TEG Newsletter - Issue #17
We have news for you!
Northern New Mexico Fire Response
from the Earthen Community
As I write this from Northern New Mexico (Taos, NM) we are in a crisis state – a natural disaster. Fires are raging through our beautiful land and historic small communities. People are responding with help in many ways as the disaster unfolds. We are looking forward to the recovery efforts that will take place over the next many months and years. Many homes in this area are adobe structures. A group of us in the earthen community met this morning to address possible future needs. Questions asked included: Can an adobe home withstand a fire and still be repairable? Who is available and qualified to evaluate the damaged homes? Will those whose adobe homes are destroyed be willing to rebuild with adobe?Are people willing to rebuild as owner builders? Who will evaluate the safety of these homes? Are materials available to those who do want to rebuild with adobes? Are there contractors willing and available to help rebuild with earthen construction? How do we connect with these rural communities and offer help? Who is interested in working on these issues? The questions are endless. The group this morning represented The Earthbuilders’ Guild, Adobe in Action and Cornerstones. If you are interested and willing to participate please indicate your interest and skill set by dropping an email to The Earthbuilders' Guild at email@example.com.
Pat Martinez Rutherford - TEG Board Member
Celebrate Historic Preservation Month by Making Adobes in Santa Fe
The Earthbuilders’ Guild will be joining Cornerstones as they host an adobe brickmaking event at San Miguel Chapel on Saturday, May 28th. Adobe Downtown will be an opportunity to participate in brickmaking and enjoy historic Santa Fe.
May is Historic Preservation Month, and the bricks we make together will be used to restore historic community buildings in Chimayo and Mora! We will have staff and volunteers ready to teach and supervise all who attend the event. All ages are welcome. Cornerstones will supply all materials. Brickmaking will start at 9 am and run through 2 pm. The Earthbuilders’ Guild members will be participating until noon. At which time we will be making our way to our bi-monthly Board meeting. If you are interested in attending the board meeting contact us at firstname.lastname@example.org or call Pat at 575-644-8099. We look forward to being a part of adobe making with Cornerstones. Come join us!
Pat Martinez Rutherford - TEG Board Member
International Code Council Hearings - Notable Developments
Every three years, the International Code Council solicits proposals from individuals, trade associations and professionals to change the International Building Code (IBC) and International Residential Codes (IRC) which in some form or another govern construction in most of the United States. In a three step process, these code proposals are debated, modified and approved or denied. The Committee Action Hearings, the first steps of the process, were recently held over ten days in Rochester, New York. A committee made up of subject matter experts hears testimony about each code change proposal and either recommends it for approval or disapproval. Here are the notable outcomes of those meetings:
Adobe Masonry - IBC 2109
A proposal by a trade group for the conventional masonry industry was successful in a first stage attempt to remove adobe masonry from the 2024 version of the International Building Code. The Masonry Alliance for Codes and Standards has for several code cycles been attempting to eliminate adobe from the I-codes as its design is not addressed within the masonry design standard (TMS 402) published by that group. They were successful in obtaining the Committee's initial approval which still needs to be ratified at the Public Comment hearings held this fall. The Earthbuilders' Guild will be submitting testimony in opposition to the removal, and will be providing guidance for members to do the same.
Crushed Stone Foundations - IRC 403
A proposal to allow and provide criteria for the use of crushed stone foundations was not recommended for approval by the committee.
Strawbale - IRC Appendix AS
Numerous improvements to the Strawbale appendix were proposed by California strawbale advocates and recommended for approval by the committee.
Cob (Monolithic Adobe - IRC Appendix AU
A proposal advanced by the authors of the original cob appendix was recommended for approval as submitted, including editorial improvements, clarification of window and door installation requirements, and R values for various cob densities.
Hemp-Lime - IRC Appendix AY
Proponents of hemp lime as an insulation and non-structural infill received the committee's recommendation to create a new appendix to the IRC to use hemp-lime (sometimes known as hempcrete) as a non-structural material. For earthbuilders, the recognition of hemp-lime within the code promises to add a new low-carbon, vapor permeable insulation system with R-values of up to 2.1 per inch to the other exterior wall insulation technologies (such as light straw clay and rigid insulation) already in use.
The public has an opportunity to comment in support or opposition of those recommendations in the second step. Public Comments on the above items and any other code change proposal can be made by anyone before June 20th by registering at CDPAccess.com and those comments are evaluated in the Public Comment Hearings which will be held this September in Louisville, Kentucky. Based on the outcomes of those two hearings, in October building officials will vote on the acceptance of those recommendations, with the final outcomes being recorded as revisions in the 2024 editions of the IBC and IRC.
A special thanks to Martin Hammer, Anthony Dente, David Eisenberg, David Arkin and everyone else who travelled to Rochester to represent the interests of the public and earthen and other sustainable building advocates.
Ben Loescher - TEG Board President
An Update on Recent Activities at Adobe in Action
Seventeen students just finished working their way through Adobe in Action's third online class of 2022 - History & Basics of Adobe Construction. After completing their midterm projects - collecting and testing local soil samples - the students made some test adobe blocks as part of their final projects.
