Thesis on Earth Architecture

EARTH ARCHITECTURE

Innovations in earth construction and potential of earth architecture in

contemporary scenario

Approval

Undergraduate Research Thesis

Vyavasayi Vidya Pratisthan’s

Indubhai Parekh School of Architecture

Rajkot, India

The following study is hereby approved as creditable work on the approved subject,

carried out and presented in a manner sufficiently satisfactory to warrant its acceptance as

a prerequisite to the degree for which it has been submitted.

It is understood that by this approval, the undersigned does not necessarily endorse or

approve of any statement made, opinion expressed or conclusion drawn there in, and

approves the study only for the above purpose, and satisfies him as to the requirements

laid down by the thesis committee.

Thesis Title: EARTH ARCHITECTURE

Innovations in earth construction and potential of earth architecture in

contemporary scenario

Name: Bhavi Vador Guide: Vishwanath Kashikar

Roll No: 3805 Signature:

The dissertation is dedicated to my parents and to every individual who inspired me, guided me and

helped me in my endeavours.

Acknowledgement

Inspirations and critique makes individual to do better. Ultimately, an individual grows through such individuals. I would to acknowledge a number of individuals who have played a pivotal role in the actualisation of this thesis.

Firstly, i would like to thank my parents and whole family for supporting me throughout my life till now, they have given me this wonderful life by supporting me and making me an individual to stand out and face every difficulty that comes along the way of progress.

I am very much thankful to my guide - Vishwanath Kashikar for guiding me, providing me sufficient and timely discussions and valuable inputs and broadening my concepts and ideas about earth architecture.

All my people who helped me in one way or the other, who questioned, criticised and discussed factors related to the topic and thereby create a formwork for the dissertation. I would like to acknowledge not only those who directly contributed to this dissertation, but also those whose moral support and confidence in me, whose companionship and discussions I have always valued.

Ar. Nirav Vador and Ar. Kartik Bijlani for being a guide throughout, Dr.Tejal Gajra, Dhaval Vador and Jill Vador for asking me thousand times ‘when will you complete your thesis?’ .Nikitasha Vador for accompanying to auroville and making the trip memorable and helping with the work there.

Jimmy katira,Sweta Amin, Krishma Shah, Rutvik Agnihotri,Chandni Parekh,Tejas Bhatt,Pranav Meghani,Mitul Shah, Dhruvansh Hirani,Ronak patel,Ankit Mehta and Siddharth Chauhan for discussing the work, for being there in happy and low times and for being the best persons in my life.

Anand Dave, Kanupriya Raniwala, Saumil Mewada, Bhaumik Modi, Pratik zaveri, Sridevi, Rosy for valuable inputs and discussions.

Prabhulal Vora, Savita Vora, Pallavi aunty, Shailesh uncle, Parth Amin and the ‘shailvi’ home...for supporting and giving every facility to get a working environment.

IPSA for being a wonderful platform for providing knowledge and all the faculties, students, administration people, maintenance people for sharing knowledge.

IPSA library, CEPT library for providing with books and internet access.

Prof Bakul Jani, Ar. Devang Parekh, Ar. Hitesh Changela, Mr. Kiran Vaghela, Ar. Satprem Maini, Ar. Dharmesh Jadeja for their valuable inputs and discussions related to the topic.

I was able to proceed in my topic because of the valuable time given by the Architects, engineers, labourers and contractors with whom i had discussions related to my questionnaire.

Thanks to owners of earth buildings in auroville and Kutch who co-ordinated well and helped to study and measure draw their respective buildings.

To batch 2005-this consists of all my friends who have experienced architecture academics with me, sharing all their fun and knowledge and for being together in a new city away from the family.

I would also like to thank all those who in some way or the other helped me in every stage of my life till now and finally to the person who is reading this and (hopefully going to read) further. I hope the study become useful and serve the purpose for which it is been read.

Contents

PREFACE 1

1. INTRODUCTION 2-7

1.1 Aim/objectives

1.2 Methodology

1.3 Necessity of research on earth construction

1.4 Scope and limitations

2. EARTH CONSTRUCTION TECHNIQUES 8-22

2.1 Earth architecture of world

2.2 Earth as a building material

2.3 Traditional earth construction techniques

2.4 Contemporary earth construction techniques (illustrated with figures) 23-32

2.4(a) Cob

2.4(b) Adobe

2.4(c) compressed stabilised earth blocks

2.4(d) Wattle and daub

2.4(e) Rammed earth

3. INNOVATIONS IN EARTH CONSTRUCTION 33-62

3.1 Introduction

3.2 Analytical charts showing solutions through:

3.2(a) Primary case studies

3.2(b) Designing

3.3(c) Construction

3.4(d) Maintenance

3.5(e) Demolition/Reuse

4. CONCLUSIONS 63-64

APPENDIX 65-118

1. Interviews and discussions with subject experts 65-70

2. Analysis of soil type 71-72

3. Traditional construction drawings 73-75

4. CSEB and stabilized rammed earth 76-93

5. Built examples 94-118

Afterword-the future 119

Glossary 120

Image credits 121

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Preface

Currently it is estimated that one half of the world's population, approximately three billion people on six

continents live or work in buildings constructed of earth. It is evaluated that about 1.7 billion people of the world‟s

population live in earthen houses: About 50 % of the population in developing countries, and at least 20% of urban

and suburban populations.

