Throughout history there have been efforts to introduce additional constituents into adobe mixes: gypsum, lime, Portland cement, emulsified asphalt, straw, manure, horsehair, grasses, molasses, and so many more things. Too much asphalt such as in fully stabilized adobe bricks and the lime may not adhere as well. Is emulsified asphalt a liquid or is it goopy and needs to be heated? I had the Daraweld dealer stop by and explain how his binder could be used with adobe. Wheat straw is the most common but if you can find barley straw it is a bit tougher. Also look around your area to see if there are old adobe buildings. You can buy it premixed in a bag from Quickcrete which is the most widely distributed in the West these days. Q: I've been experimenting making some blocks, and lab tests have shown me that my soil is 74.4% sand, 14.0 silt and 11.6% clay. Will it bind with the clay walls and not crack due to clay breathing? Use no paper or other moisture/vapor barrier under the stucco and it will breathe sufficiently to work with adobe. The solution is to find and eliminate the source of moisture. Q: My husband and I are making a small structure from adobe bricks. I would like to know how I can achieve a smooth wall; it is uneven with the bricks and it doesn’t look very nice. Otherwise, you might want to add some Portland cement (maybe 5-10%) to help stabilize it. I worked shoulder to shoulder with Michael Valdez for 18 years. Later, he traveled a bit, went through the as the Project Manager and Instructor for the Sundwellings Demonstration I have no experience with rice husks/hulls so have no idea how attractive they would be to termites. Our clay plaster water cures into an incredibly tough finish that is hard to describe. Well built it should be good for a thousand or so. I can’t find instructions on how to mix horse manure to finish the wall before painting. Q: What about using cement plaster over adobe? There must be mineral deposits in your clay and/or sand if your are seeing residue in the rain puddles. So much has been written that we have ended up with Jumbled Text. Some natural soils make bricks that are surprisingly water resistant. If I mix 3 parts of dry powdered fire clay with seven parts of sand would that give me the consistency I need for the adobe? will out-gas for a long time as the solvent evaporates. I don't think there is anything you can do to get rid of it. I There might be some other bulk asphalt plant that supplies road or driveway repair contractors. I don't think that Portland cement is the right thing to add. Should we fill the air pockets with mortar? if the salt content of the clay might be a problem. Q: I am a Ph.D. research candidate working on "Efficacy of Selected Local Stabilizers - Rice-Husk-Ash, Straw & Cow Dung, on the Stability of Earth Buildings". The metal expands at a much higher rate than the plaster. My doubts arise from the fact that the bricks I made without cement or lime broke up easier when dropped. I have been using asphalt emulsion in my mix (about 12 oz to a wheelbarrow full) , to attempt to waterproof, but my plaster seems to be eroding pretty fast already. A: Bitumen, bituthene, pitch, brea, la brea, it could all get turned into beechmo. If you are in doubt you can add a pint of Elmer's Yellow Carpenters glue to each wheelbarrow. Q: I am almost done laying adobes for my courtyard wall in Albuquerque. Any advice? Don't stop there. Local construction supply stores give me a blank stare when I ask about availability of adobe type soils. Throughout history there have been efforts to introduce additional constituents into adobe mixes: gypsum, lime, Portland cement, emulsified asphalt, straw, manure, horsehair, grasses, molasses, and so many more things. CEB's are made pretty dry so emulsified asphalt cannot be used as a stabilizer. Some folks just make a lot of forms and let the bricks dry out for a few hours or a day. I just sent off a long note on how adobe structures in Hatch and Albuquerque, NM hold up to three day floods better than frame houses. Adobe walls always find a way to pick up some moisture whether from the ground - called "rising damp" in Europe and other parts of the world - or from wind-driven rain striking walls or cracks in wall/parapet plaster or roof leaks or elevated air moisture from internal sources within the house. How can I restore these walls, using modern building materials such as cement if possible at all? 30/70 also makes a good mortar to stick it the adobes together. I am pursuing my thesis in the Rural Studio, which focuses on Green buildings and housing the unfortunate poor of Hale County. Although they do not help reinforce the bricks or give them added long-term strength, straw and grass do help the bricks shrink more uniformly while they dry. It is easiest if the cookie sheet has low sides around it, about a half inch. The soil composition typically contains sand, silt and clay. If I buy semi-stabilized bricks and cover the wall in a mud plaster of the same semi-stabilized mix, would a lime wash be compatible and would this combination be durable. Or should I really use none. It was packed out most of the way but not finished before winter. but otherwise mix it the same as I did for the mortar, semi-stabilized A: In all likelihood you can count on your adobe suppliers