebar, plus pouring in any available fill, and even then, not my first choice in my ecosystem - I consider the biggest danger to these buildings is earthquake, and I live in quake country.

Like any building method, location matters.  Areas where termites are a big problem, block buildings would be great!

Many modern "North American Stick built" buildings are only designed to live for 50 years. Any well designed house built to last longer than that (I've been told that "sealing" concrete can extend its life significantly as an example) is better than the status quo.

Sometimes "perfect" is the enemy of "better" - aim for better and hopefully, perfection can happen in the future.

Apologies to all, I asked:
'
In brief, I wanted to ask the community:  direct experience with existing structures and their age?'

Not the age of builder, rather "how has the structure aged over time?"
Thanks for a Puerto Rico perspective,  it seems y'all have major storms each year so the observations of soil type and appropriate block placement are very useful.  
Aside from stabilizing slopes, can others comment on shed/ greenhouse/ house efficacy?

Rico, are you asking in general, or do you have a place you want to build picked out?

Your bio says you're in N. Georgia, but permies are from all over, and giving us some idea what sort of land and climate you are planning for would be very helpful.  Building on sand is very different from building on clay or bedrock. I believe that South Georgia has a lot of sand, but I don't know how far north it goes.

I can't tell you much about using it but I can tell you one way of how NOT to use it.  Back in 1984 when my parents built this house they built the cistern with a dry stack concrete block.   It was held together with a yellowish trowel on material on both sides called Q Bond. (we did pour some of the cores in the block full for added strength but not all).  Cistern leak like a sieve.  Turns out Q bond isn't even slightly water proof.  Had to live with the fact for the first winter because we couldn't fix it in cold weather since we filled the cistern and started using it in Nov.  Next summer lined the inside with a trowel on stuff that looked like concrete called thoroseal.  Every few years when we cleaned the cistern did minor repairs.  By about year 20 the whole walls were buckling in.  Added a cross walled of poured concrete in to help and resealed everything.  Lasted about another 5 years and it is falling in again.  The concrete block had somehow rotted away, was literally crumbling such that you could break pieces with bare hands and the soil around the cistern is soaked creating a lot of in pressure.  Best guess is a combination of leakage, constantly varying water levels and efflorescence steadily destroyed the block and the changing stress from water in the soil did the rest.  I would NEVER use it to build a cistern and if I was using it for underground walls I would work on getting multiple layers of waterproofing between it and the dirt.  Plus I would pour all the cores full with rebar in each.

I built my house foundation in upstate New York nearly forty years ago with dry-stacked 8" block, cores filled with concrete and vertical rebar about 2' on center, bond beam at top, backfilled with bank run gravel and clayey soil. It is on a hillside, so two sides are full height block and two sides stick framed.
During backfilling after construction and surface bonding for water resistance, a pickup-sized dump truck full of gravel slid about 6' down the slope and hit the free end of a 25' section of wall (with a couple of one-block buttresses). I saw the wall displace 3 or 4" at the top, and when we pulled the truck off the wall after shoveling it all out, the wall sprang back to plumb with no visible damage. It has been sound ever since. The recent addition foundation I built has #3 rebar 2' o.c. each way and is nice and sturdy, backfilled before floor framing was built on it.

Keeping the courses level is important; in a couple of places I let a hump build up for a couple of courses, and it spread and magnified itself with every course thereafter until I shaved some blocks to bring the coursing back to level.

If you don't have bond beam blocks on hand, it is not hard to knock out enough of the top webs of a course to set rebar for bonding. It does not need a lot of concrete placed continuously around the rebar; the broken webs make good rebar chairs. A circular saw with a masonry blade can cut an inch or so deep to make it even easier to knock out rebar space.

It's good to hear tales of success and of woe.  I am not planning an immediate build here in Georgia,, but we are well above the coastal plain and the infamous Gnat Zone, where sandy soils make all building problematic.  I first pondered this style because of two outbuildings on our land.  They are oddities built in the 1950s, and I use the word "built " quite liberally here, perhaps "thrown together in haste" would be more on the mark.  

The first course of block might have been laid on our red clay soil , it's hard to say for certain.  
A super thin mortar of clay and sand was used.  It ap0ears to be 1 mm thick.  The efforts turn out almost like a dry stack, with later repairs, reinforcement by concrete gruel.  I have recently used Portland, sand and wood ash to keep them upright.  An odd cap was made to hold the chaos together, and heart pine was used, just like our 1920 house. Here is the tiny one, the other is 30 x 10 ft

As you can see, the rough sawn pine 2x4 s are more like 3x5, thank the Lord, and I fixed both roofs to keep them for a big project next year.

The modern dry stack is approved by inspection and by insurance companies, I am told.  This seems like a completely different animal.  From what seems to be a common description, the site
thenaturalhome.com
Posits the reliability of dry stack with waterproof hi tech Surface Bonding Cement, which is touted to make it stronger than conventional block walls.  Hence, I am trying to investigate a bit ......