And while the vast legacy of traditional and vernacular earthen construction has been

widely discussed, little attention has been paid to the contemporary tradition of earth architecture.

- Ronal Rael-Earth Architecture

This paper is focusing particularly on the innovations done in last few years in the field of earth construction that

can lead to its better use as a building material. This thesis deals with earth as a building material, and provides a

survey of all of its applications and construction techniques while explaining its specific qualities and the

possibilities of optimising them. It provides the new, creative uses of the oldest building material on the planet.

Many assume that it's only used for housing in poor rural areas—but there are examples of bungalows, offices,

apartments and institutions that are made of earth. It's also assumed that earth is a fragile, ephemeral material, while

in reality some of the oldest extant buildings on the planet are made of earth. Earth buildings are often thought of as

pre-modern or backward. With help of discussions with the subject experts, drawings and images, this paper

showcases the beauty and simplicity of one of humankind's most evolved and sophisticated building technologies.

Mud (wet, soft earth) is a natural material which after exploration can be used just the way other

contemporary materials are used. A person, who started using glass, would not have made a skyscraper at first go.

After years of experiments designers and engineers might have used it as skin for skyscrapers. If there are

advantages about a certain material then there are limitations and disadvantages too, that can be solved by studies,

experiments and application of that material in different ways. Just because mud was used traditionally doesn‘t

mean it cannot be used today in contemporary architecture, it has risen from those mud toys to mud huts and now

to institutions, bungalows and multi-storeys. Mud is no more a material known for construction of ‗kuccha‘ houses

.While shrinkage, erosion and mechanical damage can affect earth construction like any other building material,

preventative measures can be taken for innovating the material itself rather than constructing with high cost,

imported materials.

Appendix 1 is the basis of development of this paper. The introductory chapter provides with a short survey

on the history of earth architecture. In other following chapters it describes the contemporary and future roles of

earth as a building material, and lists all of the significant characteristics that distinguish earth from common

industrialised building materials. The thesis final appendices titled ‗built examples‘ are earth buildings from

various regions of the world. These constructions demonstrate the impressive versatility of earth architecture and

the many different uses of the building material earth.

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Introduction

“Here, for years, for centuries, the peasant had wisely and quietly exploited the obvious building material, while we, with our modern school-learned ideas, never dreamed of using such a ludicrous substance as mud for so serious a creation as a house. But why not? Certainly, the peasant‟s houses might be cramped, dark, dirty, and inconvenient, but this is no fault of the mud brick. There was nothing that could not be put right by good design and a broom.”

-Hassan Fathy (1973: 4)

AIM

 The aim is to study the traditional earth construction techniques and earth construction techniques of contemporary architecture, stating problems with the techniques as why they make earth architecture undesirable for present client and stating solutions from the case studies of contemporary earth buildings that show innovations made in traditional techniques and show potentials and possibilities of earth construction so that the present man desires it just like other contemporary architectural styles and materials.

OBJECTIVES

 To understand ideology of earth materials.

 To study the various earth construction techniques.

 To analyse the contemporary earth architecture in respect to its construction.

 To review the possible innovative earth construction methods and study the minor details that can help improve its use.

 To review the appropriateness of the earth as building material in present scenario.

METHODOLOGY

 Understanding traditional earth construction techniques(internet, books, people)  Gathering secondary data(internet, books, previous thesis done by others)  Preparing research questionnaire

 Conducting interviews with the experts(architects, contractors/engineers, skilled labourers) of the subject

 Identifying problems with the designing, methods, construction techniques and maintenance related to earth architecture through those interviews and related case studies.

 Doing case studies to understand the contemporary explorations and innovations to overcome those problems and show potentials of earth architecture.

 Compilation of data, chapter writing and deriving conclusions

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NECESSITY OF RESEARCH ON EARTH CONSTRUCTION

 To get knowledge about the material and promote earth construction  To create awareness about earth construction

 To learn the potentials of earth building process (designing, construction, maintenance, demolition/ re-use)

SCOPE AND LIMITATIONS

Chart 1

There are various aspects of earth architecture, but the focus in this thesis is to study the earth construction and innovations in it, to study the problems that earth as a building material has and find the solutions through the recent innovations in the material and its applications.

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Earth construction techniques

“Our modern, advanced scientific minds should know how to assess the merits and demerits of historic and factual evidence of the way people who have lived in a particular setting and climate, have coped with the problems which are still inevitably ours today. To brush aside all this demonstration and evidence as old-fashioned and therefore useless is extremely foolish. Having made our assessment we would show ourselves capable of adopting the lessons we have learned (negative or positive, they are of equal importance) to our current living habits and the currently available building materials at our disposal. Along with this we should remind ourselves that it is not „advancement‟ or „development‟ or „progress‟ to indulge in modern building materials and techniques at tremendous expenses and to no good effect when there is no justification or reason for their use, instead of older, simpler, inexpensive methods. ”

