Silver Seed Farms Straw Bale and Cob Building
Scroll down and read about
- Our Missouri hand-built straw bale octagon home
- Building with Bales: a Hands-On Workshop
- Cob and Earthen Ovens
- Natural plasters and finishes
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"The search for housing that is healthy, affordable and environmentally responsible is leading a growing number of people to take a fresh look at building techniques long-shunned by the modern construction industry. Earth, straw and bamboo, once materials of necessity by indigenous and pioneering peoples the world over, are now being rediscovered as materials of choice by those who are embracing an ethic of natural building." - Bruce A. Silverberg, Natural Building Colloquium Southwest |
How can we be Sustainable?We can be more sustainable by keeping a few things in mind. The Natural Building Colloquium Southwest says it best, "We can:
~ Minimize "embodied energy" - the amount of fuel used to process, transport, install and ultimately recycle what goes into buildings and products - by utilizing raw, local materials wherever possible. ~ Use simple construction techniques, easily learned, that require little skill and few tools. ~ Avoid the use of toxic substances, that might create health or environmental hazards during manufacture, construction, and habitation. ~ Minimize consumption of scarce, non-renewable resources by using alternative, renewable energy resources to the greatest extent possible. This is attained through the use of appropriate technologies on the one hand, ~ and by practicing a lifestyle of simplicity and conservation that is in harmony with the building and its environment." |
Building With Natural Materials
Building with straw and earth meets the standard for sustainability, with low-impact, non-toxic, low-embodied energy and the potential for using simple construction techniques. Straw is a waste by-product of wheat production, and using locally grown baled straw helps local farmers.
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To the left is the slideshow of our straw bale building process and homestead! Use the link above to get an explanation of each part of the process, and to comment. Our house is a bit unusual, in that it is an octagon-shaped, load-bearing house with "pods", built in 1994. In 2013, this house, with its straw walls and adobe floor, continues to stand the test of time.
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Read about our "Hands On" Straw Bale Building Intensive held
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Straw Bale Building Work Party held OCTOBER 19, 20 & 21, 2012 |
A Pattern Language of Natural Homes
A Pattern Language, by Alexander, is a collection of 253 things that make your living environment a pleasure.
A Pattern Language of Natural Homes is an introduction to a series of articles about many of the patterns where the organization illustrates them using homes and buildings made from natural materials like stone, clay, wood and straw. These materials are themselves one of the patterns, namely No.207 'Good (natural) Materials'. You will find links in each article to other patterns illustrated by the home and eventually, as with Alexander's book, to related patterns.
Octagon in Missouri
The Silver Seed, strawbale in Missouri.
Building possibly the first straw bale house in Missouri, we received a lot of questions. Have any ever been built here? How will it stay dry - isn't there just too much moisture and humidity in Missouri? Will mice get into the straw? What is an adobe floor, and how do you build it? We have also heard a time or two about the little pig who built his house of straw...
Building with straw is a curious thing, mainly because it had fallen out of favor in the last 100 years, before being favorably rediscovered 20 or so years ago. In America, native Americans built with whatever was around. Farming pioneers built with straw where it was available, just as desert ranchers built with adobe. All over the world, people have built with natural materials at hand, until transportation and mass production became the norm. Our world is starting to come to terms with the hidden costs of our current building methods, our ever-growing use of fossil fuels, and the wars over natural resources.
Missouri's moisture is a blessing - the reason for the forests, springs and rivers that make Missouri so beautiful. In terms of building a straw bale house with Missouri's moisture and humidity, there are examples of this kind of architecture all over the world, in many surprising places. There is a mansion, the Burritt Museum in Huntsville, Alabama, with a straw bale wall incorporated, there are straw bale houses in Canada and England, and the Burke homestead, a "Nebraska style" load-bearing straw bale house, is still standing in Nebraska since being built in 1903. It is the oldest known bale house still standing, though in disrepair. Since we built our house in 1994, there have been many more straw bale houses constructed in Missouri, some with great success.
There are some precautions one needs to take here in Missouri:
adequate eave overhang, a moisture barrier between the concrete foundation
and the straw wall, special care for second-story walls, and lots of planning before taking on your project.
