Image Credit: Eva Wimmer Olinka finishes an adobe wall. Olinka is a student at Las Mujeres Constructoras and is learning about adobe mejorado and other natural building techniques, as well as carpentry and welding.
Image Credit: Liz Johndrow Installing bamboo wattle for a wattle-and-daub wall. These two women were participants in the two-week workshop to build the ‘‘natural classroom’’ at La Montana Solar.
Image Credit: Liz Johndrow Construction of the ‘‘natural classroom’’ at La Montana Solar. [Photo credit: April Magill]
Image Credit: April Magill Bamboo wattle at the ‘‘natural classroom’’ at La Montana Solar. [Photo credit: April Magill]
Image Credit: April Magill Teresa is applying daub to bamboo wattle. Vulgaris bamboo is susceptable to insects and the elements, but once encased in clay plaster, it acts as a the skeleton for this wall structure. Teresa is a grandmother who wants to teach her grandchildren these techniques, so they can build with the materials available to them in the pueblo. [Photo credit: Eva Wimmer]
Image Credit: Eva Wimmer Daubing the wattle. Workshop participants came from three different cooperatives to learn and build together.
Image Credit: Liz Johndrow Nancy Bernstein, a carpenter and timber-framer from New York, daubing the wall of the the first composting toilet in Sabana Grande.
Image Credit: Liz Johndrow The completed composting toilet. [Photo credit: April Magill]
Image Credit: April Magill Las Mujeres Solares and a solar oven.
Image Credit: Liz Johndrow Screening clay soil. [Photo credit: April Magill]
Image Credit: April Magill Aliosca and Nemia demonstrate the best way to make cob: with your bare feet.
Image Credit: Liz Johndrow A taquezal wall (a wattle and cob wall built with rice straw).
Image Credit: Liz Johndrow A taquezal wall. [Photo credit: Eva Wimmer]
Image Credit: Eva Wimmer Making adobe mejorado in Condega. Liz Johndrow is on the right. The trench foundation for the Learning Center was filled with stones and suelo cemento.
Image Credit: Liz Johndrow Four of the women who helped build the Learning Center at Sabana Grande. [Photo credit: Eva Wimmer]
Image Credit: Eva Wimmer Working on the final course of the Learning Center's adobe wall. [Photo credit: Eva Wimmer]
Image Credit: Eva Wimmer The Learning Center (or "natural classroom) in Sabana Grande. The benches are made of adobe. April Magill, one of the volunteers at Sabana Grande. April is an architect and builder from James Island, Charleston, South Carolina.
Image Credit: Liz Johndrow Eva Wimmer, one of the volunteers at Sabana Grande. Eva is a builder, photographer, and a member of the TreeYo teaching team.
Image Credit: Liz Johndrow The author, Liz Johndrow. [Photo credit: Eva Wimmer]
Image Credit: Eva Wimmer
[Editor’s note: Liz Johndrow is a natural builder who specializes in the use of cob, strawbale, adobe, earthbag, and earthen plasters. During the winter months, she volunteers in Nicaragua, where she works with villagers, especially women, on construction projects in Sabana Grande, Totgalpa. What follows is a sample of Johndrow’s blog entries written from Nicaragua. You can learn more about her work at her website, Earthen Endeavors.]
November 5, 2011. I am currently living in Sabana Grande, which is a community of Totgalpa. Both would be missed in the blink of an eye. Sabana Grande is known for its renewable energy initiatives and vision towards sustainable practices. Not everyone here participates in this vision, but there is a group, Las Mujeres Solares, which has a significant presence. Their focus is building and selling solar cookers, teaching renewable energy, and opening the Solar Restaurant for the volunteers and people passing through on the PanAm Highway 1.
Another group has formed with more of an agricultural and reforesting focus, Promoter Solares Agro EcologicÃ¡. Their stewardship is La MontaÃ±a Solar (Solar Mountain), and this is where my main building work will be focused.