statements. Straw is one way to keep bricks of higher clay content to keep from cracking when they dry out. Natural plaster is similar to cob, but adds manure and wheat paste for better adhesion, strength, and smoothness. A: These days, emulsified asphalt is the preferred stabilizer. At the same time we expect stucco and other wall coverings to keep liquid moisture from moving into the wall during a rainstorm. A: Most CEB's are stabilized with cement. Once cured, the asphalt molecules are electrically bonded to the clay molecules and cement molecules are chemically bonded to the sand particles. If the soil is expansive then it will be hard to make bricks that do not shrink and crack too much. I have some bricks in my yard that came from an old house ten miles up the canyon and they take several days to melt. I have read from many sources (including your website) that cement is commonly used in adobes. Yes indeed the 30/70 clay/sand adobe brick is the best for strength. If it just goes pleth, pleth then it is friable and may not hold up. Miniature bricks can be made at any size in smaller forms. I think you just need to make some test bricks at 5 and 10%. Then cover them with water and hope the wheelbarrow does not leak. What would be an ideal block size for an earthquake region, 300x300 mm or must it be bigger, up to 400x400 mm? Some people think that adobe and cement based plasters are not compatible. His website, quentinwilson.com, lists the course schedule and many other resources related to working with adobe. reduced resistance to moisture. Kelly Hart, Hartworks LLC. A: Emulsified Asphalt: 1 to 5%; Cement: 3 to 7%; Lime: 2 to 9%; Fish oil emulsion: 1 to 3%; Carpenters glue: 1/2 to 2%; Resina or latex/acrylic: 1/2 to 4%. Besides the ability of earthen materials to moderate temperature changes, the plaster will participate with the moisture in the air and will also moderate humidity changes in the interior space. You would then need to find a clay course and there should be some in the Barbados. I prefer to keep the experiments in the laboratory. Adobes can actually tolerate at least a few stones up to 1/3 the thickness of the brick. I don't think there are any chemicals in horse/burro poop that will provide strength or adhesive abilities. Adobe is easier than anyone might think. We are located in Ganado Arizona on the Navajo Reservation about 70 miles north-northeast of Holbrook Arizona. In New Mexico, wood ash has been historically used in adobe bricks. No layering of sand, rock or anything. You have to have your own barrel hopefully one with a removable top. Any thoughts on how to check my available soils before I hand ram something that lacks the desired integrity? It is useful to note at this point that with all the talk about breathability which is the down home term for water vapor permeability/transmission, no one has measured the permeability of mud walls. Besides, I ran a block plant over a couple of years and just plain had my fill of cement and lime so I may not be the most objective person around. Chopped straw can be added but is not absolutely necessary. We checked the soil and think we have at least 10% clay. Then the plaster dries enough so there is not enough moisture to freeze. They are currently laying the block. Too much troweling and the plaster will fall off especially where it is thicker. Stucco is the best value and the most efficient wall finish available. They supply to the highway and driveway repair industries. Have you ever heard of treating fiber or rice husk with borax? Q: I live in Northern California and want to build an outdoor adobe oven. You can work outside on the ground or if rain is expected within a week there might be a dirt or concrete surface under a roof but hopefully arranged so that some sunlight hits the surface. I am wondering if this can somehow be used in the construction of adobe brick? Openfos The US B2B Directory. Some of the mortar was replaced on this wall before we bought the home and it is starting to come out again in the same place. In Northern Mexico and at Simone Swans in Presidio Texas there is interest in combining a little cow manure with prickly pear type cactus fermented in a drum for a period of time. Or mud plaster. Q: I am a 32 year old single mother of 2, who got 15 acres awarded to me from the divorce. It is always hard to predict how any particular block will handle moisture and freezing. This code requirement is a functional requirement, not a stated amount since different stabilizers in different soils act differently. We have found that just plain natural adobes work fine and on some occasions we have used asphalt stabilized adobes. If they survive, they are good. We started to fool around with our local prickly pear cactus but we got so busy last May building what was then our largest dome that we forgot and let the cactus dry out. Which block will become better or harder: a sun-dried block or a block dried in the shade? Would this material be a suitable substitute for adobe soil? Built in 1887 from sun baked adobe. Usually the person claiming that the extra ingredient is absolutely necessary also happens to be the person who ever so kindly will sell that material to the brick maker. Squash em, kick em, leave em in the rain. It seems similar to "straw clay" but is rather "horse clay", with smaller fibers. Too much sand has little effect on the strength but the bricks are less water resistant. Each lodge will be build like a small Ethiopian Orthodox church with wall decorations and paintings. What method, material, ratio, process might you suggest? A: I think that your use of horse manure is perfect. Whether you choose clay or lime plaster for your walls and ceilings, be assured that the natural material will create a beautiful, healthy, and comfortable home. The best adobes are made with 30% clay and 70% sand. Good stucco in Taos can last 60, 80 years. In regard to Mosses. A high perm wrap would be much better. I will be putting a lime plaster on the rest of the wall. Adobe bricks have been made with those materials throughout history. It makes perfect bricks but I don't get a lot of volume. These walls are 4", sometimes a thin as 2". We just replaster the ovens every year or two. I feel strongly that adobe should be made as simply as possible with the materials at hand. Clay and straw are mixed together to make _____. It has some kerosene in it sometimes and is not much fun to work with. I was wondering what construction methods would work best in Alabama. I can never remember which is the right one but the company or a distributor should be able to advise. Whether or not you need to wet the wall before plastering is another question to be determined by doing it. If that happens you will know when chunks of plaster fall off instead of erosion of the surface. And how fast does Adobe melt when exposed to the elements. 1.) Every soil is different in its clay/silt/sand ratios so it just takes fooling around. That's about a 3- to 4-cubic foot load in the wheelbarrow. Also, would it still help cool the room if the walls are made of brick and lime. In fact, the Hans Sumpf story which I don't remember well had something to do with just trying to figure out what to do with a mountain of dirt left over from some industrial or agricultural project. It's in many places around SE NM. It is a great way to cover up the somewhat toxic surfaces produced the past several decades. By "same material" we are cautioning against the use of cement/lime/sand mortars or heavily lime or asphalt stabilized mortars unless that is the make-up of the bricks. I do know that there is some adobe construction in the SE part of Jamaica. Small cracks are no big deal. Having read that 20-30% clay is optimum, what disadvantages will be present in my blocks if my soil only has 11% clay? After a while a green sticky goo is produced that can be lifted out and added to mud to make a fairly waterproof plaster. There is always another source of good clay a few feet down or a mile away. Q: With my wife, we have recently established a private company in Ethiopia for an investment in eco-cultural lodge in Lake Tana area. I dealt with Jeff, and the transaction was simple and straight forward. It would save you money but once you paint stucco you can only go back to stucco after sandblasting, treating with a stucco bonder or hand scraping. Usually, 70% sand and 30% clay makes a perfect plaster. Do you know of a place in Baja or in Southern Cal where I can purchase it? A: (Kelly) This is a pervasive problem with domes and vaults, and my best advise is to first repair any large cracks as best you can, or perhaps even replaster the entire dome using fiber-reinforced stucco. Therefore, to get successful soil/cement bricks it is necessary to test each soil to be used to determine the percentage of cement that will be required. What could be the effect of using such chemicals on a block? You will be proud of yourself one day soon. Portland and most clays are not compatible and so the first bit of cement added goes into overwhelming the clay and then the balance of the cement takes over the bonding duties. You just have to dig below that pesky top soil down to sand and clay and gravel strata below. History would have been different. However, I want to pass this long winter building adobes from a hole that will be my future root cellar. Do you think my soil has too little clay? If you go in more than an inch it is better to do it in two steps filling half the depth and about four hours later the outer half to avoid cracking. Q: A: If you can angle grind a channel that is wider on the inside than on the outside surface of the stucco that will be the best solution and may be just what you mean by a key. One of the questions we have is how to identify adobe stabilized with asphalt emulsion. A: Africa is a vast space and I have never been there yet. We then used acrylic based adhesive always looking for the one that proclaimed the highest resistance to water incursion. I have access to clay / shale that is used to make fired brick. See this page. What is an alkali salt? I have seen no improvement when clay content is low. If it is so waterproof that it does not breath, then water vapor cannot get out and large chunks of the plaster fall off. Horse manure was often used in making adobe bricks. Adobe Plaster Of all the options, adobe plaster, also known as earth plaster or mud plaster, is the one I like the most. Silt and other materials are often found in soil and add no value to the strength of the material and sometimes decrease it. and taught the full-time Adobe Construction