How Thick Should Stablized Rammed Earth/Adobe Be ?

Building technicials/architects have all the design information and the planning procedures at their finger tips. Their skill is to design it so that it is right-first-time, thereby avoiding costly and time-consuming mistakes.

As a parallel, one wouldn't necessarily use a hammer to put a screw into a piece of wood, when a screwdriver would do a better job...

Hello Slack,

Yes- Quite, but one must also consider the reality of normal life, that not everyone will use an architect and protect themselves , hense the discussion topic.

If plans for failure, one will fail .

Just Can't Wait For Your Replys !

Cheers

Bondjamesbond@rock.com

Know your limitations James.

"If one plans for failure one will fail." - True
If one fails to adequately plan, one will also fail, and possbly kill onesself or others.

No responsible trained person could give you safe advice with the data you have
presented.

You haven't even considered the bearing strength of soil /foundation problem and you
are contemplating a very massive structure.

You should not be doing this large a project with your lack of knowledge - period.

Good luck with the building inspector with a three story, above basement, rammed earth structure without an architect or engineer's certification.

The "foundation" of a good wine basement is the choice of wines. Not knowing what is available to you - Sorry NO COMMENT

If you require a serious reply you should supply detailed information.

Even then you might have to decide between opposing suggestions.

You migh scale your aspirations back a little and settle for a single story no basement dwelling. If you do there are thousands of such structures sprinkled throughout the American southwest to use as examples. Many have outlasted their wooden and concrete bretheren. Forget rebar as reinforcement as it will rust away in a few short years because rammed earth, adobe and such are far more hydroscopic than concrete. Stick with traditional straw. It has survived the test of time. Wall thickness is usually 20% of the intended heighth. You can go to a thinner wall but if your soil is expansive or you live anywhere near a fault zone, thicker is better (and provides superior insulating qualities as well). Back in the 70's Mother Earth News had numerous feature articles on Adobe and alternate, i.e., rammed earth, filled tires, hay bales, beer cans, etc., construction. Suggest you Google as much info, build a garage or a dog house to get some experience or better yet, hire some of our Latin American artisans to do it for you.

I actually tried that, I may be one of the few posters on this thread who actually has some experience. I wondered if this really was an inexpensive way to build. I decided against building with rammed earth because the labour was so intense.

I made an adobe block, a rammed earth block, a rammed earth block with some portland cement in it, a rammed earth block with straw in it, and an adobe block with straw in it. I scraped the topsoil away from my garden, and used the yellowish soil underneath. There was a fair amount of sand in it, about half clay and sand. Once I made the blocks, I left them covered for a year, then uncovered for a year. They were sitting up on blocks. The adobe, with or without the straw crumbled pretty quickly. The rammed earth with the straw lasted all year with the cover in place, but when I took the cover off, it crumbled within a month. (I think the straw wicked the moisture into it. The rammed earth with 10% cement lasted just fine for both years, but when uncovered for a third year, it started to show signs of erosion. The rammed earth with no additives lasted just as long. So adding cement to the mix is expensive, difficult to do if the soil is even a little bit damp and "clumpy", and serves no useful and lasting purpose. Any of the above which were left on the soil simply crumbled after a few months due to moisture wicking up from below.

A gravel road is made of rammed earth. It lasts a long time in the weather. Cement just causes cracks and keeps it from "healing" itself. I once saw a rammed earth house built with a concrete "cap" on the top of the walls. The concrete holds j-bolts to hold the roof down in high winds. Good idea.

Rammed earth is cheaper than concrete, even when you factor in the cost of labour. I would not go higher than 10 feet (3 meters).

Get your building plans approved by your local building inspector. If he won't do it, then don't push the issue...he may know something about your local soil that you don't. The walls are the cheapest part of a house anyway! The foundation and roof are where the cost goes! I ended up building a post and beam...rammed earth was too labour intensive.

In the Taos area of New Mexico There are whole subdivisions of Rammed earth homes. They call them earth ships.

they have learned from experience to make the walls 16 inches thick. That thickness is best for solar heating and cooling, not just for structural strength. This is a very dry enviroment. In the Taos area water erosion is not a problem. You did not mention the type weather you will have to deal with.

Try googling "earth Ship". there is more than just rammed earth info available.

rbeadle@pcc.edu

In Bulgaria Have like traditional construction. There are old houses at some centuries. They are made of clay, mixed with straw .Minimum thick is 50cm./for one storey with high to 4m. /

Foundation made of stone and brick for water-tight. For second storey is necessary frame from wood.

