Earthbag Construction Techniques

Affordable Construction Alternative

We live in a world of concrete, glass, and steel.

Affordable housing is the everlasting dream of anyone who wishes to settle down and have a place to call home.

People are finding creative ways to improvise their temporary homes. Still, when it comes to construction of the permanent residence, earthbag construction is one of the most affordable, inexpensive building method to build structures which are strong and durable.

With this technique, buildings can be constructed quickly using mostly local soil, which saves time and money.

Natural Building Techniques

A trend of natural building techniques includes construction systems and materials that are sustainable and renewable.

People are looking for durability and the use of materials that produce a healthy living environment and manage to keep high indoor air quality without sacrificing comfort or good health.

To be sustainable, earthbag construction uses primarily abundantly available materials.

It is a natural building system that originates from military bunker construction methods.

It also has some similarities with temporary flood-control dike construction techniques.

It requires fundamental construction elements like strong sacks stuffed with organic material, which is usually available on construction sites.

Walls are steadily built up by placing the bags in sequences — forming a bricklaying pattern.

The walls can be assembled to be rounded or straight, covered with earth, or with traditional rooftops.

Curved walls are trendy for their ability to provide excellent stability and form igloo type round rooms.

Earthbag Construction

Earthbag construction housing requires little more than bags, barbed wire, and a few other tools. The earth is available in the surrounding region, which significantly reduces the energy demands and construction costs.

This type of construction is nothing new since humans have used the ground beneath them to build homes for thousands of years.

But when you apply modern-day materials to this ancient building technique, you create a durable and robust construction technique.

The one that is needed today to address affordable housing needs in the developing countries and disaster-hit regions.

Earthbag construction begins with the digging of a trench which penetrates down to the mineral subsoil.

The subsoil is then filled with gravel to create a foundation. Several layers of gravel form a water-resistant foundation.

Each layer is usually topped with strands of barbed wire that connect the bags to prevents slippage.

Barbed wire also helps to resist an outward expansion of the walls. Each successive layer of bags is offset by a half bag’s width to form a staggered pattern.

The most popular bags to use are polypropylene bags due to their water and insect resistance, although hemp and some other natural fibers can be used to produce proper bags, given they are filled with a high-percentage clay material.

The reason is that clay will help the bags to mold around the barbed wire, improving the strength of the walls.

The insulating properties of the fill material should be considered, particularly in climates with extreme temperatures.

Clay and sand have excellent heat retention characteristics and are popular choices in cool climate destinations, keeping the internal temperature stable throughout the year.

After the construction of the wall, a roof can be formed by sloping the walls inward to create a dome, or a traditional roof can be added on top of the walls.

Windows and doors can be created using brick-arch techniques. An exposed outer surface of lime or earthen plasters also needs to be added to prevent damage from moisture or UV rays.

As earthbag construction evolved and found its use, especially in disaster-stricken areas, the accurate terminology is developed to distinguish different types of earthbag construction.

Contained earth(CE) is referring to the original technique with specific soil strengths and reinforcement chosen for hazard levels.

It uses damp and cohesive bag fill, which bonds strongly with barbed wire and other support as the wall construction progresses, so CE does not stand for sandbags.

Contained sand (CS)structurally performs like sandbags and uses sand fill or any fill with poor cohesion.

CS must be built with solid-weave fabric bags, as the wall strength depends on the power of the bag fabric. CS also needs more vertical reinforcement than CE. Contained gravel (CG) uses fill of any material larger than coarse sand, usually in doubled rice bags.

The main advantages of earthbag construction are the minimal energy requirements, with earth already available as material. Because earthbag structures are made from natural materials, they can erode with no threat to the environment.

Earthbag construction is beneficial in regions with limited trees as it eliminates the need for wood resources.

Some propose earthbag construction be used for building structures on Moon once we begin to colonize it so that we will witness the evolution of this technique in the future.

Image courtesy to: Flickr Kelly Hart