- Laurie Baker (life, work and writings), page 23

EARTH ARCHITECTURE OF WORLD

Down through the ages, people have been using raw earth for building their living spaces. Every single continent, and nearly every country, possesses a rich heritage of earthen buildings. From the roof of the world in Tibet, or the Andes Mountains in Peru, to the Nile‘s shore in Egypt or the fertile valleys of China, many are the examples of earth as a building material. Earth construction techniques have been known for over 9000 years. Mud brick (adobe) houses dating from 8000 to 6000 BC have been discovered in Russian Turkestan (Pumpelly, 1908). Rammed earth foundations dating from ca. 5000 BC have been discovered in Assyria. Earth was used as the building material in all ancient cultures, not only for homes, but for religious buildings as well. Vaults in the Temple of Ramses II at Gourna, Egypt, built from mud bricks 3200 years ago. The citadel of Bam in Iran, parts of which are ca. 2500 years old; a fortified city in the Draa valley in Morocco, which is around 250 years old. The 4000-year-old Great Wall of China was originally built solely of rammed earth; only a later covering of stones and bricks gave it the appearance of a stone wall. The core of the Sun Pyramid in Teotihuacan, Mexico, built between the 300 and 900 AD, consists of approximately 2 million tons of rammed earth.

The world‘s oldest earthen building still standing is about 3,300 years old. In India, the oldest earthen building is Tabo Monastery, in Spiti valley –Himachal Pradesh. It was also built with adobe and has withstood Himalayan winters since 996 AD.

1.

1. Earth construction areas of the world

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3. Dejenne Mosque of Mali, Mopti 4. Tabo monastery, India 996 AD

5. Archaeological site of Mari Syria – Funded in 2800BC 6. Taos pueblo, New Mexico

7. Great Wall of China

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8. A panoramic view for desert vernacular mud brick architecture in Dakhla oasis, Egypt. 9. Citadel of bam, Iran, before the earthquake

10. Ramasseum, Egypt ~ 1300 BC 11. Fortified city, Draa valley, Morocco 12. Bazaar, Sirdjan, Iran

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EARTH AS A BUILDING MATERIAL

 Earth comes from the disintegration of the parent rock. This rock disintegrates into mineral particles with varying dimensions ranging from pebbles to clayey dust.

In the upper layer these particles are mixed with organic material from the decomposition of the living World.

This ―organic‖ soil is reserved for agriculture.

The other layers are used for construction.

Sand Silt

Stones Gravel Clay

Inert

Active Organic

material

Plasticity Cohesiveness Compatibility

Soil skeleton _Binder

Chart 2

There are several different types of earth according to the quantities of the following components: GRAVELLY EARTH – SANDY EARTH – SILTY EARTH – CLAYEY EARTH

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provided in chapter three and in the appendix containing discussions with the experts, and through the case studies.

The parts highlighted in the above chart are the main construction techniques used in contemporary earth construction and are studied in detail and explained in the next part of ‗contemporary earth construction techniques‘

TRADITIONAL EARTH TECHNIQUES

12 earth construction techniques Chart 3

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 The earth is dug out to create shelters. In most of cases dwellings are dug out in soft soils, tuffs, porous lava in areas with hot and dry climate.

 The horizontal dug out create caves on the side of the hills, which are accessed by staircases and galleries.

 The vertical dug out are created in areas such as plateaus or plains. A kind of open courtyard is dug out a few meters deep and then room are dug out like caves on the side of this courtyard. Access to the dwelling is done by a staircase, often very steep.

 Beautiful examples are found in China, in the provinces of Hunnan, Shanxi, and Gansu, where more than 10 million people live in homes dug out of the loess layer. In Tunisia too, one can find interesting achievements.

 In Turkey, Cappadocia show exceptional creations where people combined vertical and horizontal dug out.

EARTH DUG OUT

13. 14.

15. 16.

13. Tunisia, Matmata (Photo CRATerre EAG

14. China, Nxiang region – Han Jia Bao (Photo V. Dubourg 15. China, Nxiang region (Photo Chinese Society of Architecture) 16. China – Plan of dug out dwelling (Source unknown)

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.

18. India, Panaji – Ex Palace, 16th C.

19. Burkina Faso, Quarry of Kari (Photo CRATerre/EAG) 20. India, Kerala, Near Soranad – Shaping a plinthite block 21. India, Orissa, Near Narangarh – Cutting petroplinthite by hand 22. India, Goa – Basilica Bom Jesus, end 16th century

 In areas where the soil was cohesive and contained concretions of carbonates (a natural chemical which give cohesion) the soil was cut in the shape of blocks and used like bricks or stones. Such examples are found typically in tropical areas where lateritic soils give a wonderful building material.

 Lateritic soils can be found in two natural states:

- Soft soils, which will harden when exposed to air due to chemical reaction of the soil constituent with the air. Such soils can be found on the west coast of India, from Kerala to Goa.

- Hard crust which was long ago in soil form and has already hardened through the ages. Burkina Faso in Africa and Orissa in India show wonderful examples of such soils and blocks.

 In areas where the soil is not cohesive enough, people have used topsoil and grass to create blocks which were stacked fresh upon each other. This method has been used a lot in England, where it has been named sod.

