TEG Tour – July 9, 2023
Hacienda de Los Martinez was the site of our July TEG Tour. Over 30 TEG members and guests were treated to an update on the work to be done on the Martinez Hacienda, its history, and a Tour of the grounds. A bonus, the museum had a beautiful Colcha Embroidery exhibit up. Daniel Barela, executive Director of the Taos Museums was our host. A living museum of late Spanish Colonial period in Northern New Mexico, the Hacienda was built in 1804 and is one of the best surviving and preserved Spanish Colonial house in the American Southwest. TEG member Pat Taylor will be leading a workshop on September 1 & 2, 2023 at the Hacienda in the first of their efforts to begin restoration work on the Hacienda. If you are interested in attending send an email to theearthbuildersguild@gmail.com and we will send you the information as soon as it is released.
Pat Martinez Rutherford - TEG Board Member
Next TEG Tour and Board Meeting
The Earthbuilders’ Guild’s next Tour will take place on Saturday, September 9th in Ruidoso, New Mexico at the Old Dowlin Mill at 1:30pm. The Mill was built in 1868. It is Lincoln County's oldest landmark. It suffered major damage in December of 2017 from a gas explosion. Fire burned the interior of the building and the mill house burned nearly to the ground. The water wheel narrowly escaped the blaze. The roof was lost but the adobe walls stood. TEG member Rob Taylor has been working on the restoration of the building. We will be touring and seeing the progress of the work. Please RSVP by Sept. 6th. Non members $10; Members free. Our Board meeting will be held that morning. If you would like to attend the Board meeting by Zoom contact Pat for RSVP for Tour and/or meeting: theearthbuildersguild@gmail.com
Pat Martinez Rutherford - TEG Board Member
The Old Dowlin Mill – TEG Tour on Sept. 9, 2023 – Ruidoso, NM
This update picks up after the article in issue #20. The old Dowlin Mill in Ruidoso exploded from a gas leak in 2017. The roof was blown completely off, doors and windows blown out and the resulting fire gutted the interior and floors. The only thing left were the adobe walls and stone masonry of the foundation.
Restoration work began in late 2019 until cold weather put things on hold. In about September of 2020 work resumed until the end of November. Spring of 2021 saw work start up in earnest and by December the side walls were complete, new trusses built and set and a roof put on. While far from complete, the building was now fairly intact and sheltered from the weather.
In June of 2022, work started again. Due to the urgency of getting a roof on before the previous winter, the block laying efforts were focused on the north and south walls on which the trusses would sit. There was still significant damage to the gable end walls, but since they were not supporting the roof structure, repair to them was put off. This is where work started. Scaffolding was set up to finish the east wall then moved to the west side to finish up there. As always, there was a significant amount of repair to be done to the old adobes in the walls and the mud joints between them. Blocks that needed fixing in the walls on the outside had been taken care of as we were laying new blocks to bring the walls up to height. In many places it was necessary to cut out damaged or eroded blocks and replace them. This is a delicate procedure as it is necessary to support any weight of the wall above them which can be several tons depending on location. The damaged block on the inside were generally not accessible and repair to them was put off until the roof was on and the remaining shoring and bracing had been removed. Many hours were spent dry packing old joints. This is a process where a clay and sand mixture is moistened just enough to force it into the voids and hold together without shrinking until dry. Mud grout will not work in this situation as it will shrink and crack as the excess water dries out.
In September, a pair of stonemasons joined the crew to build the stone and lime collar on the south side that will protect the adobe that is below ground level. The rock for these was brought in from an old quarry near Corona N.M. This same material is being used throughout the building to repair damage and voids in the masonry.
The next big phase to tackle was the removal of about 250 cubic yards of fill dirt that was inside the building. When the mill was originally built, the south-east corner of the building was cut into the hillside and the wall sections that were below ground level were built out of stone, including the footing. Over the years, erosion off of the hill has covered the footings and piled up against the adobes. On the north side, which faces the street, the walls have been forced below ground level by the continued buildup of the road base over the last century. With the exception of the far west end, the entire building now sits below ground level. While this has been an ongoing problem for decades, it became especially acute after the explosion tore the roof off. The walls of the mill now formed a basin to hold water after it rained. To stave off rapid deterioration of the adobes, the interior of the mill was filled with dirt, sloping from the east end to the west where a door at ground level would allow water to run out of the building and into the gutters under the street.