Program at Northern New Mexico Or make friends with a gravedigger. The wet season can really be wet but it does not last more than 5 months in total. you can make adobe bricks. You can and should use the same mixture that you used for bricks and mortar. I stick with just plain mud. A: Some soils that will make adobes will not work for CEB's and vice versa. ly.cal seminar in Santa Fe this summer. Adobes did not wash away. Since the contractor could not finish it, my husband and nephew stepped in. No one I know has done it so you will be blazing new trails. He wanted to do one of adobe with my help on design and consulting before he died. I am having trouble finding this. Mix the ingredients thoroughly so that no clumps of dry plaster are left behind. If they are there, then you should have no problems. A: A lime plaster would be great if you can find someone in your area to advise you on the technique. Crocker and his crew first strip off an adobe wall's existing—typically cement-based—plaster to assess its condition. A: Well, this is a new situation for me. Exterior Plastering: the rainy season can be very wet and in order to protect wall frescoes on Adobe, stabilization of mud plastering (or other material) is a main concern. certain concentrations can prevent the ability of clay to bond Q: I'm in the process of building my adobe courtyard wall in Albuquerque, almost half way. That should not happen on an interior wall so I think that you can easily omit the cow dung for interior plasters. The equivalent in wood buildings is rot or peeling paint. Once a few test bricks are made you can test them for compressive strength and at the same time for modulus of rupture by dropping them from knee height. I teach the Adobe Construction Program at Northern New Mexico College in El Rito. I've read that I could use a sand/cement mix of 10 to 1 which will be 'soft' enough not to break away from the adobe brick. He always wet the wall, I never did. bricks being made. He grew However, thousands of adobe homes -twenty-five built by me - in the American Southwest and Germany have exterior cement/lime/sand stucco applied directly to the wall with no wrap since they were built before the code required wrap. What treatment(s) are possible/necessary for the straw & Cow Dung to avoid any adverse effect of their organic content on the earth material. Most ovens collapse from exterior water problems. A: There was a man in Montrose who had built five houses. Still no one with actual experience with the material with respect to adobe. It rains a lot here and for the plastering we are going to use our own soil, but what do you think we should mix it with for the outdoor plastering of the house and what should we mix the soil with for the indoor plastering of the house. Somewhere in your area there should be sand and it might be down a few feet below the serface of the ground. Maybe a quart. Many of the mixes used, are almost as old as the dirt we stand on, and passed from generation to generation. Steel will rust. We will have to replaster two this spring. There must be mineral deposits in your clay and/or sand if your are seeing residue in the rain puddles. The best patching material for adobe bricks and mud plaster is the same material as the original. It will stick to adobe and breathes well. When we plaster an horno we rely on the ability of the earthen plaster to stick to the mud bricks. The final color coat can be a nice Santa Fe Brown. I would like to build a home either using Adobe bricks or plastered mud. A: That might work. Seems to me to have been one of the earlier recorded incidents of government interference in the lives of owner-builders. Q: I intend to stabilize the adobe with pozzuolana ash like Rice Husk Ash or Silicafume. We live in Colorado and it's getting cold at night, can that be part of the problem? Lots of Arizona homes use exposed adobe. Every soil acts a little differently to the addition of stabilizer. Short of standard stucco systems on a good moisture/vapor barrier we still don't have that figured out. Use a trowel to apply gobs of the plaster in small patches at a time. I have lost his contact information but he might have set up the adobe yard. A: For a fired brick wall, the simplest repair method would be to use standard cement/lime/sand mortar which is most likely what was originally used. If you can find the highest clay content that will not crack that will give the best natural water resistance. I have not heard of dogs with a taste for adobe. Bricks that survive the drop test have been found to be roughly equivalent to 300psi compressive and 50psi modulus of rupture. Q: Almost finished with an earthship in NC. You might also look around to see what the local populations have developed where there is still earthen construction. An inch wide by an inch and a half long is a good size. If so please tell me what and how to go about doing it. You get mixed reviews since no one really knows all the details of your local soil. And since I've already started with the asphalt emulsion, is it too late to try other kinds of waterproofing? Sodium silicate? No one has measured the permeability of adobe yet. What does this mean? Interior walls can and should be unstabilized.  