Sorry, I should have answered the specific question...."How thick should it be?" Thats easy. How big a box can you stand in comfortably? Build a box out of cardboard, stand in it, imagine ramming, shoveling, ramming some more, maybe using a power rammer like a "jumping jack". I think my big butt won't fit into a box less than 18 inches across on the inside without squeezing, or shifting the forms. (use slip forms. If you don't know what slip forms are, then google it.) I have seen rammed earth walls only 5 inches thick, but they were not load bearing. Just infill. People who do this work tend to work with 16 to 20 inch wide slip form boxes.

An extra inch can add thousands of pounds to the finished product, but hey, as long as you make a foundation suitable for a stone wall, it will be suitable for rammed earth. You might need some extra concrete for the foundation to accomodate a 20 inch wall, but the materials for the actual wall will be, well, DIRT cheap.

My experiments suggest that earth which is not rammed, but made like adobe, that is to say, like like mud bricks, should have fiber in it. Straw is great fiber. Adobe is NOT rammed earth. Adobe is dried mud. Excellent material for arid climates. My Texas friend lives in an adobe house, and loves it. Its all mud, straw and plaster. Looks great. But its not rammed earth.

(Now to google the code books for rammed earth! Wait a minute...YOU can do that same as me! Go for it!)

I have seen a motel built from rammed earth with about 2 feet thick walls but the earth was not used as a structural member. The roof was supported on steel columns.

Cheers

Some Truly Great Thoughts Gents, & I reply ,in good fun with a serious reason in mind . If I have or do offend you ,please forgive my awkward ways As, I am , it is said, better at destruction, than construction. And Here I Go.Pragmatist : "No responsible trained person could give you safe advice with the data you have presented."Well, I was not presenting Data for an actual construction job , just a topic for a discussion. Try presenting some real data yourself, Dear. Are you sure you're a pragmatist ? Pragmatist think of practical consequences and real effects to be vital concerns. Hence, your next idea."consider bearing strength of soil"Champion, Excellent Point; good data input !"You should not be doing this large a project, with your lack of knowledge - period."As President Ronald Reagan said "Well there you go again Mr. Gorbachev , Tear down that wall . "Wasn't Mind you own ------- business, as to what others should do , The 11th commandment ! "If one fails to adequately plan, one will also fail, and possibly kill ones self or others."Well , I can think of a few, but that would take a real plan & I'm just too old these days .#3 Guest Said:Good luck with the building inspector with a three story, above basement, rammed earth structure without an architect or engineer's certification.Been There, Done That. Thankfully, I know many places including my own, without those people or requirements; And any decent Church Should have burned some of those people at the stake years ago. I also know many that do know this subject & are fine people too. Let us stop saying no ,no, NO you just can't do that , let us then think of : What If & Then How To. There are so many that do read CR4, that have the knowledge to dispel rumors and fears & light the path. But the light is not as simple as just go hire someone or go buy it , its often just go do it yourself with a mindful eye to thoughtful suggestions good posters like you all.#4 Hendrik : "foundation of a good wine basement, is the choice of wines."Very true for wines and I do hope my Norton's do well this season ! Adding 10 more acres this year !"If you require a serious reply you should supply detailed information"It was only a question with very wide possibilities; Add some data yourself old boy, it IS a discussion, not a specific building project.#5 Teajonkwando : "You might scale your aspirations back ,... build a garage or a dog house to get some experience"Been there done that too & See My Last Answer, Please.#6 Yusef1Champion Post Except perhaps, Burn the inspector just after Sunday church, with the other Witches.Guest #7 Yep, Yep, Yep, Great Points and"You did not mention the type ( of) weather you will have to deal with."That's because I was not speaking in the 1st person of need , its more of a general building question, based upon the many questions I receive daily. I'm in the business . I know many on this Rammed Earth path, so religiously Reading David Easton's fine books , building test walls & well houses & animal shelters too. Those people would not hire an engineer to save their own lives, let alone save the engineers life or his income. I do think, were on the right tract with the discussion & most suggestions that have come in are intended as being constructive .#9 Kalchev: "Minimum thick is 50cm./for one storey with high to 4m"Yes, Quite & More; Good point and Bulgaria is truly a lovely country, I remember old Clay structures & some garden walls too.#10 yusef 1"power rammer like a jumping jack"And as I'm in the SE. USA I will say, AMEN Brother ! & I've got a code book somewhere with Rammed Earth & Adobe In It too. Ok, what I'm doing for myself this year & where I am sort of. Were in the Southeastern USA with great soils for foundations Beautiful weather ( Don't Tell The Yankees Please) and there are granite quarries abounding about us ( with tons of free stone sprawls ) . As to rebar & what I'm building : Well, Steel moves in standard ASTM building concrete at say 3000 PSI. at a very differing frequency ( say In a earth quake ) than in Rammed Earth mixes and I agree it should never be used. The frequency will pull the rebar out & collapse the building ; I have read this, but never seen it personally. It's my personal belief, One should think of a Stone building as the model of any Rammed Earth construction , then try and replicate that strength, with an eye toward beauty. I think some of the best looking walls I've ever personally built. were Rammed Earth mixes using Clay 30% Sand 70% & 16% white cement or 32% lime for stabilization . Then add a bit of Charcoal dust in the fray and they become almost marble looking. The thickest I've ever build is 36 inches for a first story structure & 18 inches at the top of the second story. We used concrete bond Beams every 10 feet high and used a form liner to give the colored concrete a stone pattern . Striking Structure ! The basement was 48 inches thick of concrete. No budgeting on this one & there were inspections too. They were not too educated in their government positions and hung around too much I thought , mostly in amazement. A quite lovely private building . This year in my own gardens we are building a 8 to 10 foot wall ( with gate opening tops & terrain) around our 5 acre formal flower garden. It will be a hard job and 24 inches thick . We will use a similar mix as I described above with a 36" concrete & Granite foundation & yes rebar in the foundation on 10 inch square configurations . It will not be Rammed Earth But A Poured Earth Mix In A Form. My Personal belief is Its easy to tie rebar up ( BUT NEVER WELD IT ) & place it in sections after digging the foundation. Ok, now that Iv'e made the world mad with my replies and its 2:05 AM I quit for the day.