With a roof in place, we could now remove the dirt ramp from the inside of the building and once again expose the footings and adobes that had been buried under good intentions. When the dirt had been brought in, there had been about a 12’ hole in the north wall where a truck could back up and dump its load inside. Then a track loader was used to spread and grade the dirt as needed. Since we had rebuilt the walls, this opening no longer existed. Realizing this would be a problem, I had convinced the owners to convert a window on the south side into a door large enough to get a small loader in and out of. I must point out that “large enough” is a relative term when it comes to heavy equipment and bigger is always better. Anyway, the six and a half foot opening that was big enough for the tractor I was operating at the time only allowed about 2” of clearance on each side for the tractor we ended up using. This is where you separate the wheat from the chaff, and I took the initiative of hiring a far more experienced operator to handle the task. With a bucket that held about 1/3 of a yard, it took somewhere around 700 trips in and out to remove all of the dirt.
By this time, the weather was cold again and even Ol’ Smokey, the double barrel wood stove was working hard to keep up. The masons had to pull off in November. The windows were covered with plastic and the doors boarded up and work tapered off for another winter.
Rob Taylor - TEG Board Member
If you are interested in attending this Tour, please RSVP by Sept. 6th. Send an email to Pat at theearthbuildersguild.gmail.com. Members Free, non-members $10.
Albuquerque Joinery’s Latest Adobe Build
Albuquerque Joinery’s latest adobe build is underway, again in the Los Griegos neighborhood of Albuquerque’s North Valley. The project consists of two buildings – a 1,750 sq ft house, and an 800 sq ft workshop – situated on a small, agricultural lot.
The house, nestled up against a shady irrigation ditch, will incorporate passive solar principals in the south facing rooms. With an 8/12 pitched roof, we sought to preserve the scale and proportions found in traditional adobe architecture, particularly in a northern New Mexico style. An efficient galley kitchen will lead to a centrally located den with a Rumford fireplace. The east and west wings house two bedrooms, two bathrooms, and an office with interior French doors.
The second building is an exposed adobe workshop, and provides a space for garden tools and woodworking. It will have a simple bathroom, cathedral ceiling, and a wood burning stove. The exterior adobe will be left exposed, with mud plastered buttresses and carriage style garage doors.
Planning for the project began in 2022, and after some permitting delays we finally broke ground in May of this year. The two structures are being built concurrently.
Some unexpected requests from the City of Albuquerque Planning Department included a stabilization test of the adobes, and engineering on the solid wood bond beam. The stabilization test demonstrated that our sample of the semi-stabilized adobes produced by New Mexico Earth in 2022 absorbed less than 2.5% of their weight in water, making them, per code, suitable for a finished exterior surface (they will also be further protected from the weather by the eaves of the roof). For the 6” solid wood bond beam, our engineer specified a 12” lap with ½” through bolts. Additionally, we’ll be bolting the bond beam through the top four courses of adobe at roughly 4’ intervals. Although we believe this goes far beyond what is prescribed in the New Mexico Earthen Building Code, our plan reviewer insisted on the additional engineering. It will, however, benefit the building if a seismic event ever occurs, and we are interested to try out this new system.
There were quite a few new faces on our job site in the month of July. We took on three interns from the Santa Fe Community College Adobe Construction Program, who each spent 40 hours working on our project for college credit. The Albuquerque Joinery team – adoberos Kenny DeLapp, Nathan Demar, and Erik Navarro – also taught a workshop sponsored by the nonprofit, Adobe in Action. Six participants received hands-on training in adobe wall construction, mixing mortar and laying adobes for the build. We look forward to future partnerships with these organizations in service of our shared goal of continuing the building heritage of traditional adobe construction in New Mexico.
Esther Fredrickson – TEG Board Member, Albuquerque Joinery
CEB Certification, Part 3 – Discussion of Machinery Understanding
In my initial article (TEG Newsletter 1/23) I described four specific issues that should be addressed if TEG is to offer a CEB Certification test. These four are materials understanding, machinery understanding, operations understanding, and expertise availability. This current article focuses on the machinery inherently needed to manufacture CEB and how best to determine what constitutes the demonstrated knowledge of these mechanical systems. I would like to note that for the purposes of these articles I will use the term “CEB” to avoid confusion, but please bear in mind that the addition of a stabilizer creates what we call a “CSEB”, a compressed stabilized earth block, also I will occasionally refer to CEB as “pressed blocks”. Also, please note that I am not a mechanical engineer, and some of the claims I make in this article are based on empirical rather than educational knowledge.
