Sliders

After laying our Velcro mortar (4-point barbed wire), a slider is placed on the wall and the bag stand is set up on top of the slider. This allows the bag to be slid into the desired position on top of the barbed wire without getting stuck to it. Make sure to place the slider where you want the bag to be filled. The bag will still be heavy but relatively easy to maneuver on the slider until it is laid down onto the barbed wire. (Fig. 3.11). 3.10 Keep your eye on where you want the can to go,...

The Humble 10 Can

We use cans as hand shovels for scooping dirt out of wheelbarrows and passing it along to be dumped into a bag stood up on the wall. In terms of canned goods, they hold about three quarters of a gallon (2.8 liters). One can of dirt is approximately equivalent to one shovel of dirt. In our years of bag building, we have yet to discover a more effective way to move tons of dirt onto the walls than by hand with a can. A shovel tends to be awkward in that the handle swings around in someone's way,...

Pumice Scoria Earthbag Walls

If you live where either pumice or scoria is available, building the walls with up to 50 percent of either of these, with the balance of the mix compactable dirt, may add a degree of insulation. We've made both rammed-earth pumice bags and slurried adobe pumice bags at a 50 50 ratio of binder to pumice (see Insulated Earthbag Foundations Stem Walls in Chapter 4). These bags could just as easily be used to build whole walls, as they are still solid and strong, but weigh only 60 pounds (27.2 kg)...

The Proof is in the Pudding

Nader Khalili has demonstrated the structural integrity of his non-stabilized (natural raw earth) earthbag domes. Under static load testing conditions simulating seismic, wind, and snow loads, the tests exceeded 1991 Uniform Building Code requirements by 200 percent. These tests were done at Cal-Earth California Insitute of Earth Art and Architecture in Hesperia, CA., under the supervision of the ICBO (International Conference of Building Officials), monitored in conjunction with independent...

Cost Effectiveness

Materials for earthbag construction are in most cases inexpensive, abundant, and accessible. Grain bags and barbed wire are available throughout most of the world or can be imported for a fraction of the cost of cement, steel, and lumber. Dirt can be harvested on site or often hauled in for the cost of trucking. Developed countries have the advantage of mechanized gravel yards that produce vast quantities of reject fines from the by-product of road building materials. Gravel yards, bag...

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...

The Wedge Box Fig 319

The wedge box is a special form for pre-tamping the fan bags that surround the arch form. The wedge box is designed to pre-shape a proper wedge shape to accommodate any size Roman arch by simply adding or reducing the number of fan bags used. The wedge box holds a bag that is filled and tamped 12 inches (30 cm) high. If you fill a fan bag in the wedge box on top of the wall, the wedge box then can be opened to slide the pre-tamped fan bag into place around the arch form. You can use the wedge...

Tie Wires

Tie wires provide an optional attachment source for the installation of chicken wire (stucco mesh) or a sturdy extruded plastic mesh substitute (Fig. 2.20). At the time of laying the barbed wire, one needs to decide whether cement lime stucco, natural earth plaster, or earth plaster followed by lime plaster is going to be used as the finish coat. Clay-rich earth straw plasters adhere directly onto the surface of the bags as tenaciously as they would to the cover of this book. Cement stucco...

Designing for Your Climate

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...

Earthen Plaster

Earthen and lime plasters absorb and transpire moisture out through the walls, helping to regulate internal humidity. Properly mixed and applied, earthen plasters are mold, vermin, and UV resistant, long-lasting, durable, and above all, beautiful. Earthen plasters are a joy to work with and live within. They are naturally soothing to the senses and have mild detoxifying properties. We live in a dry climate where a clay-rich earthen plaster with lots of long and chopped straw holds up well on...

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...

Excavation

Let's begin the excavation by locating the center of the dome. Drive a stake or post into the ground at that point. Attach a non-stretchy rope or light chain to the center post so that it can rotate easily. Make sure it is long enough to reach beyond the proposed radius. Mark the rope or chain at least two feet (0.6 m) beyond the interior radius to include the width of the wall (Fig. 12.5). That is to say, if you are building a 12-foot diameter (3.6 m) interior dome, make a mark on the rope or...