Adobe in Action is celebrating its 11th year of offering a full online adobe certificate. The full 2022 class schedule can be found at https://www.adobeinaction.org/certificate-classes.
In addition to the online program, Adobe in Action is offering two live-instruction workshops this spring. The first workshop - Intro to Adobe Preservation with Pat Taylor - took place in Mesilla, NM on April 8 & 9. See some student photos of this workshop here:
The second workshop - Natural Plastering with Issac Logsdon - will be taking place in Santa Fe, NM on May 21 & 22. More info about this workshop can be found at:
In other news, Adobe in Action is continuing a special eight-part podcast miniseries dedicated to the topic of preserving earthen architecture. In this final episode of the miniseries - Mud Talks 15-8 - we speak to Jake Barrow, Cornerstones Community Partnerships Program Director. We speak about wood elements in earthen structures and their preservation as well as the importance of maintenance plans and cycles for earthen structures. Listen to the episode at:
Kurt Gardella - TEG Board Member
Santa Fe Community College
Adobe Program Updates
The spring 2022 semester at SFCC is coming to a close. The blended-learning Finish Practices class - led by natural plaster specialist Issac Logsdon - spent a weekend on campus at SFCC covering the basics of earthen plaster and then wrapped up the course with some field work at Capilla de San Pedro in Ohkay Owingeh, NM. See the group in action here:
The summer and fall 2022 SFCC Adobe Construction class schedules have been released and can be found at:
Kurt Gardella - TEG Board Member
BECOME PART OF THE ADOBE TRADITION
Hire on at New Mexico Earth Adobe for the 2022 season!
Making the story of adobe in New Mexico a part of your life means you are one of the few who can truthfully recount to everyone the joys of working in the sun making mud bricks, and who can baffle their friends with tales of their seasonal job making this iconic southwestern building material.
From those who have no idea: “You did what? What are those? I’ve never heard of that. Mud?? They build with those things?
Or perhaps they know all about adobe: “You did what? That is so cool!”
This is an opportunity to be involved in something very unique, and to contribute to the earthen building tradition in New Mexico. In addition, it’s a good starting place for someone desiring to learn more about adobe, with an aim towards moving into construction or design.
Hours are flexible, with full- and part-time options. Work lasts until October, possibly longer if the weather continues warm into the Fall.
Contact the office for information: 505-898-1271
SCEB Research at Sandia
National Laboratories (cont.)
This will be my next to last newsletter article regarding the SCEB testing projects at Sandia National Laboratories. All testing has now been completed and the final report on the ASTM E119 Fire resistance test results will be produced by the Sandia engineers and handed to us probably by the end of May of this year. It has been quite a mixed bag of results, a roller coaster of hopes and disappointments, worries and fantastic data, all over the place. In the next and final newsletter article I will summarize multiple aspects of this years-long testing and will attempt to give a full picture of the benefits that it has produced. That being said, I will move on to the results of this years’ main test, the fire resistance test. Spoiler alert, this year’s test failed once again. Why it failed is new though.
As described in my previous newsletters, the goal of this testing was to demonstrate that SCEBs can be bonded with epoxy and made capable of successfully passing the prescriptive requirements specified in the ASTM E119 testing regimen. In the two previous tests, in 2020 and 2021, the tests failed due to the inability of the Sandia fabricated burner apparatus to achieve the required temperature level of 1000°C, which needs to be held for a specified amount of time, in this case 4 hours. This burner structure was the first attempt by the Sandia engineers working on this project, and in many ways was an impressive achievement up to a point. The first year the temperature hit about 600°C and they could not get it to rise above that. They ran the test for the full 4 hours, but it was a technical failure nonetheless. The second year in 2021, they rebuilt components of the fuel supply line, etc., and once again ran the test, this time with even worse results, not rising above 550°C. Again, another technical failure of the test. So, late in 2021, they went back to the drawing board to really address the issue. They found an existing apparatus that performed to the specifications, although they had to replicate it rather than import it since it is located at another military testing facility out west. So, we entered this year with high hopes that the rebuilt apparatus would finally produce the temperatures needed to meet the requirements.
The test was conducted on Tuesday, April 19th. I visited the test site the day before to assess the state of the test wall, which was still in place from last year’s failed test. Since the wall had only been subjected to a low temperature (only 550°C, just a touch over 1000°F!) we believed that any damage was quite minor and that the wall was still capable of passing the test. The wall looked quite good, with some minor spalling damage on the wall face that had been hit with the required water spray after the heating. The engineers tested the various components of the new burner structure, tested the hydraulic subsystem that would supply the required weight on the wall during the burn test, and tested the water spray to ensure that it would meet the spec. All components were working correctly and therefore the test was carried out. As I was driving out to the test site on the morning of the test, I received a call from the lead engineer saying that the required temperature had been achieved but that part of the hydraulic system had failed. This meant that there wasn’t the required weight load on the wall as specified in the test regimen. This also meant that the test was once again a technical failure, not having met all the specs for the required amount of time.