"]Dry stack block with SBC was never the primary focus of our HTM design, simply an economical construction option for homeowner-builders. Other thermic wall building materials are functionally as effective: concrete, rammed earth, adobe, superadobe, and slag, stone, or bag walls. SBC is featured here given its ease of construction and better acceptance among engineers, building officials, mortgage brokers, and insurance companies. Engineering can be identical to mortar block walls common to commercial buildings, with SBC adding waterproofing and a great deal of torsional strength."

They demand that corners go up first, they are built up 8 courses, I think, and then the walls are raised , incremental and with string line and level.  I watched one video with a dozen members of a family dry stacking...... I was impressed at the speed, and at the end product. Inspector  approved, it turns out.

Thanks y'all,  and if anyone has warnings or encouragement on this specific , improved method,  please add comments.  I continue to learn, trying to keep going on a lifetime of learning.

Conrete block is the only widely available masonry unit in the US. Structural bricks, insulated blocks or aerated concrete blocks are rarity, expensive and available from only a few spots resulting in high transportation cost and minimum order quantities.
European houses built from concrete blocks in the 60s stand strong and nothing indicates they will not survive another 200 years. Walls are fire/insect/rodent proof, solid, quiet and easily reinforced to make them earthquake proof. CMU house can be built without any synthetics, as long as it's treated as a true masonry structure and not just a replacement for lumber to be covered with some wood furring, drywall, boards, caulking, etc. (also inviting pests to the created cavities). Because  of it, if interior walls are also block then entire interior can be beautifully plastered with lime or clay plasters. Interior masonry walls additionally brace the exterior walls making the structure stronger and reduce flammables to furniture only.
"Distance to combustibles" is not an issue, so building masonry heaters is easy and very compatible with the house.
Maintenance is low.

All of it makes it very permie in my opinion:
-wide availability (also of block factories) reducing transportation
-safe structure that will last a very long time with low or no maintenance
-easy to avoid chemicals as entire house can be naturally and easily finished with mineral materials

The main negative is the interior air quality, because concrete does not want to absorb moisture like adobe, cob, fired clay, porous stones or aerated concrete. It's easily visible when plastering. When we apply plaster to earth block, water is getting sucked quickly, making it difficult to finish it. On concrete it stays wet for quite a long time which makes plastering concrete much easier. I'm assuming that applying thick layer (at least 25 mm/1 inch) of natural breathable plaster would mitigate the air quality problem.

The second challange is how to inulate it naturally. Probably the best would be to build two wythe wall and fill the cavity with perlite, vermiculite or mineral wool. The other option, much more popular, is to attach rigid inulation to the outside and plaster it. Unfortunatelly it usually means using styrofoam which would:
-invite pests (mice love tunelling in styrofoam)
-add a lot of toxic material to the house, despite being hidden, in case of fire it will be nasty and if destroyed by pests, will need to be replaced generating more toxic refuse
Probably there are other rigid insulation panels, but mostly synthetic and if not synthetic then expensive, so the best would be the two wythe wall.

Dry stacked CMU would work the same as mortared provided it has vertical reinforcing. I use 0.5" rebar 32" OC. I'm mortaring and always build wallls at least 16" wide, which doubles the vertical bars.
If I did dry stacked wall I would opt for one bar per block, so 16" OC. I would also add a middle and top bond beam, but for most locations the top one would suffice.

Dry stacked block would be also the easiest building method as compared to other masonry techniques and even more easier than any wood structure construction.

I would not trust SBC as the way to reinforce the wall. I used it once on dry stacked paver wall and it cracked in excessive moisture. Also the SBC would be cement based, further deteriorating interior air quality.
Grouted vertical rebars, solid bond beam and natural breathing plasters would be a way to go.

when I had a contractor building a house in the Dominican Republic, I was surprised they did not butter the end of the blocks when laying the walls. You could see right through! The contractor said "of course not!" They rely on that gap to help anchor the stucco - known in most of latin america as Panneta. The panneta is made from sifted sand so pretty fine like pool filter sand, and portland cement - about 2 sand per 1 cement. They start with some that is too wet and sling that onto the wall with a cup. This moistens the wall and also supposedly gives the blocks more "teeth" to hold onto the panneta later when it is troweled on. After the panneta has had a couple of hours in place, they finish it by circular wiping with a large damp sponge to expose some sand and smooth out trowel marks. The finished thickness is about 1/2-inch.

Many good comments, and I am intrigued.  Thanks folks.  
Cristobal, you have a wealth of building experience,  so your word carries substantial weight. I thought the SBC was an integral part of dry stacking.....supposedly giving strength and waterproofing.  And I thought it was only exterior.  If you were building this wall, for example, how would you finish , interior and exterior? I have only used a OPC and fine sand finish exterior with some lime, on a looknormal block wall, then low voc latex paint inside.  

For surface bonded walls to be at all structural, they need to be coated on both sides. I have not depended on surface bonding for long-term use, just to stabilize walls before filling cores.