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25. 26. 23. USA, California, Cal-Earth – Eco-domes

24. Inside view from the dome 25. Exterior view without plaster

26. USA, California, Cal-Earth – Plastering the Eco-dome

 This method was developed from the bunkers made by the military.  The basic construction method began by digging a trench.

 Rows of woven bags (or tubes) are filled with available inorganic material.

 After the foundation is laid, each successive layer will have one or more strands of barbed wire placed on top.

 The weight of this earth-filled bag pushes down on the barbed wire strands, locking the bag in place on the row below.  The most popular type of bag is made of woven polypropylene.

 Organic natural materials such as hemp, other natural-fibre bags (like ―gunny sacks‖) can be used.

 Humid soil was traditionally poured into wooden lattice works. Thus, it gave some thermal mass to light structures as well as some acoustic insulation.

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 Soil has been traditionally used to cover roofs in different parts of the world. In arid climates, either very hot or very cold, it regulates the inside temperature, due to heavy thermal mass.

 In Scandinavia, the earth to cover roofs was taken with grass, so as to hold the soil and give cohesion to it through their roots. This method also gave more thermal mass and allowed the inside temperature to be more even.

 In Nordic countries but also in the Himalayas regions, waterproofing was done long ago with the bark of birch trees. The bark peeled from the tree was very thin and it was applied in several layers to get a waterproof effect.

 Nowadays, waterproofing is done with PVC or bitumen sheets. Green roofs are today a modern development of the technique of covered earth. Green roofs, also known as vegetated roof covers or eco-roofs are multi-beneficial structural components that help to mitigate the effects of urbanization on water quality by filtering, absorbing or detaining rainfall.

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31. 32.

33. 34. 31. Morocco – Horizontal rammed earth construction

32. Morocco – House

33. China, Fujian Province – Village / house of Hakka‟s clan

34. France, Dauphine – Château, 19th century

 Rammed earth, also known in French as pisé de Terre or simply pisé has been used since ages worldwide like many other earth techniques.

 Rammed earth is an ancient earth building technique. It is really quite similar to adobe and cob techniques, in that the soil is mostly clay and sandy. The difference is that the material is compressed or tamped into place, usually with forms that create very flat vertical surfaces.

 The earth is mixed thoroughly with water to get a homogeneous humid mix. This humid earth is poured in a form in thin layers and then rammed to increase its density. The increase of density increases the compressive strength and the water resistance.

 Ramming was traditionally done by hand.

 The worldwide tradition of rammed earth construction has shown that it is possible to achieve long lasting and majestic buildings from single to multi storey. Wonderful heritage can be found in countries such as France, Spain, Morocco, China, and all over the Himalayan area. One can see numerous and wonderful examples with all kinds of buildings:

 Farms, or rural houses, chateaux and apartments in Europe  Entire villages in North Africa

 Parts of the great wall of China

 Buildings in most of the Himalayan regions of Tibet, Bhutan, Nepal, Ladakh  Widespread examples in South America

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35. India, Ladakh – Spituk Gompa 36. Morocco village

37. Traditional rammed earth 38. Rammed earth Building in Yaman

Soil identification

 Knowing that the best soil for rammed earth is preferably sandy or gravely rather than clayey, one should take a lot of care about the clay content.

 Worldwide, the skill and knowledge of people has led them to choose rammed earth when the soil was more sandy or gravely. When the local soil was more silty or clayey they chose other techniques like Adobe, Cob or Wattle and Daub.

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40. Togo – Granary

41. Niger – Granaries

42. Cameron – Mousgoum hut (Photo Gert Chesi) 43. Cameron – Granaries

 Direct shaping makes use of plastic earth and does not require a mould or formwork.  Plastic earth is shaped, as a potter would do it.

 The quality of the soil, its preparation and the water consistency are important to be known.

 This technique presents the advantage to use minimal and very simple tools, and to use a minimum of labour which is necessarily skilled. This technique allows very fluid architecture with a great variety.

 The limitation of this technique is mostly the know-how for the soil quality and controlling the shrinkage when the wall dries.

 This technique has been and is still used a lot in Africa, in the Sahel as well as in equatorial regions. Beautiful examples can be seen in Cameroon where shaped earth has been used for houses and granaries.

 Natural stabilisers have been use traditionally in countries like Nigeria and Ghana.

 They either used the juice of plants and vegetables or boiled seeds to prepare natural glues which were added to the soil.

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 Cob construction uses sand, clay and straw. Elongated eggs are made of this mix and stacked layer wise. Mixed well this special mud is applied to the foundation in continuing layers. Each layer must dry so that it can support the next, and the wall is tapered in as you build up. When it is dry, the walls are very hard and load bearing. The roof is built directly on to the walls, as the walls themselves are the support structure.

 This technique has been used a lot long ago in Europe, where it was named cob in England and bauge in France.  This technique is still used a lot in Africa, India and in Saudi Arabia, where beautiful examples can be seen.

 The most beautiful examples are encountered in Yemen with Shibam. This old historic capital of Southern Yemen has been named ―The Manhattan of the Desert‖.

