Earthbag or sandbags building have been developed gradually from 100 years of military building structures out of sandbags. It is a structure that is nontoxic, sustainable, fire and rodent proof, quiet and has a great resistance towards flood and hurricane. This type of home also provides protection against bullets and blasts of any kind. Here are the basic steps on how to build an earthbag home.
Things that you will need:
- Earthbag (sandbags)
- Bucket, shovel
- Water or garden hose
- Soil/other fill material
- Barbed wire
- Level and wire cutters
- Dig a trench a little wider than the earthbag walls about 18″ to 24″ deep to build a rubble trench foundation. Leave a 6″ to 12″ of space on top for 1 or 2 courses of earthbag and add gravel to the trench. To prevent moisture-damage to the earth-filled bags, add several courses of ¾ full of gravel-filled bags. Proceed onwards by tamping and leveling the bags after each course is completed.
- To give strength, add a 4-point barbed wire between each course. Vertical walls on a small house need only one strand while the two strands are for vaults and domes. You can extend the wire for about 18″ extra and connect it with a tie wire or a baling wire. Place the bags on top of barbed wire with the help of a metal slider. Once the bag is correctly aligned, hold it in place and pull the slider out quickly.
- Add the door form on top of the earthbag wall. The location is usually 6″ above grade. You can build it out from scrap wood, install it plumb and level.
- Start adding the remaining courses. You can use a plastic bucket with the bottom cut out as a funnel to help fill the bags. Tamp the bags solid after each of the course is complete. You have to make sure that the walls remain plumb, leveled and straight. Make sure the course is round if you are building a dome structure.
- Next, install the window forms at the suitable level. You can use scrap woods, barrels, tires, wagon wheels or steel culvert pipe.
- Add the remaining earthbags and always check out if the structure is plumb, straight and leveled. If you prefer not to use lintels, make sure the bags is leveled with the top of your doors and windows. Structures with vertical walls except domes should be added with a bond beam from reinforced concrete or wood. Continue the stacking until the full structure complete.
- Build the roof and install the doors and windows. To protect the walls, build a wide roof overhangs about 36″ or 1 meter.
- Plaster the walls with lime or earth plaster depending on the climate and situation you live in. Earth plaster is used for walls protected by roof overhangs. Lime plaster will give more protection for domes structure.