Not viewing this page correctly? Color will vary but the following are fairly good pictures of what the textures of these soils can be expected to look like: Gravel Soil Examples – Click to open the classification spreadsheet.

Straight walls are weaker than round ones. More sophisticated plans, drafted by Nepal’ growing class of experienced and talented Earthbag architects and engineers, can be custom-tailored to a particular client or site. And with all of that computing power in the hands of so many people, software engineers are at the leading edge of the work to improve lives. It is calculated in cell B24 and using this formula: S (Snow load) = SL x AT. Close top tightly.

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Determine the highest vertical and horizontal load per linear foot under section in cell A31 : “Maximum Load Combinations for LRFD as per ASCE 7-16 Chapter 2” in the spreadsheets “Gravity and Wind Loading” and “Gravity and Snow Loading.” The highest among both will govern, and hence be used for analysis.

Tilt bag down against previous bag. (2015, September). You can also use strawbales, barrels or drums, wagon wheels, and tyres. Place the window frame so the lintel level coincide with the bondbeam level. The usual check for clayey soils involves checking if the soil with enough water content can be rolled into 2mm thick threads without any significant break lines observable. Some builders tuck the corners in (diddle them) or pin them to make them neat so walls are flat and smooth. Engineering calculations on the soil, bag strength, and nails showed that using a 12” course thickness (aka bag height) with 1000 psi Soil-Cement mix and finishing-nail strategy should produce a safe structure when constructed on flatland. The following symbols are used within these spreadsheets, taken from cells A5 to A18 in both sheets. See row 51 and below for the nail/rebar spacing and configurations we tested as successfully passing the “Bending Strength of Nail” (cell B42) criteria also. Pricing of 12D Nails per Home Depot Website: $18.59/5 lbs (315 Nails), Pricing of 10D Nails per Home Depot Website: $18.59/5 lbs (340 Nails), Pricing of 12D Nails per foot = $ 0.35 / foot, Pricing of 10D Nails per foot = $ 0.76 / foot, To change the nail/rebar choice, modify cell B7 (notations are used in USA terms), Next, input the spacing (in inches) you intend to us in cell C10, And then input in cell C11 the number of rows you’d like to use with this spacing. The width of the trench should be the same throughout the trench and the entire bed should be leveled. Plasticity is the property of a material to be deformed repeatedly without rupture by the action of a force, and to remain deformed after the removal of force. For all of its importance, the issue still gets little attention. If your windows or door frames are not arched, you need nice fat lintels instead.


is the best way to ensure your windows stay in shape. To construct earthbag structures, soil is mixed with a small amount of stabilizer, usually cement or lime, and then used to fill degradable bags.

Earthen or lime plaster can have a less expensive earthen base coat to level a bumpy wall. Tamped earth floors dry more quickly and can be finished permanently with an attractive oil sealer.

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See the nails section below for more on this. A Material and Structural Analysis of Earthbag Housing. There is, however, a right way and a wrong way to build with Earthbags in Nepal. Place the bag where the bottom will be near the end of the slider so pulling it out is easier. Stand several feet away in line with the wall and eye the wall for bulging bag corners or any bags that aren’t lined up properly.

Evenly tamp the entire wall several times as you continually move the tamper.

if it's lying about.

Vertical walls can also benefit from tubes to speed work and reduce plastering needed to fill nooks between courses and bag ends. Add rubble until level about 6” below finished grade. That, in essence, is the higher service to which we are all being called.". To determine the cement content necessary for preparing soil mix using soil at the site, it is of utmost importance to determine the type of soil at the site. Yomi Sanyaolu: Mechanical Engineering Graduate and Technical Writer (editor, secondary researcher). After the threshold is done and fully cured you can install the door frames in place where doors will go. Double-bag the gravel for added strength. Starting on the second course, the slider will keep bags from getting hooked on the barbed wire. access to exclusive engagement opportunities and the E4C My earthbag house took six weeks to build and cost about US$5000 to make. The first bag holds the second shut.

If you plan to build in a hilly area, excavate a flat area so that it will have a level floor inside. Q: Where do I learn more about One Community’s earthbag structures? relevant to you. This section is designed to help you understand the various failure modes described on the Nail Design spreadsheet. Necessary cookies are absolutely essential for the website to function properly. This should be inclined, not vertical, and should extend 6 inches outside the wall which will anchor into the bond beam.

The bags themselves have a tensile strength even higher than steel, and can resist circumferential forces generated from the weight above.

Rubble Trench Foundation.

Earthbag technology has emerged as the building method best suited to rebuild rural Nepal after its devastating 2015 earthquake. Earthbag construction is durable, and if the polypropylene bags are plastered properly the construction can last for hundreds of years. First of all, take an earthbag and fold the corners in.

If the soil contains too much sand the soil will not bind together and the structure will be weakened. Diarrhea is one of the leading killers of children under the age of five. Further classification of sandy soil depends on its contents. Croft, C., & Heath, A.