44. Saudi Arabia – Najran Palace(Photo M. Abdul-Aziz) 45. Southern Yemen, Shibam (Photo Patrick Meyer) 46. Mali, North of Mopti – Mosque(Photo Gert Chesi) 47. Saudi Arabia – Najran Palace (Photo H. Houben)

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48. India, Ladakh - Shey Palace 17th Century

49. Iran, Meiboud – Office of ICHO

50. Egypt, Baris - Market by Hassan Fathy 51. Bazaar, Sirdjan, Iran

ADOBE

 Sun dried clay brick, named Adobe, is undoubtedly one of the oldest building materials used by mankind: The oldest identified adobes were produced around 9,000 BC at Dja‟ De El Mughara in Syria.

 Adobes are made of thick malleable mud, often added with straw. After being cast they are left to dry under sun. They are traditionally either hand shaped or shaped in parallel piped wooden moulds.

 This technique has been used all over the world since memorial times, as can been seen on various hieroglyphs and Egyptian scriptures.

 The oldest samples known were found on the site of Jericho, in the Jordan Valley, in Mesopotamia. They date from around 8000 BC and they were hand shaped. They looked like an elongated loaf. Fingerprints of the craftsmen who did them are still visible on some of them.

 In Peru the hand shaped adobes were long ago conical. In the Middle East they were at a time hemispherical and humpbacked. In India the archaeological site of Chitradurga in Karnataka state shows also hand shaped adobe of the 15th century. They were like quadrangular loafs.

 Today one can still find hand shaped bricks in Africa, in countries like Nigeria or Niger where they are called Tubali.  Adobe production has been industrialised in Western USA. Several states in USA have codified adobe making and its

construction.

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52. Burkina Faso, Ouagadougou (Photo J. Joffroy) 53. Burkina Faso, Ouagadougou (Photo J. Joffroy)

54. France (Photo Unknown)

 The earth extrusion technique has been used since a long while in the fired brick industry. Stabilised earth, at a plastic state, is as well extruded through a machine which gives the desired shape.

 The blocks are often hollow and are cut to the desired length. This technique of stabilised extruded earth was developed in the 20th century.

 Compared to the brick extrusion in the fired brick industry, stabilised extruded earth bricks show a major inconvenient: the soil required for stabilised earth is much sandier than the one for fired earth. Thus the soil is more abrasive and the machines get damaged at a much faster rate.

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55. 56.

57. 58.

55. Traditional wattle and daub 56. Somalia, Genale - Village huts 57. France, Alsace – House

58. France, Bresse, Saint Triviers de Court - Farm house

 _{Wattle and daub method is an old and common method of building mud structures.}  _{There bamboo and cane frame structure support the roof.}

 Mud is plastered over this mesh of bamboo cane and straws.

 Due to excessive rainfall the wattle and daub structures gets washed off.

 _{However, the mesh of cane or split bamboo remains intact and after the heavy rain is over the mud is plastered on} again.

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59. 60.

61. 62.

60. Belgium, Leuven (Photo H. Houben)

61. Germany, Darmstadt (Photo F. Volhard)

62. Germany, Darmstadt (Photo F. Volhard)

 Very clayey soil, in a liquid state, is poured on straw, which has been chopped to the desired length.

 The mix is generally tampered afterwards into forms. These walls are not load-bearing: they are light, have a very high thermal insulation value and must be built in a wooden structure.

 It was traditionally used in Germany and was re-used for reconstruction after the 2nd world war. It is mostly known with the name Straw clay.

 Straw clay can be used as a filler wall, formed between a wooden structure or as prefabricated blocks.

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 The soil, in a liquid state, is poured like concrete into formworks. The soil characteristics must be very sandy or gravely and should be stabilised.

 This technique is a new development and is very seldom used. The reason is that the high water content of the soil will induce a lot of shrinkage when it will dry. Thus the wall will crack.

 The following chart shows how blocks are cut after the earth is poured in a blocked formworks.

 Also, directly the formwork is arranged on the wall through vertical bamboo supports and then liquid earth is poured into the formworks.

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64. India, Auroville - Termite nest 65. India, Auroville - Termite nest

66. Burkina Faso, Toussiana - Termite hill

 Termites can be considered as the best earth builders. Building with earth is inherent to their nature. Termites stabilise

the soil with their saliva. The latter is sticky, as it is issued for the digestion of cellulose, and it binds the grains of soil.

 This allows them to build such wonders. Termites can also be considered as the best air conditioners. Their hills are

meant to regulate temperature and moisture, in order to allow them to live.

 Constructed out of local dirt, sticks, and sometimes even faces, their saliva is used to form the bonding agent. The

interior of the mound includes a series of tunnels and chambers with the nest located at the bottom. Various openings and passageways are cleverly placed throughout to assist in capturing and drawing in cool air while pushing warm air up and out of the mound. By using this careful layout, the termites can regulate the temperature through blocking or opening passageways within the mound to control the temperature to their needs.

- Laura Schultz

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CONTEMPORARY EARTH CONSTRUCTION TECHNIQUES

 The techniques mentioned till now included overall all the techniques of earth construction and were explained briefly.  Nowadays out of all those techniques only few of them are used with their innovative applications and manufacturing.

chart 5

 Cob  Adobe

 Wattle and daub

 Compressed stabilised earth blocks(refer appendix, part 3)  Rammed earth

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68. Stacking the moulds

69. Levelling and trimming after every stage to prevent Unlevelled walls from building up and drying out 70. Smoothening the sides

71. Arrangement of shuttering for openings 72. Layering the cob strips

73. Plastering the cob wall 74. Thatch roof cob house 75. Flat roof cob house

 With only a little water to form a very stiff mud, a large Lump is roughly moulded into the shape of a huge elongated egg.