Some people are uneasy at the thought of asphalt in the walls which is then in contact with the air in the structure. And the bit about the chopped prickly pear is interesting. If I placed the blocks on a well draining foundation of gravel and sand, and 'sealed' the blocks with linseed oil, and reinforced the adobe block with cement, would these blocks withstand wet weather and winter conditions? If asphalt stabilization works then my guess is that linseed or tung oil would work. By age thirteen he made full-sized adobes in the back Here's my questions: What will theoretically give the best block, a block with only soil and sand, or a block with soil, sand and rice husk? For a culture that is used to frequent maintenance that is acceptable but for the Modern American Ethic, long term solutions are the sought after ideal. There are 5 different bioregions on the island of Maui alone and I am only hand tamping the forms so far. A low perm wrap would be bad for earthen walls or any walls, for that matter. The interior can be: What is your recommendation for filling the channels? Semi-stabilized chunks after three weeks will be mud or very mushy chunks. Basically, with adobe everything works. What alternative plaster could I use that would be lower maintenance and stable? The Mexican asphalt I have seen was "cut" asphalt which had a solvent rather than an emulsifier. I don't think that is what you want to do. Lime wash should be able to get a grip on the semi-stabilized plaster. Does anybody near my area carry bags of material to make bricks myself that I can just "add water" to? which to make adobe bricks. Just try fooling around with the coral dust to see what happens. You might also be able to find some latex/acrylic at a paint manufacturing facility.  Aggregate is always good for adobe bricks and particles up to 1/3 the thickness of the brick can be tolerated. I used standard cement/lime stucco over adobe homes new and old for 25 years with no problems. Cancer got him before he realized his dream. About 1986. If the walls get wet, some of the pressure of unrelieved stresses at the particle level in the CEB's is released and the bricks "blossom." or too much? Associates, specializes in solar adobe design and construction. I specifically disclaim any warranty, either expressed or implied, concerning the information on these pages. Could you give me some information on where to purchase an Adobe Block press and possibly a good strong Adobe Block recipe? I have never used a 1/10 mix but it might work. You can't use much more clay without experiencing cracking. With the addition of sand, the mix will begin to fall off the blades and back to the bottom just as concrete does. Q: I am doing some archeological work analyzing some historic adobes in Big bend National Park. Indeed the blocks can be expected to survive better if the patio is covered. I am doing the interiors of a ready made apartment, but really wanted to coat the walls with an earthen plaster. Neither I nor any of the advisor/consultants associated with this site will have liability for loss, damage, or injury, resulting from the use of any information found on this, or any other page at this site. As little as 7% clay will work and up to 45% clay will also work but the bricks are more likely to crack without the addition of straw or some sort of fibrous binder. a major in physics, minors in math, chemistry, and education in 1970. His whole purpose of using adobe is for conserving energy and plans to use a wood stove only for heat. takes about five days or a week to dry enough to handle. No one I know has done it so you will be blazing new trails. An adobe brick is a composite material made of earth mixed with water and an organic material such as straw or dung. It's much more satisfying, low impact (and inexpensive) to use your own dirt … You would only need about 9% of the total weight of the brick. Montrose does have a nice college with some pv collectors on the roofs. The asphalt I have seen in Mexico is not as thoroughly emulsified and has a bit of a kerosene smell even after the adobes have cured. If the soil has the right blend of clay and sand then it can work as is. Adobe gets As soon as it will not slide easily off a trowel or shovel, it is too much. CEB practitioners might have more ideas. A: Alkali salts is the white stuff on top of the ground that is left after ground moisture evaporates. Tire pounding would probably be good exercise but I don't know if I'm up to it. By normal, I mean natural or unstabilized. A: You can certainly plaster over adobe bricks. It can be applied by hand or machine over gypsum or metal lath, clay tile, concrete or cinder blocks and other approved plaster bases. By age thirteen he made full-sized adobes in the back The closer to single fibers, the stronger the bond of straw to adobe. If the coral provides the sticky ness, then you only have to find lots of sand to add to it to get a great brick. Project at Ghost Ranch, Abiquiu, NM. They keep cracking and we don't know what the next step should be! It is my opinion that just plain adobe is the best material. Non stabilized materials will dissolve straight away. Just fool around a bit until an appropriate blend is discovered. I am guilty of confounding a situation myself by mixing arrogance and ignorance in the same breath, so..... my job is to come and reason together in peace.