If filling cores, I would also bond first so that there are no concrete drips making the surface uneven.

Rico Loma wrote:Hey, this style isn't everyone's cup of tea,  but dry stacked made this look. That is the structural finish, one coat.  By a ery skilled laborer, not me.  

I love it!  Many people fill with foam or sand if used for a dwelling. I also like the hempcrete structures. They have very high insulation values.

I never built a large structure with dry stacked blocks. If I did I would use rebar plus grout 16" OC, so every block would be stabillized with one concrete core. This would give me freedom of plaster choice.
On the inside I would do lime and sand plaster, in two coats, to get around 20 mm/3/4" thickness.
On the outside - it would depend on climate, rain pattern, eaves size, building function. I can not tell if the water would be able to penetrate through the very thin gaps between the blocks. With my rain (slow that can last for 3 days non stop) , it probably would, as it wets everything that has some hardly visible holes in a tarp. In this case I would probably use some water proof plaster, but not necessarily SBC, because the wall would be already completely stable.

I'd like to take some ques from Eskimos who also appear to build with dry stack blocks.   I've seen some molded concrete blocks that seemingly interconnect and-or overlap a bit to build retaining walls  and wonder if we couldnt produce a form for geometrical blocks to build either domes or probably better... Vaults.
IF circular or spherical structures are not acceptable then I want to focus on the significant benefits of grooves and tongues that can be molded in concrete blocks that can significantly enhance strength and if engineered can reduce material usage because of the strength.  ( In cases where a structure is calculated to produce a certain amt of strength.... less materials would be required.)    Whenever I cur oranges or grapefruits in half I think of the sections as suitable shapes for dome components... same as when I see soccer balls.  I look at the geometry of the hexagons and pentagons.

Rico Loma wrote:Many good comments, and I am intrigued.  Thanks folks.  
Cristobal, you have a wealth of building experience,  so your word carries substantial weight. I thought the SBC was an integral part of dry stacking.....supposedly giving strength and waterproofing.  And I thought it was only exterior.  If you were building this wall, for example, how would you finish , interior and exterior? I have only used a OPC and fine sand finish exterior with some lime, on a looknormal block wall, then low voc latex paint inside.  

I saw some "dry-blocking" going on recently and it was of manufactured blocks of a new variety. The walls were so smooth that the lines between all the blocks were almost non-existant they were so fine. And the blocks were smooth and white on the wall they were showing. I believe this was on a recent episode of the "This Old House" TV show, I just do not remember.

These were "new technology" and had an interesting looking form of the blocks interlocking with each other. These were being touted as a new method of building a strongly structural house and, I'm assuming, from the looks of the blocks and the light weight they would also be insulating material as well.

A little historical input.

My builder/carpenter  friends tell me a number of the older block houses here in hot and humid Florida have mold growing on the hollow insides of the blocks.

Mold is a major problem here in any building.

Smooth, white, interlocking and lightweight sounds like styrofoam form block, designed to be filled with concrete and rebar to give a continuous waffle-like concrete structure with minimal heavy concrete and maximum insulation.

Ytong/Hebel (aerated concrete), Silka (lime based), expanded clay concrete block and Porotherm bricks all offer tongue and groove systems in Europe. They are mainstream materials available in most cities. They normally are not dry stacked but laid on thin (or normal) mortar bed. They could be dry stacked, because they have very precise dimensions (Porotherm can be purchased with post-firing ground bottom and top). In case of seismic Porotherm the vertical openings could be used for reinforcing the dry stacked wall. Silka is sold with vertical openings for wires and pipes and they could be also used for reinforcing.
ICF forms are dry stacked by design and then filled with concrete. I think they are quite great building method as long as they are natural like Faswall/Nexcem and do not contain synthetics like exterior styrofoam (loved by mice, termites, toxic when burning, nasty when disposed).

Its my guess that over time people have realised bonding with mortar, lime based or portland cement based gives a stronger wall.
But there is more to a wall than the bricks.
- Foundations
- side loads, wind, soil etc
- roof loads
- longitudinal support
- wall width to height ratios
- openings
All theses are normally required in a wall and all contribute to success or failure.

Obligated to all of y'all,  I think someone "tried to sell me a pup" in a discussion months ago, and I saw dry stacked block in the USA as, well, a great unused option.  
Wrong on several accounts, because i now see ferrocement to fill cavitites.... a major amount of effort...is necessary for this idea to be strong, safe, code approved.   Funny, I seem to be easily led astray when my guard is down.  Or, when my BS radar is offline.

As Cristobal posits, Europe and other regions have soooo many choices for clay based block that are all lightweight,  sustainable , and more affordable.  Why can't the US get a grip? Is the concrete industry that dominant here, excluding competition somehow?  I have worked with these Terracotta blocks and they fly together, in contrast to our mundane heavier versions.  
Any ideas about this lack of availability?

Thanks to all the good info on this topic