 The usual size is anything between 12 to 18-inches, (30 to 40 cm) long and about 6 inches (15 cm) in diameter.

 A row of these cobs of mud are laid neatly side by side, preferably somewhat pressed together. Then another row of cobs is laid on top.

 When three or four courses have been laid, one above the other, the sides are smoothened over so that the holes and cracks disappear.

 Openings for doors and windows are a problem, which can be solved by using temporary vertical planks or shuttering.  Another very simple shuttering for openings is to use empty kerosene tins.

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Adobes are made of thick malleable mud, often added with straw.

76. Stem wall on top of foundation

77. Anchoring the window frames and door frames to ground by wooden logs. 78. Roof logs attached to cob walls through wooden rafters

79. Thatched roof detail

76. 77.

78. 79.

 While in the case of earth block work, dry elements are built up with mortar joints, no mortar is used with wet loam work. Plastic loam is bound simply by ramming, beating, pressing or throwing.

 Some detailing of cob construction is explained below.

 Stone set on wet concrete to bond the cobs better from the base.  Top of the stem wall is irregular to provide „tooth‟ for cob.

 To prevent lifting in strong winds, anchoring roof to the cob walls by wooden rafters with galvanized wire to the wall.

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80.

ADOBE

80. Typical profile of the elements making up a cob and thatch

building.(illustration from building with cob: a step by step guide, by Adam Weismann and Katy Bryce, green books

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 Adobes are made either by filling moulds with a pasty loam mixture or by throwing moist lumps of earth into them.  After being cast they are left to dry under sun. They are traditionally either hand shaped or shaped in parallel piped

wooden moulds.

 Different types of moulds can be used; some of these are shown below.

 They are usually made from timber. The throwing technique is commonly used in all developing countries.

 Here, a sandy loam is mixed with water, and cut straw is usually added and the whole formed into a paste that is thrown into wooden moulds.

 The greater the force with which the loam is thrown, the better its compaction and dry strength. The surface is smoothed by hand or by a timber piece, trowel or wire.

 One person can produce about 300 blocks per day (including preparation of mix, transportation and stacking.  The disadvantage is that the blocks are usually stabilised with 4% to 8% cement content in order to endow them with

sufficient strength.

 This is necessary because of the absence of either sufficient water or adequate dynamic impact capable of significantly activating the binding forces of the clay minerals. Without cement, pressed blocks usually have dry a compressive strength lower than that of handmade adobes.

 Another disadvantage of such presses is that the soil mix must be kept at a constant level of moisture and composition.  If compositions vary, then both the volume of the material to be filled and the pressure changes.

 This leads to variations in the heights and strengths of the blocks.

 Fully automatic block-making presses can produce 1500 to 4000 blocks daily. However, they require large investments and may be difficult to maintain, especially in developing countries.

 To assure even loam consistencies, such machines often require separate crushers and mixers.

 Fully automatic presses are only economical if they have long lives, are utilised extensively on a daily basis, and if raw material of even consistency is available locally and in sufficient quantities.

81.

EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario

81. Timber moulds for adobes

82. Pouring earth mix into the manually operated press

83. Compacting the mix

84. Taking out block from the press 85. CINVA press

86-88 Making adobes in Ecuador

28

29

 This type of wattle and daub is a more modern version of traditional wattle and daub and is the most widely used.

 It has sections of cane or bamboo poles fixed with wires and nails to a sawed wooden structure which enables a better finished assembly. Earth mix is applied on this assembly and then finishes are applied to the wall surfaces.

 The prefabricated panel is a sawed wooden frame, filled with interwoven cane or bamboo battens, inserted in such a way that they are self-anchoring. After being assembled these panels are walls which will be plastered with earth and straw mortar with an initial layer and then a thin finishing layer. The advantage of prefabricated panels is that they enable the panels and the structure that will carry them in the wall to be made at the same time, thus reducing assembly time.

90. 91.

92. 93. 81. Corner junctions

82. Detail structure of the wall 83. Detail of cane fastening 84. Elevation of the wall

30

94. 95. 96. 97. 98. 99. 100. 101. 102. AOBE

94. T o set the columns use a plumb to make sure they are vertical, hold them temporarily with braces.

95. Always cut cane after knots.

96. The poles are fastened with a flexible material, such as galvanised wire or treated plant fibre

97. After defining the position of the vertical poles fix them. If you use hollow concrete blocks these can be taken advantage of. 98. Detail of connection between the corner column and the horizontal canes.

99. After justalling all the vertical poles, and before fixing the horizontal ones, the fasteners should be fixed. 100. Detail of join between vertical and horizontal poles

101. After fitting the horizontal poles at a height of up to 50 cm it is advisable to first fill the columns with wattle and daub mortar followed by the walls. The separation between the horizontal bars should be between 6cm and 8cm.

