In part two of 'Building with Rammed Earth', I speak to Donald Sequeira. Donald is an architect, natural builder, and the Director of Gia Mantra Global Village in Tiruvannamalai, Tamil Nadu, India. In this conversation, we take a deep dive into questions from students, practitioners and sustainability enthusiasts to clarify concerns regarding rammed earth as a building material. Through this Q&A session we touch upon various aspects including:

• The Building Process

• Strength of Material

• Potential of Construction

• Climate Feasibility, and

• Maintenance

Here are some interesting questions that we received over the course of the IG Live session:

1. Can a rammed earth structure be built in areas with heavy rain?

   A rammed earth structure can be built in any climatic zone including areas with heavy rainfall. The precaution to be taken is to ensure large overhangs are given to protect the wall from the rain. Additional surface treatments like waxing or plastering protect exterior walls for a longer period.

2. What is the ideal soil type for rammed earth?

   Yes. Rammed earth walls can be built out of most local soils but the clay content should not exceed 30%. If the clay content is higher, the soil can be mixed with other soil types or washed with water to dilute the clay concentration.

3. How are building services addressed?

   The electrical conduits and plumbing must be inserted while ramming. Prior planning is required. Otherwise, services can be added later but those surfaces may require plaster.

4. Are any surface treatments possible?

   Yes, rammed earth walls can be plastered, painted, and tiled over like any other wall. Clear treatments such as wall waxing are also possible.

5. Can river sand be added to the soil mix to reduce the clay content?

   Yes. However, river sand is not ideal because it is not a sustainable source. M-Sand is a good alternative to river sand and can be used as one of the mixture components.

6. Can a 4" rammed earth wall partition wall be created inside a RCC framed structure?

   A 4" rammed earth wall may not be possible since very little space is available for ramming. Furthermore, if the wall is planned beneath a pre-existing beam or a slab, it becomes harder to ram the top portions and close the gap. CSEB is a good alternative for built framed structures.

In this IG Live, I speak to Donald Sequeira. Donald is an architect, natural builder, and the Director of Gia Mantra Global Village in Tiruvannamalai, Tamil Nadu, India. In this first part of our conversation on 'Building with Rammed Earth', we understand the fundamentals. We understand the potential and constraints of rammed earth as a material and learn about preparing the material for construction. We speak about the material's strength and stability and understand construction concerns such as building height and services. We also discuss the durability and maintenance of rammed earth over its lifetime.

Here are some common myths about rammed earth debunked:

• A rammed earth structure can be built in all climatic regions.

  Rammed earth can be used for construction anywhere. It is a breathable but dense material that offers great heat exchange in tropical areas and thermal insulation in extremely hot or cold regions.

• A rammed earth building is durable and has a lifespan greater than concrete.

  Rammed earth structures also possess strength that is at least equal to the strength of concrete. They are extremely sustainable in the long run and require minimum maintenance.

• Rammed earth walls do not have to be very thick and there is no limit to room sizes.

  For a ground floor structure, only a 9" rammed earth wall is required which is equal to the thickness of a brick wall. As long as this criteria is met, it is possible to create spacious rooms of various sizes with rammed earth.

• There is no threat of insects or pests entering the house through the rammed earth walls.

  Once compressed, the rammed earth wall becomes extremely hard and dense. While the material is breathable, it is not not porous. The density does not allow for passages to be made by pests.

The feeling of being inside a rammed earth structure is indescribable. The structure changes with the weather to protect you. It has a quiet, special, womb-like quality - one instantly feels cocooned.

In this IG Live, we speak to Dr. Ajit Gokhale, the founder of Natural Solutions, India to discuss ‘Building Reed-bed system for Wastewater Management’.
Over our conversation, we get into details about the components of a Reed bed system, how the water purification is carried out, and the right methods of implementation. We also debunk common misconceptions about reed beds such as odor and maintenance requirements. Finally, we speak about the different types of flowering and fruiting plants that can be used for reed bed systems in Goa and along the Western Ghats.

Natural Solutions aims to spread environmental literacy and offers sustainable solutions for Urban as well as Rural Problems of water scarcity, Solid Waste Management, and wastewater treatment. Here are some key takeaways from our conversation.

Debunked myths about reed-bed systems

• A reed bed system does not smell if designed correctly. The simple precaution of introducing the inlet pipe at the bottom of the reed bed and not the top of the ensures that no foul smell is emanated.

• A reed bed does not have to be designed in a segregated area. It can very much designed as part of the landscape to be a walkable, usable space that can be accessed regularly.

• A reed bed can be used to effectively purify not just greywater but also black water and industrial wastewater when implemented correctly. It does not require significant additional maintenance.

Maintaining a reed-bed system

• A reed bed system typically consists of two parts - a sedimentation system (a septic tank/ an anaerobic digester/ Jalrakshak) and a filtration system (the reed bed itself). The entire system requires very little external care or maintenance.

• As with any common drainage or waste treatment system, the septic tank/ anaerobic digester/ Jalrakshak has to be cleaned occasionally.

• The reed bed itself does not require any maintenance. The plants can be trimmed for aesthetic value but it is not necessary. Trimming does not hamper the reed bed system as long as it is done as per a pruning schedule. Care has to be taken that the base of the plants are intact.

Benefits of a reed-bed system

• A reed bed system is a one-time investment with lifelong benefits. It is extremely low maintenance in the long run.

• Depending on the microclimate, the reed bed can purify every 1L of impure water to create 0.7 to 0.9L of filtered water that can be reused.

• The filtered water can be reused for irrigation & gardening, washing cars, and for flushing.

• The reed bed can be integrated as an accessible part of the landscape of the house with flowering and fruiting plants and trees that become home to local biodiversity.

Reed beds are sustainable, scalable, cost-effective ecologically engineered systems that can effectively purify wastewater. They are easy to maintain and can be designed into the landscape irrespective of the project size or typology.

Sustainable building is not as complicated as it sounds. Here are 5 simple practices to adopt while building which offer lifelong benefits and returns:

01. Harvest rainwater for reuse or to restore groundwater. Even a system as simple as a collecting tank makes a difference.

We have a conversation covering the basics of rainwater harvesting. Watch it here.

02 Source and use materials and natural stones that are local to the place.

Read about optimal use of local materials in this article.

03 Preserve existing trees and use native species. Use flowering & fruiting trees & plants to retain the habitat and welcome biodiversity.

Find out more about natural landscaping here.

04 Maximise daylight and cross ventilation by creating openings on at least two sides of a space.

Find out how to connect to the outdoors in this blogpost.

05 Create pathways and hardscape with permeable paving to allow rainwater to reach the ground and replenish the water table.

Learn more about designing outdoor paving here.