November 5, 2011. Ninety percent of the cooking here is done over fires, and cooking beans in particular uses large amounts of wood. One of the the current projects at Solar Mountain was created by a university in Sweden, Chalmers School of Entrepreneurship, designing an initiative to reduce deforestation and poverty and to increase water supply. One of the first strategies implemented was using solar cookers, building more efficient wood-burning cookers, and creating a community kitchen where people can buy tortillas and beans with local currency, with the intent to cut the wood use in the community by 50%.
The next step is to improve the watershed. The Solar Mountain group is planting trees on the ravaged hillsides and building dikes to slow down the water flow. They have planted 14,000 trees, and have funding and a goal of planting a total of 25,000.
The public schools are limited in what they can offer within the very low funding for public education in this country. What I have seen so far is quite heartbreaking. Most schools don’t even have books.
Transportation consists of walking and riding bicycles, horses and buses. Bicycles are abundant. Not everyone has one, but it’s the equivalent of a car here and sometimes a truck! There is usually a sister, brother, child or mother sitting on the top tube or handlebars, sometimes two. Or I’ll see a young man riding, while balancing a a pile of wood on his shoulders and a 5-gallon bucket of water on each handlebar, or 50-pound bag of corn resting on the top tube. And I thought I had decent biking skills. Really, it’s impressive.
Solar headlamps and wood cookers
November 19, 2011. It’s been quite a few years of volunteers coming from all over the world to work on renewable energy and agricultural initiatives. Right now there are seven of us gringos from the U.S., Canada, and Switzerland.
Nancy and I are working on the natural building projects. Amanda is designing a solar headlamp for health workers that can be made inexpensively and repaired easily. Mike is building Ecofogons all over Sabana Grande. It is a highly efficient wood cooker and also creates less smoke, since it has a stovepipe. It is designed to cut down on wood use and smoke and was designed by the folks at Aprovecho Institute.
Fred is working on a “light in a bottle” design to use plastic bottles fllled with water to work as a prism, to bring in light into a building through the ceiling during the day. Julian is improving the autoclave solar cooker for sterilizing hospital equipment. Meanwhile we are all excited for the long-awaited grand opening of the Las Mujeres Solares restaurant in December.
Building a composting toilet
November 20, 2011. I am working on two building projects here in Sabana Grande, along with Nancy Bernstein, a carpenter and timber-framer from New York.
Our first project is a double-chamber composting toilet (see images #8 and #9, below). It is the only one in the village. Everyone here has basic pit toilets (la letrina) in the yard, though the solar restaurant received grant money to install a biodigester to their toilet and it makes gas they use for cooking at the restaurant. My Sabana Grande family also has a biodigester that they regularly feed cow manure for their cooking gas but it isn’t hooked up to the human waste stream.
We are using the toilet building project to try out a few techniques with the local materials from the mountain. We have excellent soil and red, yellow, and white clay in abundance.
There is also bamboo that is fine to split for wattle-and-daub, and lots of grasses and pine needles, as well as a parasite plant that grows in the trees and on the wires, that are a good source of fibers for adobe and cob.
Meanwhile, we are designing the classroom/gathering space for Solar Mountain. This includes learning as much as we can about bamboo for the structural aspect of the building, due to the lack of wood here.
This area is steeped in traditional building techniques. This won’t change much. This area is so impoverished; the people are poor and the land has suffered. It will take a long time to bring back timber and correct the erosion issues. Meanwhile people still burn wood for cooking everyday.
Dirt is still dirt cheap. Adobe works well and the people here know it.
Taquezal and adobe walls
November 20, 2011. Last month we went to Ocotal to see a 150-year-old building built in the traditional style called taquezal. It is basically a double-lath system infilled with cob.
Part of the inner wall was intentionally exposed in the restaurant we went to, and so we sat at the table next to the exposed wall, over a plate of frijoles and tostones and queso, translating the description to English.