Once the straw bale walls are covered on both sides, they are safe from moisture, mice, insects and fire. The walls do need to "breathe", so it is beneficial to use wall coverings that do not restrict that. We used cement stucco on our exterior walls and earth plaster and gypsum on our interior walls. However, after all this time, we would feel comfortable using something without the high-embodied energy of cement stucco, such as an earthen plaster. Additionally, due to the hygroscopic properties of clay, it appears the earth plaster would actually absorb any moisture that might make its way to the straw wall, absorbing then drying out.
After much research and experimentation with earth plasters and natural finishes, we would probably not use the gypsum plaster finish over the earthen plaster on the interior walls. While we love earth plastered walls, we wanted a very light color, for light reflection, which brought us to using the gypsum. Although convenient to use, the gypsum has a higher-embodied energy cost. It can be a local resource, depending on where you buy it. Drywall mud has synthetic additives but covers the wall easily. As an alternative, lime plaster can be used as a natural, lighter-colored wall finish over earth plaster. It covers walls easily, and it is wonderful to use with pigment, as a natural paint. Lime too, has higher embodied energy than simple earth plaster, but it remains a very good option in natural building.
In building our octagon-shaped straw bale house, we tried to use regionally available materials. The tools we used were very basic, and we built mostly with hand tools. We decided to use a mix of the old with the modern, low-tech and high-tech (solar power), along with our own unique interpretation of the materials and design. The beauty of strawbale and earth construction is the insulative and thermal mass value, the relative ease of construction, and the ways these natural materials allow you build intuitively and creatively.
Building with straw is a curious thing, mainly because it had fallen out of favor in the last 100 years, before being favorably rediscovered 20 or so years ago. In America, native Americans built with whatever was around. Farming pioneers built with straw where it was available, just as desert ranchers built with adobe. All over the world, people have built with natural materials at hand, until transportation and mass production became the norm. Our world is starting to come to terms with the hidden costs of our current building methods, our ever-growing use of fossil fuels, and the wars over natural resources.
Missouri's moisture is a blessing - the reason for the forests, springs and rivers that make Missouri so beautiful. In terms of building a straw bale house with Missouri's moisture and humidity, there are examples of this kind of architecture all over the world, in many surprising places. There is a mansion, the Burritt Museum in Huntsville, Alabama, with a straw bale wall incorporated, there are straw bale houses in Canada and England, and the Burke homestead, a "Nebraska style" load-bearing straw bale house, is still standing in Nebraska since being built in 1903. It is the oldest known bale house still standing, though in disrepair. Since we built our house in 1994, there have been many more straw bale houses constructed in Missouri, some with great success.
There are some precautions one needs to take here in Missouri:
adequate eave overhang, a moisture barrier between the concrete foundation
and the straw wall, special care for second-story walls, and lots of planning before taking on your project.
Once the straw bale walls are covered on both sides, they are safe from moisture, mice, insects and fire. The walls do need to "breathe", so it is beneficial to use wall coverings that do not restrict that. We used cement stucco on our exterior walls and earth plaster and gypsum on our interior walls. However, after all this time, we would feel comfortable using something without the high-embodied energy of cement stucco, such as an earthen plaster. Additionally, due to the hygroscopic properties of clay, it appears the earth plaster would actually absorb any moisture that might make its way to the straw wall, absorbing then drying out.
After much research and experimentation with earth plasters and natural finishes, we would probably not use the gypsum plaster finish over the earthen plaster on the interior walls. While we love earth plastered walls, we wanted a very light color, for light reflection, which brought us to using the gypsum. Although convenient to use, the gypsum has a higher-embodied energy cost. It can be a local resource, depending on where you buy it. Drywall mud has synthetic additives but covers the wall easily. As an alternative, lime plaster can be used as a natural, lighter-colored wall finish over earth plaster. It covers walls easily, and it is wonderful to use with pigment, as a natural paint. Lime too, has higher embodied energy than simple earth plaster, but it remains a very good option in natural building.
In building our octagon-shaped straw bale house, we tried to use regionally available materials. The tools we used were very basic, and we built mostly with hand tools. We decided to use a mix of the old with the modern, low-tech and high-tech (solar power), along with our own unique interpretation of the materials and design. The beauty of strawbale and earth construction is the insulative and thermal mass value, the relative ease of construction, and the ways these natural materials allow you build intuitively and creatively.