Vaults

A vault is essentially a really deep arch, like a tunnel. There are two strategies for building vaults. Keystone vaults use the same form work we use for supporting arches until the keystones are installed. The forms must support the full length of the vault. Because of forces directed outwards from the keystones, this style of vault requires a tremendous amount of buttressing. This is the type of vault we built into the entrance of the Honey House. To create a vault, we extended our box and...

Dynamics of a Dome

Straight is the line of duty, and curved is the path of beauty. Hassan Fathy (1900-1989) This is, we feel, where earthbags exhibit their greatest potential to us, it is the essence of earthbag building. We are able to build an entire house from foundation to walls to roof using one system. (To gain greater understanding of the dynamics of a dome, please read The Dynamics of an Arch, in Chapter 10, to better acquaint you with some of the same language and principles that are inherent in both. We...

Insulation Strategies for Earthbag Walls

Exterior insulation helps to make more efficient use of earthbag mass by creating an air buffer of resistance to extreme external temperature changes. Here we offer a few techniques for attaching various insulative materials to earthbag walls, from minimal R-values for moderately cold climates to mega-insulation for long, bitterly cold winters. 17.6a & b Bermed oval-shaped vaulted viga earthbag cottage with enclosed wraparound sunroom and living straw bale roof. 17.6a & b Bermed...

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...

Installing Door and Window Forms

After completing one full circle of way-too-big stem wall bags, we installed the door form, a three- by three-foot (90 by 90 cm) rigid box form. We used the compass to designate exactly where we wanted to position the door. We set the lower portion of the box form on the wall, raised the horizontal arm on the compass to the same height as the box form, and squared it down the center of the box (Fig. 12.12). With a marking pen, we drew a line on either side of the box right on top of the tamped...

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...

Cautionary Note On Safety

While excavating and throughout the building process, maintain a tidy work site. This not only makes the work go more smoothly, it provides a degree of safety for yourself and anybody helping. Construction sites are notorious for incidents of minor and serious injury. Each day's work should include careful examination of the jobsite for potential hazards. Take the necessary precautions to ensure a safe, happy worksite. Nothing puts a bigger damper on a fun, cooperative project like a trip to...

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...

Installing a Vinyl Window into an Earthbag Arch Opening

Earthbag Arch

The appeal of vinyl is its low cost, compatibility with mud, efficient seal, thermopane glass, and fitted screen Secure the window in the rough opening with shims, making sure to check for level and plumb. Trim the exterior flange on the pre-manufactured window if it is too wide hand pruning shears work great for this . Install a sloped two-by-four sill on top of the window. Add a stop along the top of this sill to rest the half-round glass flush against Fig. 8.6 amp 8.7 . Mud it into place,...

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...

Earthbag Domes

The construction of Nubian style adobe brick domes is ingenious, but extremely difficult to replicate with earthbags. We are limited to the corbelling technique, based on the nature of working with the bags themselves. By corbelling the rows of bags or tubes, we maintain a flat surface to stand on while filling and tamping the bags in place meeting FQSS principles. As the bags or tubes are stepped in every row a little at a time gradually decreasing the diameter , the walls eventually meet...

Type SHydrated Lime

Type S lime is mined from magnesium-rich dolomite limestone that has been fired to produce quicklime, ground into a powder, and then hydrated under pressure in a controlled manufacturing process with just enough water to thoroughly react with the quicklime without saturating it. It is sold bagged in a powder form. Type S lime should be purchased in as fresh a state as possible. The problem with using Type S-Hydrated Lime if the bag is not fresh is that the carbonation process may have already...

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...

Height to Width Ratio

In addition to lateral support, buttresses as well as curves follow criteria for determining their height to width ratio. For every foot 30 cm of wall height, add six inches 15 cm of width to the wall, either as total thickness, or as a curve or buttress. In other words, the 5.6 Examples of height to width ratios for curved, freestanding walls. height to width ratio is two to one expressed as 2 1, height to width Fig. 5.5 . Curved walls follow the same criteria by squig-gling in a curved...

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

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...

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...

Second Story Floor Joists

If you are planning to install a loft or second floor, wait until there are at least one or two rows of tubes over the tops of the finished arch windows. Two rows are better, as the seams can be staggered to help create as much of a tension ring as possible, although the door may still be under construction. A second story makes a great interior scaffold as well, even if built solely for the construction process and sawn off later. Except for a few more rows to finish the door, all bag work...