| By now you've probably heard of earthbag | | | | up into upper courses. In cold climates you can |
| building and are looking for more detailed | | | | use lava rock or pumice to create an insulated |
| information. This article summarizes how you can | | | | foundation. Fill the bags about ¾ full and |
| build safe, beautiful and durable homes, offices | | | | fold the end underneath. If money is really tight, |
| and shops out of earthbags (sandbags) for very | | | | you can stitch the ends closed and save on bags. |
| little money. | | | | A 'bucket chute' (plastic bucket with the bottom |
| For those of you new to earthbag building, here's | | | | cut out) helps holds the bag open and makes it |
| a quick overview. Earthbag building has evolved | | | | easier to fill. Tamp the bags flat after each row is |
| from the military's use of building with sandbags | | | | complete. Add one or two strands of 4-point |
| to build blast and bullet proof structures. Sandbags | | | | barbed wire between each course. Two strands |
| also have a long history of use for flood control, | | | | are recommended for domes. Bricks or rocks are |
| which demonstrates their incredible strength, | | | | helpful for keeping the wire in place. Use the slider |
| moisture resistance and ease of use by novices. | | | | starting on the second course. The slider allows |
| A big reason for the growing popularity of | | | | you to position the bag above the barbed wire. |
| earthbag building is its low cost. You can build small | | | | When the bag is aligned, hold it in place and pull |
| domes for $100-$1,000. For $1,000-$5,000 you | | | | the slider out with a quick motion. Add courses |
| could have a nice, small home that would likely | | | | until you're at least 6" above the risk of moisture |
| outlast most conventional wood-framed houses, | | | | getting in the walls. Domes require two stakes |
| and be quieter and more comfortable. | | | | and stringlines. The center stake is used to verify |
| The building process itself is as simple as filling | | | | roundness. The second stake defines the dome |
| bags with soil, gravel or insulation, stacking in level | | | | curvature. For domes, each course of bags is |
| courses and tamping them solid. Barbed wire is | | | | corbelled - they overhang the previous course |
| placed between courses for added strength and | | | | slightly. It is best to keep earthbag walls |
| to prevent slippage. Earthbags excel at providing | | | | protected from sunlight with tarps until plastered. |
| dirt-cheap housing in harsh climates and areas | | | | 4. Set the door form(s) in place. Plumb and level |
| prone to disasters such as hurricanes and floods. | | | | the form(s), and brace in position. Forms for |
| It's easy to create curved walls, domes, | | | | doors and windows can be built with scrap wood |
| roundhouses and other shapes for above grade | | | | from pallets, or you can use barrels, tires, culvert |
| or below grade structures such as rootcellars and | | | | pipe, wagon wheels, etc. |
| storm shelters. The building techniques are very | | | | 5. Now you're ready to start building walls with |
| easy to learn and very few tools are required. | | | | soil-filled bags. You can also build walls with bags of |
| Things you will need: shovel, bucket, garden hose, | | | | scoria, pumice, perlite, vermiculite or rice hulls. This |
| wheelbarrow, gravel, soil, earthbags (sandbags), | | | | creates an insulated wall with bags that are light |
| barbed wire, wire cutters, level. Most earthbag | | | | and easy to work with. Most subsoils are |
| projects use 18" wide x 30" long bags when | | | | adequate and can be obtained from the site. Or |
| measured empty. Misprinted bags and recycled | | | | you can have road base, reject fines or fill dirt |
| bags from farmers and feed stores are often | | | | delivered by the truckload and save hundreds of |
| available at reduced prices. In addition, you'll need | | | | hours of hard labor. You can add sand or clay to |
| a tamper to compact the bags and a slider to | | | | modify the mixture. The best mix is about 25% |
| help place bags on top of barbed wire. Tampers | | | | clayey soil and 75% sandy soil. Stack the bags |
| are sold at large building supply centers, or you | | | | end to end with the folded end against the |
| can make one yourself using the free plans on | | | | previous bag to prevent spillage. Tamp solid once |
| our website. A slider looks similar to a cookie | | | | each course is complete. Check each course for |
| sheet, but with a larger grip on one end. It can be | | | | level. Adding the same quantity to each bag |
| made from scrap metal, such as old furnace | | | | (example: 4 buckets of soil) helps maintain level. |
| heating ducts. | | | | Repeat the above process for each course. |
| 1. The first step is to prepare the building site. You | | | | 6. Set window forms in position, and continue |
| want a level space clear of roots, rocks and other | | | | stacking and tamping bags. |
| obstacles, and with enough space to work and pile | | | | 7. For domes, you can continue the same process |
| materials. Remove and store topsoil for | | | | of corbelling each course. Near the top corbels |
| landscaping. Mark where the building will go with | | | | may get larger, depending on the desired shape. |
| temporary stakes and then stockpile mounds of | | | | For vertical walls, it's easiest to build a bond beam |
| gravel and earth (and insulation if you're building in | | | | immediately above windows and doors. This |
| extremely cold climates). Distribute the piles | | | | saves building lintels. Reinforced concrete or wood |
| evenly to minimize labor. Now you're ready to | | | | bond beams are both acceptable. |
| stake out the building with batter boards as | | | | 8. Build the roof if you're going with vertical walls. |
| conventionally done by carpenters. Check for | | | | Create large overhangs of approximately 36" to |
| plumb, square and level. For domes, put in a | | | | protect walls from moisture damage. |
| center stake and trace a circle in the earth using | | | | 9. At this point you can plaster the walls. In most |
| a length of twine. Locate where the plumbing will | | | | cases plaster mesh isn't required. For disaster |
| go and bury all plumbing lines before proceeding. | | | | prone areas, mesh is recommended. For high risk |
| 2. The easiest, least expensive foundation is a | | | | areas like earthquake zones, add mesh on both |
| rubble trench. Expensive reinforced concrete | | | | sides of walls and tie together. Plastic mesh may |
| foundations aren't needed. You can save | | | | be preferred because it won't rust. Fishnet is a |
| thousands of dollars on this step alone. Dig a | | | | low cost substitute, but not as strong. Also for |
| trench slightly wider than the earthbag wall. Dig | | | | high risk areas, you can add poly strapping that |
| the trench about 18"-24" deep and add gravel, | | | | runs under the bottom course and up and over |
| rocks or broken concrete to about 6" of grade. | | | | the bond beam (cinch together with a strapping |
| You want at least one course of bags below | | | | tool). Earth plaster is recommended for interior |
| grade. In wet climates, it's best to add a French | | | | walls and exterior walls protected by roofs. |
| drain to remove excess water. | | | | Domes require a more durable plaster, either |
| 3. Once the rubble trench is leveled, you're ready | | | | stabilized earth or lime. Additionally, you can create |
| to place the first course of bags. It's | | | | a green roof by covering the dome with two |
| recommended to double-bag the first few | | | | layers of 6 mil poly and then adding earth and |
| courses of gravel for added strength and peace | | | | plants. |
| of mind. Gravel prevents moisture from wicking | | | | |