The engineers had indeed rebuilt the burn apparatus, and it was impressive and quite ferocious. This new structure and fuel/flame system went from last years’ 500 gallon LP gas tank with a ½ inch feed line coming from the top of the tank (gaseous propane) that fed 16 burners, to a 1000 gallon LP tank with a 1.25 inch feed line coming from the bottom of the tank (liquid propane) that was feeding a massive 20 burner manifold. This new feed line had a simple ball valve control, along with various safety shut-offs, etc. Quite impressive in both looks and performance. The test specs say that the required temperature of 1000°C must be achieved within 30 minutes from the start of the burn and then hold for the remaining required time. The engineers said that the new burner achieved the required 1000°C in just under one minute! This was one serious burn apparatus, but now one problem was that the simple ball valve didn’t allow for fine tuning the temperature, and in fact the ball valve was only about ¼ open and the engineers were concerned that if the valve was closed even a fraction that the burner might lose enough gas to go out so they opted to leave it where it was. The temperature hit and maintained a relatively steady 1110°C (average reading) within just another few minutes and all seemed under control. After about 20 minutes the engineers noticed that there was a problem with the hydraulics and that one side showed a very low reading. They attempted to apply more pressure but within just a few seconds it was apparent that one side had completely failed and, while pumping the pressure up, the remaining hydraulic arm had actually caused the I-beam on the top of the wall to lift up in a cantilever manner. As they saw this happening, they realized that the whole hydraulic system could no longer be used, and they released the remaining side pressure. This caused the I-beam to thump back down onto the wall during the burn and for a moment it looked like the I-beam might topple off the wall. An 18 foot long, 12-inch-tall I-beam like this weighs upwards of 1500 pounds and this would have been both catastrophic and potentially quite dangerous. The beam stayed in place though and the burn was continued. It is not known at this time exactly why the hydraulics failed but they will do a post-mortem analysis to make that determination. The two previous tests had used the exact same configuration but the huge difference in temperature had subjected everything within the test facility to an enormously higher amount of heat energy, including the hydraulic subsystem. As true a stress test as could be imagined and this one subsystem was compromised causing the entire test to technically fail.
The following images show the test procedures and the wall before and after the test.
The “test article” wall, saved and essentially undamaged from the previous test in the fall of 2021. As can be seen, there is a vertical stripe running on the edge of the wall. This indicates how deeply the heat energy penetrated in the previous test, which appears to be roughly half-way through the blocks. The decision was made to proceed with the new test since the wall was deemed intact.
The new burner apparatus. The feed line (dark hose) is coiled up ready to be connected to the LP tank. There are thermocouples (TCs), nine on the inside of the burn box and nine affixed to the back surface of the test wall, to measure the heat within the box and also how much heat is passing through to the backside of the wall. The leads for the thermocouples are the silver coiled lines.
The new liquid propane (LP) 1000-gallon tank. This behemoth was quite the addition to the test hardware and allowed for a bottom feed of the actual liquid fuel rather than a top feed of gaseous fuel. The difference in the amount of energy (BTUs) between the two is what it took to get the required temperature. The engineers felt that this system could go well above the required temperature!
The test is underway. The blue arrow points to the red-hot burner manifold which has actually bowed under the intense heat. The red line circles the failed hydraulic component on the right side of the test wall. It is somewhat hard to see, but the upper I-beam is glowing red in the center from the top exhaust area of the burn box. The noise from this was incredible, sounding almost like a jet engine!
The test data was being continuously monitored and recorded. The upper set of lines (squiggly) are the TCs located inside of the burn box. The reason they are so rough is that cold air coming into the burn box can alter their readings instantaneously. The average though, comes in around 1100°C. The lower set of lines (smooth, mostly) are the TCs located on the back side of the wall. The two squiggly lines are thought to be caused by these TCs coming off the face of the wall, with the top one being exposed to the swirling hot air around the whole test area. The average temperature on the back side of the wall at this point in the test, approximately an hour half in, was around 65°C. At the time of the completed test, this had climbed to around 100°C. The U factor of earthen is on complete display in this small image!
The test is still underway, but now the phase is the water spray onto the wall, which had to happen within 5 minutes of the burners being turned off. It is a bit hard to make out, but the amount of steam roiling out of the facility was amazing! Keep in mind that the wall being sprayed is at least 20 feet in front of the fireman. There was a minor amount of spalling which was propelling small bits of aggregate out like BBs. This stopped within a couple of minutes, but the spray duration was a full 5 minutes per the test specifications. Upwards of 1200 gallons of water was used.
The test is now completed. This shows the test wall with the burn box out of the way to the right side. As can be seen, there is some intense scorching on the lower left side and also lower center. This is where some of the burner box point flames were almost directly hitting the wall, causing a disproportionate amount of heat to be focused there. No real damage to note, even where the I-beam had lifted up on the very upper left-hand corner when the hydraulics failed. In our opinion, there is no doubt that this test would have succeeded had the hydraulics not failed. John Jordan - TEG Board Member
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 email@example.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.