Importance of Mechanical Systems for CEB Production
Simply put, if you cannot compress the earthen material being used to make earthen blocks, you cannot produce a compressed earth block. Additionally, if the mechanical systems cannot produce enough force to achieve a reasonable level of compaction, you cannot produce a viable CEB. These two requirements guide the decisions and the outcomes of CEB production and therefore must be at the forefront of the mechanical area of CEB certification testing. There are numerous types of block pressing mechanisms and machinery that exist, and the challenge it would present to test for each type of machinery is too much to expect of a certification test such as we are hoping for. Instead, if we test for the knowledge and understanding of the basic premises of any CEB block press we should be able to determine if the applicant is suitably capable of making a viable CEB. This comes back to the issue of safety of the product itself. CEBs made poorly look and feel generally just like excellently made blocks and it takes a trained eye or expensive mechanical testing to determine with confidence if the blocks are capable of being safely used. This means that certifying the ability to master the machinery is every bit as important as certifying the knowledge of the earthen materials. Additionally, certifying based on these basic premises ensures that the applicant will be able to take any machine and make safe and viable CEBs.
The block pressing mechanism, while being the critical piece of equipment, is certainly not the only piece of machinery that should be included in a certification for CEB production. The need for soil preparation machinery, and how to ensure that it can produce block press ready materials, should also be demonstrated. Additionally, there are any number of supporting machines that affect the quality of the produced CEB, either directly or incidentally, and these machines should be part of the certification testing from the perspective of how and why they affect the block production.
The Block Pressing Machinery
Having a working knowledge of the primary mechanism for producing a compressed earthen block is the most important aspect of any CEB certification effort. If the applicant does not have the necessary understanding of this mechanism, the certification for CEB production should, arguably, not be awarded. If the applicant has familiarity of and experience with a specific machine type, it should be part of the certification process to have the applicant demonstrate the foundational aspects of this particular machine and how well the machine performs these aspects.
There are multiple variations of block pressing machines worldwide. Having a working knowledge of all types is not only impractical but is also not feasible since TEG does not have the resources to have one machine of every type on hand for the certification process. Perhaps then, the emphasis should be on being able to take a rudimentary machine, one capable of making a single pressed block per cycle, and produce a block deemed acceptable for safe use. This would obviously mean that the applicant would need to take time to use and understand this particular machine, but if the applicant already knows the foundational issues, then learning the details of a fairly simple machine and being able to take a suitably prepared soil mix to make an acceptable block should not present too high of a hurdle.
There are numerous aspects of any block pressing machine that must be understood and adequately demonstrated as part of the certification process. This includes the ability to modulate both the time and force of the pressing cycle and an explanation of why these two aspects are so very important to the success of CEB production. This additionally includes the ability to explain the actual force generating system both in the rudimentary TEG machine as well as their preferred commercial block pressing machine. This should encompass the type of force-generating system, such as gasoline/diesel engines or electric motors, as well as the force delivery system, such as hydraulic controllers/pumps/lines or mechanical linkages that apply the generated force. Another aspect that demands understanding is the mold type, including monolithic, stepped or angular, and hole producing molds. This is particularly important in regard to how the machine, with a specific mold type, must be operated in order to produce a viable block. A clear understanding of the advantages and disadvantages of each type of mold should be demonstrated irrespective of the machine type that the applicant is familiar with.
To sum this up, there are some universal aspects of block pressing machines, the demonstration and knowledge of which probably present the most reliable approach to this piece of a CEB certification.
Supporting Machinery
There are numerous important and much needed pieces of machinery that provide the means to produce consistent quality and quantity of blocks. However, with a shovel and a block pressing machine, blocks can be made. So, the question in this sense is, what additional machinery should be included in a CEB certification process?
A good argument can be made that the next most important piece(s) of machinery in the CEB production process is the machinery for mixing and preparing the soil prior to putting it into the block press. This is because the degree to which the soil is correctly prepared has a substantial, even critical, impact on the quality of the pressed block. In this regard however, there are quite a few methods of soil preparation, with many different solutions being employed leading to relatively large differences in the final press-ready mix. However, regardless of the type of preparation machinery, whether standalone blending machine or pit mixing with a rototiller or pug mill and conveyor, the basic idea is to have a mix that is as homogenously mixed as possible, especially regarding the introduction of stabilizing agents such as Portland cement or lime. Given this goal, part of the CEB certification process should focus on the applicant describing how different methods of mixing and types of machinery achieve this goal.