102. Detail of covering of iron ring (diameter 1/4"), with concrete mortar to make the column rigid.

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 After being excavated, the soil is thoroughly sieved, to break the lumps and make it lighter. Big rocks should be removed but some stones could be kept. If the natural soil is too dry, it should moistened and mixed so as to get a uniform humid mix.

 This method has developed from the cob wall so as to standardize or regularize the thickness of the wall.  It is also an attempt to increase the strength of the wall by ramming it.

 Two parallel planks are held firmly apart by metal rods and clips or bolts, or by small crosspieces of wood.  Stiff mud is thrown in between these two planks and rammed down with either a wooden or metal ramrod.  When one section is completed and hard, the two boards are moved along and the process is repeated.  The two planks are then raised up and a second course of rammed earth is repeated over the first.  Two techniques have traditionally been developed. They used either horizontal or vertical formworks.

 The horizontal technique was used in many parts of the world. Strips of walls were built horizontally and their height varied from 30 to 90 cm.

 The formwork consisted of 2 wooden panels held together with wooden clamps and keys, which were tightened with ropes. Once one portion of a wall was completed, the formwork is immediately dismantled and moved further along.  Humid soil was evenly poured into the formwork to get a regular course of about 12-15 cm thickness. Ramming was

traditionally done by hand.

 The soil is first rammed along the sides of the panels and the central portion of the wall is rammed immediately after that.

 Every course is rammed till the rammer hitting the soil gives a clear sharp sound and the rammer is not doing anymore marks on the course.

 Unstabilised soil is concentrated horizontally, and alignment is from layer to layer of wall.  Stabilized soil is concentrated vertically, and alignment is between forms.

 Openings for doors and windows within the wall are created with block outs.

 Corners are made stronger if created as one piece as opposed to solely having a joint between two.

 The specific construction of rammed earth consists of “lifts” or layers of earth poured into formwork at a depth of eight inches and then compacted to five inches. This creates a striated earthen wall.

 After the wall completely goes up and is cured (twenty eight to fifty-six day period) any fixtures may be added. The roof is tied into the wall, and window and doorframes are added. Fixings are buried deep within the wall to retain structural integrity. In addition, utilities and systems, determined before construction, may pass within the wall to a certain degree. The final part of the construction process is to apply a wall finish, if desired or required.

103. Boards and anchors for formwork 104. Spacers for connection of boards 105. Connected formwork

106. Manual compaction of mix between the boards

107. Anchoring the frames of doors with the ground and cross bracing them 108. Ramming first floor wall on top of a door

32

109. 110.

111.

 The approximate proportion of subsoil is thirty percent clay/silt to seventy percent sand/gravel. Water has a direct impact on the strength of finished walls, and depending on the soil mix, is eight to sixteen percent of the mix.

 An optional stabilizer may be added – four to twelve percent depending on conditions such as bonding strength of the clay, seismic activity, desired construction process, or desired wall proportions.

 Stabilizers include cement, lime, or pozzolan added to the mix.

 There are numerous field and laboratory tests to be run at all stages of the material gathering process, each to determine the specific mix peculiar to the site. These include density, compressive strength, bond strength, and erosion and wear resistance tests.

 Soil stabilization gave a great input to rammed earth as well as mechanization.  The traditional wooden rammer has been replaced by pneumatic rammers.

 Heavy wooden formworks evolved into light composite ones, made of plywood, wood and steel or sometimes aluminium.  Pneumatic rammers, dumpy loaders, mixers, ban conveyors, etc. allowed to build faster and get a better quality finish.  Structures are most of the time built with pier walls, meaning that walls are built up to their full height at once. This way of

building changed totally the design pattern of structures.

Moist Earth-Mixture of sand,

cement, gravel and clay Reinforced

plywood frame Rammer

Visible layers of compacted earth

EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario

109. USA, California, David Easton – Vertical form 110. Ramming with electrical rammer

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Innovations in earth construction

“CONTEXT- The necessity for speed was one of the big factors that contribute to that break with tradition. It probably took a thousand years for us to find out by trial and error how to make a mud wall impervious to rain and wind, another thousand years to learn how to keep termites out of it, and another two or three thousand to learn how to build multi-storied mud buildings.”

-Laurie Baker (life, work and writings), Page 19

“On the one hand, raw earth is still used … as basic shelter on a massive scale by hundreds of millions of people throughout the world. On the other hand, a new generation of architects and engineers, fascinated by the qualities of this highly ecological resource, is finally rediscovering and reasserting its value, modernising its technology and adapting raw earth construction to a broad range of modern applications:...” (2002:9).

-The series of articles by Detheir and Eaton appeared in the September 2003 issue of ByggKunst

 This chapter mainly tells about the problems associated with earth architecture and is divided into four parts according to the various stages of a building process:

1. Designing 2. Construction 3. Maintenance 4. Demolition/reuse

 Now, there are innovations, detailing and some necessary precautions that can overcome those problems, limitations and make earth construction as a viable system for building.

 Primary case studies include buildings seen and measure drawn (the required details) in Kutch and Auroville.

 According to the problems identified through the questionnaire and secondary case studies, there are solutions that are mentioned in the charts through primary case studies.