Most houses here are adobe. The exterior is usually exposed adobe, or it might have a lime coat. A few people have put on a coat of cement stucco, but most people don’t think it’s a good idea. (I’m glad to hear this). The interiors are either lime-coated or have a simple paint (clay and water) of tierra blanco, some of the white clay from the mountains. Most floors are earthen, tile or cement.
This morning I stopped by the house of one of the Solar Women, and she was sprucing up her kitchen floor with a bucket of red earth, rubbing it in with her bare hands. Today was her daughter’s quinceÃ±era, so lots of guests were coming to her home and she was beautifying her kitchen. I would love to offer to put in an oil-hardened earthen floor, but I don’t imagine she would leave her kitchen for even a day or have the money for the oil.
While walking to the river to cut some bamboo, we met Maximo, who makes adobe bricks and here he is showing us the roof tiles he makes with 1/8-inch screened clay, sand, and sawdust. He puts them in a fire and they come out very durable ceramic tile for the roofs. We plan to use some for the entrance roof of our classroom.
Making plaster from local materials
December 4, 2011. Last week I spent some time at the Inanitah Community, on the beautiful island of Ometepe, teaching a small plaster workshop. Besides being an incredibly restful time in astounding beauty and getting a really good dose of organic fruits and vegetables, there was an excellent exchange of plaster and earthen floor sampling.
While I was “teaching,” I learned some more local traditional uses of various materials. First, they have a lot of volcanic soils on the island with two volcanos, so making something a pretty color is a bit challenging. The sand there is gray and black.
Also, the lime in the country seems to be questionable in freshness, chemical composition, and processing technique. So most people aren’t very excited about it. It tends to be chalky and weak, but we did add some pitahaya, a cactus that we soaked in water until it became slimy, and it appeared to improve the strength and chalkiness of the lime plaster significantly. Paul also mentioned a tree bark as an additive as well, but didn’t know the name of the tree.
When I returned to Sabana Grande, I mentioned the cactus and the tree bark to the two men, Don Lisandro and Hilario, who do a lot of the concrete foundation work around here. Well, they got very excited and animated, and of course starting talking muy rapido until I raised my hands to make it clear nothing was getting in. They laughed and started over, telling me about la cascara del guasimo, the bark of a tree that grows in abundance right here on Solar Mountain!
So yesterday we harvested and soaked some pitahaya and some guasimo, and I learned that the seed is sweet and is common refresco that they drink here. The seed is called tigÃ¼ilote.
Tomorrow I will make plaster samples with both additives for comparison. Don Lisandro also taught me how to make a lime paint with the guasimo and I am excited to try that for exterior plaster protection. He also has worked with lime plasters at El Centro Solar on their adobe buildings, so I will stick close to him as we finish our plasters on el aulo, the learning center we are building.
And the soil here is very nice to work with as well. It is strong and muy pegajoso, which is music to our ears. Yep, it’s very sticky stuff and makes a very strong plaster. Can’t wait to add the manure and slimy plant stuff and see what we get!
“Dirt” houses carry a social stigma
December 4, 2011. I’m happy to see there is a strong desire on the part of some very dedicated Nicaraguan architects and builders to re-emerge traditional techniques and encourage sustainable, healthy, and affordable building for Nicaraguans. They are working to nip that “concrete is better” belief in the bud, and support a return to earthen architecture mentality.
Many of us are aware of the class issue and mentality that exists in the world in places where living in “dirt” houses is a sign of poverty even when these clearly, when well-built (like any material and modality needs to be) surpass concrete in function, environmental impact, and even beauty. Some of the international efforts are less dedicated to this understanding and continue to bring in volunteer teams to build with concrete. These are often young people paying to have a cultural “gap year” experience in a service project, and to have an opportunity to practice their Spanish.
And of course there are many builders here who are building with concrete within the country as well.
