Index

Adams, Lynn Elizabeth and Cassandra, 35 additions, designing for, 108 adobe architecture, vs. earthbag building, 5-6, 8 Adobe Builder Inter-Americas, The (Tibbets), 111 Adobe Journal, The (Moquin), 1 Adobe Story, The (McHenry), 57 advantages (of earthbag building) built-in stabilizer, 9 cost effectiveness, 9-10 employing people, 10-11 environmental, 4 flood control, 8-9 simplicity, 4 sustainablility, 11 temperature control, 9 tensile strength, 8 vs. other earth-building methods, 4-8 alis (clay...

Designing Post and Beam

One of the most common strategies for getting a building permit in areas where earthen architecture is unfamiliar, or officials are heavily biased against it (usually from ignorance of the medium), is to incorporate a post and beam framework as the load-bearing structure, delegating the bag work as infill. This is contrary, of course, to all one's efforts directed at minimizing the use of lumber and energy intensive materials like cement and steel. At least it may help you get a house built,...

The Gothic Arch

The second type of classical arch we will address is called the Egyptian or, more recently, Gothic arch. In the 1200s, Abbot Suger, of the Abbey of St. Denis outside of Paris, had a plan for transforming the squat, heavy Romanesque style into an architectural wonder of the time. This is a steeper-sided arch than the hemispherical shape of the Roman arch. While the same forces of compression and tension are at work on both arches, we will soon see how the steepness of the Gothic arch directs the...

Roof Systems

There are a zillion styles and methods of building a roof, many of which can be adapted to sit on earthbag walls. Our job is to show some techniques with which to anchor the roof to the walls and share roof styles that we feel complement the earthbag system. We are big fans of Native American architecture as well as vernacular architecture worldwide. All we need to do is look at how indigenous peoples built their homes to suit their environments to see what design features we, too, would find...

Designing for Your Climate

Bentley Chudleigh

The book Alternative Construction, by Lynne Elizabeth and Cassandra Adams, offers case scenarios for six different climate zones and which hybrid combinations of mass and insulation suit each climate. An expert can customize the appropriate proportion of insulation to mass, but by looking at nature and the 17.1 Shade is a priority in a hot, sunny locale, and extends the living space outdoors. Natural interior climate control of a building is an art and a science that takes in a variety of...

Plumbing

As with the electrical system, have a plumbing design plan figured out before the walls are started. Incoming water and outgoing drains will likely come in under the foundation or through the stem wall, depending on frost level and the type of waste management system. The plumbing arrangements for an earthbag wall are pretty much the same as they would be for any other type of construction method. Horizontal pipes can be laid in between the surface of the rows of bags and cinched tight with the...

Velcro Plates

Doorjambs, shelf attachments, electrical boxes, intersecting stud frame walls, lintels, rafters, and extended eaves for domes, all need to attach to something that anchors them into an earthbag wall. Velcro plates are simply a flat wooden plate from one-half to one-inch (1.25-2.5 cm) in thickness, about twelve to sixteen inches (30-40 cm) long, cut to the approximate width of the wall and nailed into the bags. A strip anchor (a term used in adobe construction) allows for the later attachment of...

Shingled Dome with Extended Eaves

We have yet to try it on a full-scale dome project, but we've collected loads of free asphalt shingles and hammered them into the mud-plastered surface of the Honey House dome. They are easy to anchor, and stagger to conform to the curve of the roof. They can be installed very thickly with an overlap of one inch (2.5 cm) or less creating a thick, thatched appearance. Earthbag domes can carry a substantial load. With shingles set this thick they could last a lifetime, and we may have developed...

Cut Barbed Wire Not Trees

We have the ability to build curvaceous, sensual architecture inspired by nature's artistic freedom while providing profound structural integrity. Earthbag construction enables the design of monolithic architecture using natural earth as the primary structural element. By monolithic architecture we mean that an entire structure can be built from foundation and walls to roof using the same materials and methods throughout. Corbelled earthbag domes foster the ultimate experience in sculptural...

Round Is Sound

As far as using earthbags as an alternative foundation system to conventional concrete, we have one very strong recommendation to make. Build round when you build underground. Bermed and buried walls undergo tremendous stress from the surrounding earth as the walls are backfilled as well as over time as the world settles in around them. When the earth exerts pressure onto the walls of a round structure, the compression is equally distributed throughout the full circle (Fig. 4.17). The same...