Additional considerations for equipment to provide wetting/hydration of the soil mix prior to being fed into the block press should be part of the certification process. The ability to control the amount of hydration as well as ensuring incorporation into the soil mix should be well understood, especially if stabilizers are being used. The hydration level is crucial for complete activation of the stabilizers so the most complete incorporation as possible is always desirable. The basic issues for a CEB certification will include an understanding of proper hydration as part of the materials aspect, but how to achieve this hydration using equipment should also be included.
For many of the aspiring CEB producers, the above machinery and equipment should suffice for making viable, safe pressed blocks. However, additional machinery should at least be mentioned and questioned regarding the benefit that each piece brings to the operation. This includes earth moving equipment such as loaders, skid steers, tractors, conveyors, etc.; logistical equipment such as forklifts, trucks, trailers, etc.
Final Thoughts
Many CEB producers use all of the above discussed machinery, sometimes even additional machinery that may not need to be part of a CEB certification, but that is not to say that all pieces are needed to produce an adequate, or even excellent, CEB. The knowledge of the operator of the machinery is substantially more important than having all the above discussed machinery and that is what a TEG CEB certification process must focus on.
M. John Jordan; TEG Board Member-at-Large; President, Paverde LLC
Seeking Adobe Bricks
TEG has been receiving inquiries for a source of adobe bricks. A recent one is seeking to purchase 3,500 bricks in Northern New Mexico. If you know of a source please contact TEG and we will put you in touch with the folks looking to purchase. theearthbuildersguild@gmail.com
Pat Martinez Rutherford - TEG Board Member
Light Straw Clay Insulation Workshop
with Franz Volhard
In late July I was lucky enough to attend a Light Straw Clay Insulation workshop in the Uckermark region of Germany taught by renowned architect, earthbuilding specialist and author Franz Volhard. Light Straw Clay is a time tested, owner-builder-friendly technique for insulating walls and roofs. Clay is stirred up with water and mixed with long straw to create a building material with a dry weight of around 1000 kg per cubic meter. With a relatively high proportion of clay, the material has high strength and elasticity and is easy to place into wall and ceiling cavities. See some of the workshop techniques in action in this video (a mix of historical and modern applications):
Kurt Gardella - Adobe in Action Executive Director & TEG Board Member
P.S. Light Straw Clay is now an approved insulation material in the 2018 NEW MEXICO RESIDENTIAL ENERGY CONSERVATION CODE Residential Applications Manual at R1.48 per inch. More information can be found on page 27 of the manual here.
Santa Fe Community College Adobe Program Updates
The summer 2023 semester at SFCC has come to a close. The blended-learning Compressed Earth Block Construction class - led by CEB specialist John Jordan - spent a weekend on campus at SFCC covering the basics of the topic. We also offered the summer Adobe Practicum course with students completing field work at Cornerstones Community Partnerships, NM Earth Adobes, Albuquerque Joinery as well as Pecos National Historical Park.
The fall 2023 SFCC Adobe Construction class schedule can be found at:
Kurt Gardella - SFCC Adjunct Faculty & TEG Board Member
An Update on Recent Activities
at Adobe in Action
Twenty students just finished working their way through Adobe in Action's fourth online class of 2023 - Adobe Wall Construction. After completing a series of small lumber projects (rough bucks, gringo blocks and story poles), the students lay test blocks into a mud mortar to practice key adobe masonry techniques at home before heading out into the field.
Adobe in Action is celebrating its 12th year of offering online classes in 2023. The full 2023 class schedule can be found at https://www.adobeinaction.org/event-calender/. Our next online class - Roofs for Adobe Structures - started on Monday, August 14th but it is not too late to register.
In addition to our online classes, we continue to offer project support to four owner builders who have all completed our online adobe certificate and continue working on their home builds. An example Owner Builder Support Project can be found at https://www.adobeinaction.org/paul-mallory-project.
Kurt Gardella - Adobe in Action Executive Director & TEG Board Member
Earthen Legends
TEG has begun a project of compiling bios/stories of those people who have contributed to our industry over the years. We are interested in receiving bios from anyone who can add to our library of knowledge in a salute to those who make up the history of earthen construction. Send your submissions to theearthbuildersguild@gmail.com.
Criteria for submissions to Earthen Legends:
One whose profession was in the field of earthen construction – building homes, commercial buildings, adobe making, rammed earth, compressed earth blocks, scebs and manufacturing of materials and products used in earthen construction.
In the field of education – teaching earthen construction
Authors on the subject of earthen buildings/materials/architecture.
Architects, engineers, and designers of earthen construction.