Smart-Ass Answers(to Reasonable Questions)

Where can I find bags?
See our links page for a list of bag suppliers. You can also do an Internet search for "agricultural bags" or "agricultural bag suppliers".
What happens when you get a hole in the bag?
“Oh, no! Look, a hole! Now we have to build the whole wall over again!;” True or False? False! Ha! The correct answer to the original question is: nothing! Since the earth is dampened prior to being placed into the bag, once a whole row is laid it is compacted from above with hand tampers. The earthbag compacts to two-thirds or one-half of its original volume resulting in an extremely hard block of earth. Once cured, the bag becomes superfluous. A hole or tear in the bag will not cause the earth to come pouring out like the sand spilling inside of an hourglass! We have had bags left exposed to UV sunlight completely disintegrate while the rammed earth inside remained perfectly intact. As long as there is some moisture in the soil when it is compacted it will form a stable block. Even pure sand will compact to some degree, certainly enough to prevent spillage out of a hole. If it really bothers you, a small hole can always be patched with duct tape.
What happens to an earthbag house when it rains?
It melts! Ha-ha - just kidding! Just like any other type of house, an earthbag house needs to be designed to suit the climate. The wetter the climate, the more protection the roof should provide to shed rain away from the walls. Extra long eaves and a tall, stabilized stem wall are simple design features that provide ample wall protection. Additional considerations are wrap-around porches and an erosion resistant lime or cement base plaster. Remember, sandbags are used for flood control and designed to be able to endure submergence in water. They resist mold, rot, warping, twisting and termites unlike more common building materials like wood.
What kind of R-Value does an earthbag wall have?
I can't think of a smart-ass answer to this question, but, typically, earthen mass has a very low R-value of approximately 0.25 per inch. But it has a high U-Value. U-value stands for Units per Thermal Radiation. Earth has a high mass value that acts as a thermal storage bank able to absorb warmth generated from inside a building from (for example) passive solar, or forced air, or a wood stove that is then absorbed by the walls. This warmth is slowly released back into the living space helping to regulate the internal temperature in an active style. R-value on the other hand stands for Resistance. R-value is a measurement of how much resistance to change is provided, like that imparted by insulation. Think of a sleeping bag on a cold night. The more sleeping bags you have around you, the longer it will take for the outside temperatures to affect the temperature inside the bag. Mass works best in a climate that has a lot of sun to warm the exterior walls as well as providing an internal heat sink for passive solar application. In a really cold, cloudy location, an earthbag wall would be more effective with insulation added to the exterior walls. This can be done with rigid foam or straw bales attached to the walls. Another way to take advantage of the regulating effect of the earth itself is by berming an earthbag structure into the side of a southern slope or at least sinking the floor level below frost line. As the earth below frost line maintains a stable temperature of 52°F to 58°F, it will never freeze and will use far less energy to heat in the winter or cool it in the summer.
How big can you build and earthbag dome?
As big as you have the time, money, friends/labor force, scaffolding, perseverance, patience, and determination to achieve it! In Thailand, Trevor Lytle built the largest earthbag dome we know of with a 24-feet interior diameter. It was built as a sound temple in a workshop environment during a 5-week period with a crew of 10+ people. Keep in mind we design corbelled earthbag domes to be as tall as they are wide for strength and stability. Rather than building one big dome, consider building smaller multiple interconnecting domes. Interconnected domes have an aesthetically pleasing roof profile than one big lump, and they are stronger and more manageable in height to construct.