Contact us at silverseedfarms@gmail.com and let us know of your interest in our next straw bale building adventure or to let us know if you would like for us to lead a workshop at your place.
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Building With Bales: A Straw Bale Work Party! October 19, 20 & 21, 2012 The work party went wonderfully, with so much fun, fellowship and progress! Friends of the Snyder family helped them all the way, and we were in on the planning, designing, straw bale building and some plastering phases. This is a straw bale in-fill house. To use straw bales as "in-fill" means to first build the foundation, framing and roof, then to use straw bales as insulation and walls. |
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Building With Bales: A Straw Bale Intensive
October 2010 Workshop
This hands-on workshop consisted of building a load-bearing straw bale 13' x 15' building (la Casita), including discussion about and working with the earth bag foundation, cutting and re-tying bales, building bale walls, constructing the wall cap and basic shed roof, and some earth plastering and cob. We all had a lot of fun and gave it our best for three full days. Wonderful vegetarian lunches and beautiful weather were included. :-)
Earth Bag Construction
An extremely intriguing building method, earth bag construction is natural, sustainable, and accessible to anyone and just about any location. This is the method we worked with, combined with straw bale, for our October 2010 workshop. In the earth bag/straw bale Casita, we used gravel in the bags as the floating foundation on a trench of rubble over a French drain. In the final courses, we used earth-filled bags, then straw bales for the walls. The bags must be covered pretty quickly (we used cement stucco), as the Sun's UV rays will disintegrate them! Used as gravel bags, they are a lot of work, but they are a good, cheap alternative to pouring a concrete foundation.
In this midwest region of the United States, finding sustainable local fill for the bags that is insulative (lava rock, perlite) is a bit of a challenge. Earth and rock are great for thermal mass (absorbing and releasing heat), but they do not insulate.
Earth bags and cob can work beautifully here in Missouri for earthen/cob ovens, shelving, benches, foyers and a thermal mass wall.
Earth bag architecture is so beautiful. We recommend checking out the Cal-Earth website to see what projects they have been working on world-wide.
An extremely intriguing building method, earth bag construction is natural, sustainable, and accessible to anyone and just about any location. This is the method we worked with, combined with straw bale, for our October 2010 workshop. In the earth bag/straw bale Casita, we used gravel in the bags as the floating foundation on a trench of rubble over a French drain. In the final courses, we used earth-filled bags, then straw bales for the walls. The bags must be covered pretty quickly (we used cement stucco), as the Sun's UV rays will disintegrate them! Used as gravel bags, they are a lot of work, but they are a good, cheap alternative to pouring a concrete foundation.
In this midwest region of the United States, finding sustainable local fill for the bags that is insulative (lava rock, perlite) is a bit of a challenge. Earth and rock are great for thermal mass (absorbing and releasing heat), but they do not insulate.
Earth bags and cob can work beautifully here in Missouri for earthen/cob ovens, shelving, benches, foyers and a thermal mass wall.
Earth bag architecture is so beautiful. We recommend checking out the Cal-Earth website to see what projects they have been working on world-wide.
Cob
The right mix of earth, sand, straw and water, the uses of cob are many and varied, only limited by the imagination!
Cob Earthen Oven
A cob oven is a traditional earthen oven, a technique older than masonry, which is thick enough to hold a lot of heat (thermal mass). These ovens reach to around 800 degrees. The bread, pizza and pudding that comes from a cob oven is fabulous.
What is Cob?
Alex is appreciative of cob!
Cob is a mixture of clay soil, sand, straw and water. The sand/soil mix is fairly particular, so that it holds together well. "Cob" is a term used to describe the ingredients as well as the method of rolling and forming it into loaves or balls. Each loaf or ball is tied into the other with fingertips or a cobber's thumb. Rows of cob are built upon each other, as you sculpt.
The oven is generally formed onto a foundation, but foundations can be simple or complex, time-consuming or speedily accomplished. Foundations can be rock, brick, chunks of concrete rubble or even sawhorses!
Friends Inspire
Our friends, Angie and Paul, built a beautiful oven. It turned out to be a very fine oven, doing what ovens do best - cooking fantastic food, and it's a sweet sculpture, as well. Look closely at Froggy - he's really smokin'! He has a roof now, for his protection.