I recently attended a seminar in Granada, Construccion social y recursos naturales, that was sponsored by an organization from France that has a long-term project and relationship with an organization in Granada, La Casa de la Mujer. The seminar sponsor group, CRAterre, has a focus of earthen architecture and is working on education and resources for the women’s organization regarding their choice of building material.
The day-long seminar was with architects, engineers, builders, and local women in the social justice movement. I listened to presenters stories for hours, while practicing my Spanish and helping others practice their English! And there were several presentations about adobe, bamboo, rhino block, and tequezal.
Of course I missed much because it is still difficult to process that much Spanish and when people are passionate they speak quickly! But the visual presentations and having context were a fantastic help and I managed to clarify a lot by cornering people at breaks and meal time.
Bamboo vs. wood
December 4, 2011. Since I got back to Sabana Grande a couple of days ago, the Grupo Fenix team of Nancy, Susan, Erika and myself have been spending hours and hours discussing bamboo vs. wood. We try to look at the social, economic, and environmental issues involved in each material, weighing out all the pros and cons that we can think to raise within the debate.
With wood, there is a severe crisis in this country. For several decades it wasn’t managed at all and the serious deforestation leaves little wood to harvest. A few years ago a moratorium was put on wood harvesting and it was extremely difficult to even buy wood for construction. Now it is easier and supposedly the harvesting regulations encourage responsible actions, but it’s a poor country and with it comes lots of corruption, so we just don’t know how responsibly harvested. Still, wood is relatively inexpensive to buy so it is most likely what the locals can afford from pocket. And we love wood and we know wood.
Bamboo, on the other hand, is not yet here in abundance and is just beginning to be grown and harvested in Nicaragua. Yet it is a highly renewable material, thriving on proper harvest strategies, and as I understand, in five years an acre of land could be producing enough bamboo annually for a dozen homes.
This could be a huge boon to the agricultural community here on Solar Mountain. But in the short run bamboo costs two to three times what the wood would cost, which is significant cost to the people in this region. The cost seems to come from the necessary curing and drying process.
So we have proposed to the bamboo farmer that he deliver the bamboo and give us a two-day workshop in reforestation, harvesting and curing techniques, and building and joint techniques. This way we can feel that we are making a solid investment in a more responsible building material that would actually reach and truly benefit the community of Sabana Grande in time.
Designing an earthen building
January 20, 2013. I will never handle a machete as well as any of these women, and do such a diverse number of tasks with one simple tool. And their mastery of making a tortilla is a beautiful thing that easily translates to other creations with their hands and rhythm. So it was an exciting two weeks, because I pretty quickly saw these goals being reached.
They were a playful and affectionate group though some are shy and lack confidence and need more coaxing. But they all know how to work, so if they were given a task that they were comfortable with and it loosened them up, they often they stepped up to something else they hadn’t tried before.
Originally they shared their vision as a group, and Nancy and I took their ideas and designed a space that could fit the needs of the group, accomplishing most of it in a two-week workshop and working with a small budget from some appreciated monetary donations.
The original design incorporated bamboo as the framing component, but that was washed away in a Christmas Eve flash flood, and the supplier didn’t get another cutting to us in time. So we went ahead and used local wood, though we tried to use a minimal amount since it is pretty scarce.
Checking out local construction methods
January 31, 2012. On a recent bus trip, I enjoyed observing the use of local resources in their building techniques. I always enjoy being in a place that is still in touch with using the natural resources inherent to the building site area and has traditional building techniques still being employed.
Most people are quite happy with the sensibilities of using the resources available to them, particularly with the scarcity of money for purchasing materials. There is the use of concrete as a smooth and easier-to-clean surface compared to the commonly seen dirt floors and more crumbly adobe walls. I continue to observe and inquire as to what prevents them from taking the surfaces a step further, towards what I would define as finished.
