Strategies for Keeping Cool Wall Mass

In the desert, where cooling is a priority, thick earthen walls do an excellent job of maintaining a pleasant 17.2 Lime whitewashed walls reflect the sun s intensity in sunny climates. interior temperature. The key word here is thick. Exterior temperatures penetrate an earthen wall to a depth of 12 inches (30 cm) before the momentum of the external temperature is dissipated. When simply relying on mass alone to moderate internal temperatures, consider using the wider 18-20-inch (45-50 cm)...

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

Buttress Wall Earthbag

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...

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...

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...

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,...

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...