Just Can't wait for your ( data ) answers.

Cheers Lads,

Bondjamesbond@rock.com

Guest Post 11 : "as a structural member. The roof was supported on steel columns"

Yes Good Point, 3 marks for you. I've seen this too, as that the fear of public welfare, in a hotel Situ make this a requirement; I recall reading some time ago & the 24" thermal mass is for , Well Thermal Mass, Beauty , Inexpense and so on.

Cheers

Bondjamesbond@rock.com

First Let Me Say To All Those Who Were Nice Enough to write me on the side and ask questions about Rammed Earth & Adobe, Yes I will add more content and building specifics to this posting often.

To begin:

Yes, In South Carolina there are several examples of Rammed Earth (R/E) and the examples go way back. One that comes to mind is the lovely Church of The Holy Cross at Stateburg, SC. C.S.A. Built of just earth in 1850 it is 105 feet Long x 27 feet wide with gable ends 43 feet tall. It is a stately house of God well plastered with a cement pebble-dash wash and at 157 years of age has survived several hurricanes & the 1886 Great earth quake near Charleston, with only slight damage to its tower. It seems it was slightly dislodged from the rest of the building. The steeple was later blown down by a tornado in 1903 and fell across the West End of the church. In 1950, the steeple was restored upon concrete foundations, later in 1963 a Vestry room was added. Due to a leak in the roof, part of the south wall collapsed in 1974. The entire church underwent renovations thanks to a grant from the Historic Preservation section of the US Department of the Interior. Today Memorial stained-glass windows of modern construction installed in 1976 lights the interior. The Church of the Holy Cross- was declared a United States National Landmark in 1978.It survives today as a testimony both to God and to good planning, wise construction methods and the foresight of preservation.

We are in what I think of as the 3rd revival historically of R/E and it is due in part to the current economic conditions and old knowledge coming to light to those with an open mind. A home that is paid for is a great thing and solid walls , floors & even roofs made of non burning, low cost, low tech but highly effective materials makes it even more attractive in 2007. Our History has taught us many things 1 must be to build upon the past and maintain it well to educate all from.

More Later

Cheers

Bond

Bondjamesbond@rock.com

Just A Tag So I Can Find This Page As A Member - Or Should I Say Browser.

Bond

Dear Sir,

I've Heard Of Your Work In Georgia & That Was Put Quite Finely !

3 Cheers For Our Side.

Bond

Bondjamesbond@rock.com

Hello ,

For those interested in further information about this subject , Please join our new Yahoo Group Forum At:

http://finance.groups.yahoo.com/group/georgiaadobeforums/