I have also noticed that many people don’t fully understand the needs of lime as a plaster, and so it often fails here. In areas where there are purer clays and people have sufficient overhangs, there are lovely, simple clay finishes on the exterior and interior.
Of course these clay paints and plasters bond beautifully with the adobe. But there isn’t always sufficient keying with the adobe when they use lime, and my observations suggest that there isn’t very good bond, so I suspect the adobe isn’t sufficiently hydrated before application and there is also little done to keep the lime protected from the sun and wind and sufficiently hydrated those first days after application. I am in the middle of doing some tests and creating a more durable lime plaster and I am testing it on the composting toilet in Sabana Grande.
Local women build solar ovens
January 8, 2012. The Solar Women have just opened their restaurant! It’s been a big step for them to opened their doors and invite in the public. It’s a lovely adobe building that they built two years ago, and it is exciting to see the bustle of activity finally happening there.
Meanwhile, they have recently received an order for 20 cocinas solares (solar cookers) to go to a community in Chinendega, so I was able to see them working on the cookers this morning. Maria Magdelena, a student at Las Mujeres Constructoras, does a lot of the carpentry. They all participate in painting, fastening hinges, placing the glass and such. Some of it’s very particular work, so the women who have shown particular finesse in these different steps of the process now build the cookers and take great pride in their business.
February 27, 2012. For the residents here, a lot of time is spent taking care of the daily basic needs. Hauling water, hand washing clothes, gathering wood, tending cows, planting, tending and harvesting corn and beans and squash, and the many steps of preparing the corn for tortillas.
There is plenty of opportunity for social interaction as some of these chores are accomplished. Women often hang around the wells while filling buckets and washing clothes at the wash station provided. These clothes-washing stations allow them to haul less water all the way back to their homes and everyone takes turns cleaning the well area.
Building a classroom and youth center
January 20, 2013. Sabana Grande is a pueblo of Totogalpa, about 20 km from the Honduran border. This is the poorest region of Nicaragua, in the second poorest country in Latin America. Most everyone here lives well below poverty level.
The people are kind and care for their families and community and are excited, in this particular community, for the growing application of renewable resources. The renewables allow this very poor community to attain a higher quality of life while living within the limitations of their immediate environment.
We trained several women from the community to build with local natural resources in their raw form and they now have a ‘‘natural classroom,” which they are inspired by and proud of.
I choose to introduce many techniques and support their more indigenous knowledge of building with adobe. They refer to these new techniques as “modern natural building” and are proud to have built some natural and modern (and cheap!).
The gringos who show up are volunteers here to share and learn about renewable energy and live within the community for their time there. There are no showers or internet or cars and such.
The other group I am working with, Asociacion Mujeres Constructoras de Condega, is a women’s carpentry school in the town of Condega, serving young women from rural communities. These women train in non-traditional trades such as carpentry and woodworking, welding and residential electricity installation.
This year (2013) I will be leading a two-week workshop in which we will build a round adobe youth center. I have two women assistants, budding natural builders from the U.S. and Austria, to support the project and learn more about the culture and natural building. We will be joined again this year by the same team we trained last year and they will continue to learn the skills. We are using their traditional materials but introducing a round and sculptural building, that will support the youth in having a learning center.
At the site of their school we will be building a cocina and kioska for the school, providing a place to cook meals, eat, and study in a beautiful environment built by the students and community members. I will be teaching different techniques, along with my assistants and a maestro from the school, a 23-year-old engineering student Felipe, who is so excited to learn from me (and me from him!), support women in their empowerment and trades learning, and is a sweetheart of a guy!
A successful project, and good vibes
Feburary 3, 2013. For the first two weeks of the workshop we finished the adobe walls, put up posts and top beams, began five different wall systems out of bamboo, branches, clay soil, and straw. We have begun the adobe benches.
This week we will add in some bottle art and cob backings for the benches, bas-relief sculpting, earthen floor samples, basecoats and finish plasters.