We were so impressed by the simplicity and beauty and deliciousness of the cob oven, that we started one of our own! I wanted to use as much material as possible from the land. This oven cost about $100 in materials, with the cost of sand, volcanic rock, and firebrick factored in.
Process of Creating a Cob Oven
Cob Oven Foundation
Our foundation is comprised of rocks and boulders formed into a dry-stack circular wall filled with smaller rock and gravel, all hand-gathered from our land and creek bed. All rocks were worked with so as to fit well together. I knew the size of oven I wanted, so all measurements were made accordingly.
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 Rock pile accumulates in rock-gathering expedition. WARNING: To build the way we did required tons of material (literally!). |
Sand and Firebrick
The top 4" of the foundation wall is filled with sand. Sand is not a good insulator, which is why I wanted to use the volcanic rock. Now the firebrick is ready to be set in! Firebrick withstands the super high heat of an oven, so regular brick is not recommended. I used a cob mixture between the rocks, just to fill in the gaps in the dry-stack wall. I would like to re-use bottles laid on their sides for insulating the foundation in the next cob oven model, slightly more experimental but cheaper to build.
Foundation Filler and Insulation
To fill in the rock foundation, we used bits of concrete and small rocks from all around us. Rocks seem to grow out of the ground here, after a rain! I also used cob to fill in between the large rocks on the inside of the wall, to keep smaller rocks from falling out. Once filled-in up to about 10" from the top, I added about 6" of volcanic rock for insulation. Insulation near the top of the foundation will keep the heat in the oven and away from being absorbed into the cold rock.
Natural Plasters and Finishes
Re-Finishing a Straw Bale Wall
The straw bale wall featured was an exterior wall, prior to the addition of the front entrance room. The cement stucco used on the exterior of the house is much too rough and unpleasant for an interior wall, so we decided to apply earth plaster over it. In addition, I wanted to make milk paint colored with natural pigment to use on the windowsill. When the project is completed, I will paint the earthen wall
with the glauconite (green mineral) milk paint.
The pictures below illustrate our process.
Click once to see an enlarged view of the picture.
 Drying good dirt in the sun. Snow makes dirt wet. |
 Cooking Dirt! |
We started this project in the winter of 09-10, and it was a cold, snowy week in Missouri. We had to collect our dirt, which we had already sampled to be sure it had the right breakdown of materials, and due to the wet and frozen nature of the dirt, we had to "cook" the dirt over the woodstove just to dry it out for screening and usage!
Where we removed the window and also where we joined the stucco-covered straw bale wall to the ceiling of the new room, we had to clean-up the edges and lay metal (stucco) lathe to join the unmatching edges and stuff the gaps with mud.
 Exterior window turned interior. Pulled the window out, and this is what was left.  |
 Packing mud under the metal stucco lathe, to fill in the gaps.  |
Once the lathe was covered in a first layer of tacky mud plaster,
we then covered the rest of the stucco wall. These pictures show only the
first layer, as the next layer is still to come!
 Earthen Plaster over metal lathe smoothes out window box area.  |
 Earthen Plaster, first layer  Hobbes on tile floor next to earthen plaster wall, 1st coat. :) |
The process of making milk paint was a lot of fun, starting with the quark and ending with that creamy, beautiful paint. I would like to find a local source for some of these beautiful colors.
 The milk is curdling.  Quark! |
 Making milk paint with quark, lime/water, and mineral pigment (glauconite)/water.  Milk Paint! |
One of the pictures below shows the windowsill covered in wheat paste plaster, used for texture and "evening-out" the old, recycled lumber we used. You can use wheat paste on just about anything. I am experimenting with different colors - inherent in spices, coffee, etc.
Our daughter said, "so....you're painting our walls with food...."
In a word, yes. :)
 Wheat paste drying on the windowsill.  Door frame with natural milk paint, 2 coats, over unfinished wood. You can still see the grain! |
 Sill with milk paint, 2 coats, wheat paste plaster underneath  Windowsill painted with natural milk paint colored with the mineral glauconite, 2 coats |
Check back, because we are always in the process of plastering, cobbing,
sculpting, and "finishing" projects .
Any questions, you may contact me at silverseedfarmslorian@gmail.com
Happy Plastering!
sculpting, and "finishing" projects .
Any questions, you may contact me at silverseedfarmslorian@gmail.com
Happy Plastering!
