The magic of mud
It’s aesthetically pleasing, fairly easy to build with, does not need skilled labour and can be cost-effective sourced locally, says Anupama Mohanram
I have been fascinated by mud houses for as long as I can remember. That feeling of being enclosed within earthen walls, with its natural fragrance and visual appeal is truly invigorating. Mud houses stay naturally cool and breathable and have proven to be healthy for us as well as the environment.
Mud or earth is one of the most common building materials that has been used globally for centuries. Readily available all over the world, it is natural, pliable and attains strength over time. Being insulating and breathable, it is suitable for any climate. In addition, it is aesthetically pleasing, fairly easy to build with, does not need skilled labour and can be cost-effective if the mud is sourced locally. Dried naturally in the sun, mud construction does not involve the extensive firing or manufacturing process that other materials require, making it one of the most environmentally sustainable construction techniques.
Here’s how you can use the material in different ways:
Adobe: This method was originally widely used in North Africa, and in southern Spain. The word ‘adobe’ means ‘mud brick’ in Spanish. Soil is combined with water and organic binders such as hay and straw which also offer the tensile strength required. This soil mixture is then moulded into bricks which are dried in the sun and stacked to form walls.
Rammed earth: It is one of the earliest methods found to be first used in China and parts of Europe. Today we can find rammed earth structures worldwide. The technique involves compacting a damp mixture of soil and organic binders or stabilisers into a formwork. The soil mixture is compacted in batches until the height of the wall is achieved. A long ramming pole is used for tamping (compacting) the soil into the mould. This method results in beautiful, monolithic wall surfaces. The finishing of the wall surfaces can be done by carving or mould impressions before the wall dries.
Cob: This is yet another method found to be used first in North Africa and Spain. It has been widely used in southwest England since the 15th century. In Old English, ‘cob’ meant ‘lump or rounded mass’. This involves creating small hand sized lumps of the soil and binder mixture and stacking them in rows, stitching (tying) them together and allowing them to dry naturally until the walls go up.
The wall surfaces are literally ‘sculpted’ into shape, making cob construction a very aesthetic and sensory experience. Due to the simplicity and ease of construction, organic forms are a possibility using cob.
Natural mud hut with thatched roof known as ‘Bunga’ is found in Kutch, Gujarat | Photo Credit: Getty Images/iStockphoto
Compressed Earth Block (CEB): This is a method where walls are made from blocks of damp soil and stabiliser compressed at high pressure. A mechanical press is used for compression. If the blocks are stabilised with a chemical binder such as cement they are called Compressed Stabilised Earth Block (CSEB) or Stabilised Earth Block (SEB). These blocks are then assembled onto walls using standard masonry techniques.
These techniques aside, some of the other methods of using mud include the straw bale and wattle and daub. Mud construction and its benefits have been long forgotten in the quest for modernisation and mass-produced building materials. Today, however, it is heartening to see a renewed interest in the use of mud construction from people wishing to build independent homes.
Considering the state of our environment, this is a good time to focus on bringing back aspects of this wonderful construction methodology into the urban context.
The author is the founder of Green Evolution, a sustainable