Roofing Options for Domes

The exceptional strength of a corbelled rammed earth dome can easily be designed to carry the weight of a nine-inch (22.5 cm) thick living thatch roof (we've done it ) or a hefty layer of sculpted adobe. Traditional thatch, terra cotta tiles, lime plaster over adobe, mortared slab stone, slate, wood, and even asphalt shingles (a good, cured rammed earth will hold long roofing nails), are also suitable roofing materials. For insulating a corbelled dome in a cold climate, we have designed a wood...

Can Tossing

As the walls grow taller, we toss the cans of dirt up to our partner on the wall or scaffolding. This may sound like an uncomfortable or awkward way to get the dirt up onto a wall, but compared to lifting a 100- or 200-pound (45-90 kg) bag onto the wall, an eight-pound can of dirt is beautiful in its simplicity. In fact, it's more like a cooperative non-competitive sport. 3.8 The large restaurant-size tomato can, coffee can, etc., 3.8 The large restaurant-size tomato can, coffee can, etc., If...

Empowering Community

Earthbag construction utilizing the Flexible-Form Rammed Earth (FFRE) technique employs people instead of products (Fig. 1.10). The FFRE technique practices third world ingenuity, with an abundance of naturally occurring earth, coupled with a few high tech materials to result in a relatively low impact and 1.11 Typical 1,000-year-old Anasazi structure, Hovenweep National Monument. 1.11 Typical 1,000-year-old Anasazi structure, Hovenweep National Monument. embodied energy product. What one saves...

Suspended Brick Weights

We started out like everybody else using the most primitive available strategies for building earthbag walls. We used flat rocks or bricks to hold the springy barbed wire down while laying the next row of bags. This works fine for building a low garden wall. As the wall gets higher, though, it becomes a pain in the butt to have to keep heaving the bricks on and off the wall. So, in keeping with FQSS, we devised a technique that solved the brick-heaving dilemma and turned out to serve another...

Passive Solar Gain

Traditional earthen architecture limits the invasion of direct sun through large glass openings for a couple of reasons. First, earthen buildings rely on sufficient mass to provide stability. Big windows mean less wall mass. Second, glass is a relatively recent invention compared to the thousands of years dirt architecture has been around. Earthen walls act as a buffer from the assault of the sun in summer, and as an external heat sponge for absorbing the low-angled sun in winter (Fig. 17.5)....

Introduction to Alternative Roof Systems Without Bond Beams

Traditional earthen architecture was built without concrete, steel, or fossil fuel products. We feel that, in most cases, concrete and heavy wood bond beams are an unnecessary use of money and resources. (If you are considering building a roof system onto an earthbag structure without a continuous bond beam, please review Chapter 5). As a review, and to prepare for building a roof without a bond beam, these structural features should be taken into account. We would not advise putting a heavy...

Foreword

Gutsy because only the brave take up a construction method so different from the conventional. Gutsy because people build homes with this technique when they've just learned it. Gutsy because the materials are basic, elemental, primal. And gutsy, indeed, because this construction system resembles, in form and assembly, nothing other than our own intestines A shovel, bags, a little barbed wire and the earth beneath are all that are needed to build with...

Vaulted Viga Roof

One design we have been playing with is a vaulted viga roof that uses parapets on the two sides and eaves on the ends. It is our version of a low-tech organic substitute for a singlewide mobile home. Its long, narrow shape provides short spans, while interior intersecting walls and external buttressing add stability and charm (Fig. 9.16 & 9.29 on page 121). 9.17 (above) Vigas set parallel to each other with latillas set in an alternating diagonal pattern. 9.18 (below) A great example of the...

Advantages of Earthbag Domes

Structurally, the distinctive difference between earthbag domes and brick domes is their higher tensile strength, derived from the installation of two strands of barbed wire per row. In essence, the added tensile strength combined with the woven polypropylene fabric helps unify the individual rows into a series of stacked rings. Each of these complete rings creates a mild tensionring effect, offering tension under compression throughout the whole dome not just at a single bond beam. Excellent...

Insulated Light Wood Frame

People living in high rainfall areas, heavy snow country, or areas with abundant access to wood products, can secure light, wood frame rafters to built-in extended eaves. We recommend light wood frame as an alternative to larger dimensional lumber. Not because the dome cant take the weight, but to reduce timber consumption (Fig. 13.9). Exterior wood-frame roof systems can be insulated, sheathed with wood, and covered with any kind of roofing material, like metal, wood, asphalt shingles, or...