The workshop has gone all too fast, even in this land of equatorial heat and tranquilo vibes. I am so glad to know I will see many of these women that I am quickly growing fond of, again at the next workshop in just two weeks. I’ll have a bit of a base of some new accidentally stumbled upon racy and vulgar phrases, a few more Nica songs under my belt to play on the guitar, and new relationships with some of the sweetest women.
Postscript: Reflecting on this year’s work
March 2013. It was wonderful to return to Sabana Grande for a second project this year.
Last year I was able to teach the communities different possibilities of cob, wattle and daub, variations on taquezal and wattle and cob, bottle art and sculptural techniques, using adobes for benches, earthen floor, and how to make clay and lime plasters that will last and be beautiful.
This time, after assessing the desired project, the site and location, and the financial resources, I decided that working primarily with adobe was a sound choice. It would allow the women to continue to work with the vernacular building style and make the bricks themselves. This would provide them with income for the two weeks of adobe brick making.
Also, the field where the youth center would be is a bit if a cooker, and the thick adobe walls would buffer the daytime heat. The thermal mass of the adobe stabilizes the rather intense daytime heat and keeps it cool until nighttime, when the temperatures drop again and draw the heat back out of the bricks.
Among the challenges I have seen with adobe (and ”modernizing” it with plasters) are poor preparation, proper hydration of the substrate, and insufficient understanding of how plasters work well. The people in this region never used to plaster the adobe, and then they jumped right to cement stuccos, which has proven to fail over and over. But they like the idea of smoother surfaces that are less rustic and less likely to provide housing for insects.
Since this is a youth center, we chose a circular shape to create a nice community meeting space, create some playful elements, and allow the curves in all directions to make for stronger plasters. On the other new adobe buildings there, most of the sharp 90 degree corners are already damaged and have lost their plaster.
We are softening all the edges on this round building and using our best recipe of red clay soil, river sand, screened horse manure or burril, fresh cow manure, and guasimo. It makes for a super-strong plaster that the kids can climb all over.
We began the project with leveling the site by hand. This is sun-baked earth that was hard as rock. It took hour after hour of work with a pick-ax and bar to break it up and carry it away in wheelbarrows. They continued digging for the meter deep by meter and half below grade foundation or cimiento. This took several dedicated people several days.
Once the trench was dug, it was time to build the stone and suelo cemento mortero foundation. The mortar is 6 parts clay-based soil and one part cement. This allows for the foundation to absorb the tectonic uplift forces through its flexibility from the earthen element. The proportion of stone to mortar is about 50%-50%.
We decided to continue the suelo cemento above grade for the stemwall or sobrecimiento. This isn’t recommended for its vulnerability, and often straight concrete is used, but we had so much success last year in using earthen mortar and covering between the stones with a thin cement mortar that we decided to do this again and minimize the concrete use in the building.
Once we finished the foundation, we were ready for the workshop to begin. We had one thousand adobe bricks, built to the standard for adobe mejorado, sized for seismic strength at 14x14x4 inches. Also several yards of river sand, several more yards of red clay-based soil, and dozens of bags of burril and rice straw.
We had sixteen courses of adobe to stack and two curvy cob walls to break up the interior space and continue outside to provide shade and places to play. The height of our walls was to be no more than 8 times the width of the bricks. This provides a more stable wall system.
We also introduced burlap strips in the mortar layer of the three middle courses (7-8-9) for additional tensile strength.
I will be returning in a few weeks to work on finish plasters, earthen floor, and a community art project as a sculptural mural on the outside wall. The folks there are putting on the tile roof, finishing the cob walls, and softening all the edges of the adobe for a more enduring plaster. Stay tuned!
Liz Johndrow lives in Putney, Vermont. She is a builder and trainer who offers workshops on natural building skills. Her website is Earthen Endeavors.
Get building science and energy efficiency advice, plus special offers, in your inbox.