After each added bucket of soil, use a small tamper inside or outside the bag or press the bag with your knee.

Moderate tamping may be fine, but well-tamped walls have extra strength. Work from the corners of walls or openings towards the center. To do this, perform a compression test using a universal testing machine (UTM) and a soil mix cube (of your specific mix) to determine the compressive strength of the combined earthbag and soil mix. If the soil has >12% fines, it is classified either as Silty Gravel (GM) or Clayey Gravel (GC).

Earthbag technology also requires less expertise than more traditional building methods, and only the simplest of tools. Our hope in sharing what we’ve learned is to increase public safety and improve the performance of earthbag-constructed structures.


Clayey soil particles pass through a 5mm sieve and are classified into Low Plasticity Clay (CL) or High Plasticity Clay (CH) based on their plasticity limits.

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At least two strands of 4-point barbed wire should be used in-between each course of bags.

As noted above, a study by the U.S. Federal Highway Administration found that the half-life of polypropylene fabrics in benign environments could be 500 years or more. Retrieved March 12, 2016, from:, Irene Turner (2016).

Topsoil lies on the surface of the ground, is usually of a darker color, and contains rotting leaves or roots. Identifying what type of soil you have – Click for the open source spreadsheet. Hammer first rebar at seal level and second rebar at lentil level.

This classification cannot be done at the site due to experimental equipment required.

Make sure the rebars are long enough to have at least 1 foot overlap within the wall. Mud plaster takes long time to prepare so it’s better to start preparing it before the construction starts.

For the nail strategy, 12D finishing nails placed 6 nails per foot (as 1 row) and with a 2” embedment into the bottom course was the best choice.

Avoid putting earthbag on top of the openings. One small to medium size project (300 – 1200 sqft) can be built with only one supervisor, however if the project is bigger we recommend to add more supervisors.

Shear failure is caused by sliding between two subsequent earthbag layers; this friction induces shear loads. For maximum safety, we also think (as we’ve said above) that the tests listed in the “Additional Recommended Engineering Tests” section should be performed.

Many builders choose an attractive plaster color and extend it right up to windows, doors and floors. The main task to complete when using this spreadsheet is to answer the soil classification checklist questions in cells I4, I6, I8, I10, I12 & I14. Add water if needed to achieve 10% moisture. You also have the option to opt-out of these cookies.

This mandatory step will result in stronger walls. Earthbag Options for Nepal: Draft Guidelines for Reinforcement.

Earthbag construction in Nepal generally employs a rubble trench foundation and a lightweight roof. In a rectangular building, the location that starts the bond pattern is the corner where every other course has a bag end. If you will use an earthen or lime plaster inside and a more expensive cement stucco outside, keep the outer wall smoother than the inner wall. Also assess the displacement of the nail so as to satisfy displacement criteria recommended by building codes. Compressive failure is due to crushing of the soil mix via load transfer between two subsequent Earthbag layers. If it cannot, it is either MH or ML silty soil. ​"If you've ever thought about going off-grid...this book is a must read.". Clayey Soil Example – Click for the classification spreadsheet.

If you make a copy of the spreadsheet, you have the complete freedom to edit it. Women are under-represented in engineering, yet… Polypropylene bags or tubes are susceptible to ultraviolet (UV) damage if left exposed to sunlight for more than 1 month, and UV damage cannot be reversed. Keep laying bags until you finish a circle.

Make a custom bag to fill the small spaces. Mine has survived four major earthquakes and is in exactly the same condition it was when I built it.

Plasticity is the property of a material to be deformed repeatedly without rupture by the action of a force, and to remain deformed after the removal of force. Place bag on the slider so the joint will be offset from the course below.

Having evolved from military bunker construction and flood control methods, Earthbag buildings are notable for their ability to endure fire, flood, wind, earthquake and vermin, and have been used in disaster-prone zones all over the world. (n.d.).

Here we discuss our earthbag engineering findings and the process we used to get the results we did. Retrieved January 10, 2016, from:, Bidoun (2004).

The tests in the “Additional Recommended Engineering Tests” section below are also recommended. Once a member, the more content you engage with, the more relevant we can make it for you!

The distance between rebars should be maximum 3 feet. Members are in the know! Use of this website constitutes acceptance and agreement to comply with and be bound by these Terms and Conditions. See rows 24 and below for the process of calculating this value.

This would be a test to determine the nail behavior between the earthbags. Use a plumb-line to check.

Use gravel-filled bags until 6” above the risk of moisture damage. Tamp the sides of the bags to flatten walls.

Here is the data to support the above findings. AT THAT TIME WE WILL ADD HERE THOSE PERMITTED PLANS AND ANYTHING ELSE WE LEARNED. When you lay earthbags over these slats to fill in the gaps, the roof becomes mighty secure.