Leaning Vaults

How Put Roofing Sandbag House

The other style of vault construction is called a leaning vault. It was developed by Nubian builders as a way to build vaults with less material and zero formwork. A leaning vault transfers most of its compressive forces to whatever it is leaning on at either end rather than out to the sides, like a keystone vault. The wall that the vault leans on is its buttressing, and must be of substantial thickness to counteract the weight of the leaning vault. A leaning vault can be built up against a...

The Code

John and Jane Doe worked hard for years to save enough money to buy a small piece of property where they always dreamed of living. Jane was chemically sensitive to many of the manufactured materials that go into the construction of new structures. For these reasons, purchasing a pre-manufactured home to put on their property was out of the question. Besides the toxicity of such structures, their cost was prohibitive, and to have a contractor build a wood frame house was beyond their financial...

Advantages of Earthbag Over Other Earth Building Methods

Cob Earth Building Method

We love earthen construction in all its forms. Nothing compares with the beauty of an adobe structure or the solidity of a rammed earth wall. The sheer joy of mixing and plopping cob into a sculptural masterpiece is unequalled. But for the first-and-only-time owner builder, there are some distinct advantages to earthbag construction. Let's look at the advantages the earthbag system gives the do-it-yourselfer compared to these other types of earth building. Adobe is one of...

Determining the Outward Forces of an Arch

Earthbag Arch

The steeper the sides of an arch are, the stronger it becomes. A steep-sided arch transfers the weight above it at a more vertical pitch than a shallow arch does. The shallower the pitch of an arch, the more pressure it forces to the sides, creating horizontal stress. Therefore, the shallower the arch, the more it needs to be buttressed to counteract this horizontal push. Here is a simple way to determine the amount of buttressing necessary for a given arch shape Fig. 10.9 . The distance...

Arch Window and Door Forms

Earthbag Arch

Although we use a flexible form for our walls we use a rigid form to make the empty spaces for our windows and doorways Fig. 2.22 . This is the only place that requires a temporary support system during construction domed roofs are self-supporting . The box forms 2.22 Rigid form supporting door and window placement. 2.22 Rigid form supporting door and window placement. are leveled right on top of the wall. The bag work continues on either side of the form until the top is reached. The arch...

The Dirt

Burying Earthbag

The dirt is the most fundamental element of earthbag construction. We strive for an optimal, rammed earth-soil ratio of approximately 30 percent clay to 70 percent sand. According to David Easton, in The Rammed Earth House see Resource Guide , most of the world's oldest surviving rammed earth walls were constructed of this soil mix ratio. We like to use as close a ratio mix to this as possible for our own projects. This assigns the use of the bags as a temporary form until the rammed earth...

Drawings for the Honey House

Drawing Earthbag Plan

Refer to Chapter 11 for detailed explanations on making architectural drawings for domes. The first drawing we made was an elevation sketch. This is essentially a cross-sectional drawing of the height and width and shape of the dome with foundation details and floor level indicated Fig. 12.2 . This shape closely resembles a catenary-shaped arch see Chapter 10 for more about arch shapes . The second drawing is called the floor plan. This is a horizontal cross-section showing the thickness of...

Stabilized Earth

Foam Render Domes

This dome is constructed of six-inch 15 cm thick rigid foam protected with a four-inch 10 cm thick layer of sculpted cement-stabilized earth by artist sculptor Robert Chappelle. What is truly remarkable about this home is that it is in central Vermont Fig. 13.5 . After much experimentation, Robert mixed the optimum ratio of cement a hefty 16 percent into his sandy reject soil, resulting in a plaster that has withstood the ravages of Vermont winters since 1994. His sculptures continue to endure,...

Bags and Tubes The Flexible Form

The bags we use are the same kind of bags used most typically to package feed and grain Fig. 2.12 . The type and sizes we use most often are woven polypropylene 50-pound and 100-pound misprints with a minimum ten-by-ten denier weave per square inch. The companies that manufacture these bags sometimes have mistakes in the printing process that render them unsuitable to their clients. Rather than throw the bags away, they sell them at a considerably reduced cost. The 50-lb. misprint bags come in...

Barbed Wire The Velcro Mortar

Stucco Wire

We use two strands of 4-point barbed wire as a Velcro mortar between every row of bags. This cinches the bags together and provides tensile strength that inhibits the walls from being pulled apart. Tensile strength is something that most earthen architecture lacks. This Velcro mortar, aided by the tensile quality from the woven polypropylene bags and tubes, in particular , provides a ratio of tensile strength unique to earthbag construction. The Velcro mortar allows for the design of corbelled...

Straw bale Walls with Earthbag Foundations

Earthbag Foundations

Earthbags can be used to build foundations for straw-bale walls. Extra care should be taken to prevent moisture wicking up into the bales Fig. 17.12 amp 17.13 . iJf j j. through straw-bale 15 deep 100 lb. rawearthbag 50 lb. rawearthbags 100 lb. rawearthbag 50 lb. rawearthbags metal weep- screed or 1 diameter hose secured to tie wires 17.12 Grade level earthbag foundation for non-load bearing straw bale walls. 17.13 Insulated below grade level earthbag foundation for straw bale walls. two rods...

Foundations

Earthbag Foundations

This has been the most exasperating chapter for us to write. Both of us had done a lot of conventional construction prior to getting involved with earthbag building. Maybe it's just us, but we both dread the idea of building a typical concrete foundation system. To us they are boring and tedious to construct. They are expensive and use up godly amounts of natural resources while pumping the atmosphere full of ungodly amounts of pollutants. Plus, they don't last very long. A typical residential...

Designing Drafting an Earthbag Dome How to Use an Architectural Compass

Drafting Tools Images

An architectural compass is the dome builder's friend, so let's get acquainted with the new toys we will need to design an earthbag dome on paper. We will need An architectural-student-quality drawing compass preferably with an expandable arm A three-sided architect's or engineer's scale ruler in inch or centimeter increments A good mechanical pencil and eraser A two-foot 0.6 m long T-square A combo circle template optional A flat surface with a square edge like a pane of glass or Plexiglas or...

Foundation and Stem Wall

Interior Earthbag

We began our bag work right on the ground of this excavation these bags became the foundation of our structure. The first row of bags can be filled with gravel to inhibit capillary action from the ground up into the earthen walls. The continuing bag work up to grade consisted of the earthen fill we had prepared previously Fig. 12.6 . Use the compass arm to delineate the shape of the structure. The angle bracket set on the horizontal arm denotes where the inside circumference of the finished,...

The Reciprocal Roof

The reciprocal roof is a self-supporting spiral. An ingenious example of geometric harmony, it was reintroduced by a gentleman named Graham Brown. When pressure is applied from above, the spiral twists upon itself rather than spreading apart, the opposite dynamic to a compression roof Fig. 9.24 . 9.22 Light-wood, compression-style roof with extended eaves on earthbag walls. To us, the reciprocal roof is an ideal, exciting, and beautiful way to cap a round house without a bond beam. Fig. 9.25 ....

Lintels

Lintels are to earthen architecture what headers are to stud frame walls. A lintel is a sturdy beam that spans the space above a door or window opening that bears the weight of a roof or second story. Traditionally, they were made from large dimension lumber. These days, lintels are often built up from laminated small-dimensional lumber or constructed into a box beam. Pallets are an excellent resource for Velcro plates and for making laminated lintels. Whatever the design, our focus is on how...

Construction Size Architectural Compasses For Domes and Round Vertical Walls

The Pole Compass with Articulating Arm Fig. 3.40 The easiest way to maintain a precise circle during construction is by using a compass as a guide. For our purposes, a rigid pole compass works best and we use it exclusively for a variety of building designs. The pole compass can be used for both dome building and the construction of round vertical walls like kivas, hogans, and yurts Fig. 3.41 . The pole compass uses a tall center pole with an arm attached to it that is the length of the desired...

Living Roof Fig 928

Earthbag Vaulted Home

The use of living roofs has a long history that extends throughout almost every continent. North American Indians built a variety of buried pit houses protected by sod. Europe has a tradition of living roofs that come abloom with wild flowers in the spring. The benefits of a living roof are succinctly described by Christopher Williams in his book, Craftsmen of Necessity. As the seasons pass, the sod perpetuates itself root intertwines root, and the roof becomes a solid whole which rain and...

Site Evaluation

French Drain Detail

Evaluating the building site for an earthbag structure follows all the same criteria as any other structure. If you are on a flat plain with decent drainage or a southern slope, you have an ideal opportunity to partially bury or berm your structure. Fairly stable soils and sandy soils are ideal for buried structures. 4.18 Penny Pennel's 36'- Diameter Bermed Earthbag Kiva Southern, AZ. line bottom of trench with sand to support pipe and pro -tect fabric from 4 diameter perforated pipe with holes...