PRIMARY CASE STUDIES

Problem

Solution

• When building with earth, one should pay a lot of attention of the management of resources and raw materials. Topsoil should be scraped away, so as to be re-used for agriculture or gardens. Sieve the soil preferably in the quarry: the waste soil can be re-used on the spot to finalize the landscaping.

• One should always plan how the excavation would be used afterward. Design the quarry (area and depth) according to the future use of the hole. Dig according to the design requirements: steps or slope, deep holes or shallow excavation, etc.

• A proper management of the earth resources can create a new and harmonious balance between nature and the buildings.

• Auroville shows various possibilities for the use of quarries: as water harvesting ponds, waste water treatment ponds, pools, basement floors or shallow Biological wastewater treatment depressions which are used for landscape design, work or play areas, gardens, etc.

• Various stages of making blocks from raw materials o _Sieving o _Measuring o _{Dry mixing} o _{Humid mixing} o _Moulding o _{Initial curing} o _{First stacking} o _{Final curing} o _{Final stacking}

Related drawings

1. Process of formation of blocks/earth mix from raw materials for construction 2. Covered clay mixing area

3. Segregation of various raw materials through partitions 4. Quarry transformed into a wastewater treatment 5. Shallow excavation for making adobes

6. Quarry planned for a wastewater treatment and rainwater harvesting 7. Waste water treatment area

1. 2 . 6. 7. 3 . 5. 4 .

34

PRIMARY CASE STUDIES

Problem

Solution

The traditional wattle and daub approach does not have safeguards to ensure that the wall is plumb and this can result in structural weaknesses

especially when the technique is translated to larger buildings.

Refer Appendix 5 (case study 9)

Penetration of water from the roofs that caused water problems from the roof on inside spaces.

Refer Appendix 5 (case study 7) Thatched-earth tile roof

• The roof frame must be built strong enough to support the weight. The best earth tiles are made with stabilized soil

• Also, wooden strips or metal rods (called stringers) must be placed in the roof at close enough intervals so that each tile rests on two stringers, either directly or indirectly. • Tiles are often made with a lip or groove near the upper edge so that they will be

positioned securely on the stringers.

• Earth tile have also been used for roofs. They can be pressed in a block making machine by using fillers.

• They can also be of sun-dried adobe but in either case it is best to stabilize the earth. The tiles are placed on a wooden frame.

• The tiles should be 1 1½" to 2" thick and about 1' long. • Good sun-dried tiles are made with a thatch (or grass) "tail."

• The thatch tail helps prevent rain from eroding the block, and provides insulation for the inside of the house.

• The contemporary stick-frame construction cut costs and reduces raw material usage through the efficient use of wood cut into standardized sizes and designed geometrical patterns with infill of earth mix.

• The timber framework is braced for lateral-stability.This also leads to a wall which is structurally sound and plumb is maintained.

Related drawings

8. Wattle and daub on top of wall made of CSEB units. 9. Connection of truss with the wattle and daub timber frame. 10. Roof wall assembly

11. Hunnarshala, Bhuj(wattle and daub)

12. Hunnarshala, Bhuj(thatch roof) 13. Thatch roof supported on a steel

truss and CSEB walls

14. Connection of roof tiles with the wooden strips(stringers) 8. 9. 10. 14. 12. 11. 13.

35

PRIMARY CASE STUDIES

Problem

Solution

Flat slabs are not possible and so multi storey's cannot be made.

Formation of lintels by earth blocks

• CEB blocks were used to make vaults on top of CSEB walls and supported on concrete beams and a flat layer of kadappa stone was laid on top of the vaults leaving the side space on top of the dome hollow.

• Earth was used, from the first developments of Vikas, in all parts of the buildings, from foundations to roof.

• Including the basement, it is a four storey building. • Project Details – Vikas Apartments, Auroville • Architect: Satprem Maini

• Period of construction: 1992-1999

• Project Description: 23 residential apartments housing and common facilities. • Building Type: Residential

• Climate: Warm and Humid • Built in area: 1420 m2

• Owners/clients: Collective of clients

• Building Technologies: Earth and ferrocement

• Vikas apartment are built with stabilized rammed earth foundation (with five percent cement)

• CEB (compressed earth blocks) with five percent cement for walls vaults and domes. • Some walls have been made using rammed earth with five percent cement

• The soil for building has been extracted from the waste water treatment pond and the garden tank.

• while in the third apartment building with a basement floor, the excavated soil is used for building.

• Ferrocement roof channels have been used for some floors while doors and shelves are of ferrocement.

Related drawings

36

15. Vault and flat slab of kadappa stone with CEB tiles as flooring

16. Vikas apartment, Auroville(vault supporting flat slabs)

17. Vikas apartment, Auroville(3 storey's with basement)

PRIMARY CASE STUDIES

Problem

Solution

Flat slabs are not possible and so multi storey's cannot be made.

Hourdi roofing used in auroville earth institute to create flat earth slabs.

• The hourdi block produced by the Auram press 3000 is used to create floors and roofs. • These blocks rest either on reinforced concrete T beams or on ferrocement channels. • As these blocks are hollow they create roofs which are more comfortable under a hot

climate.

• The resistance of these blocks is extremely high.

• The series of these blocks is rested on the edges of ferrocement channels and then earth filling is done to make even surface on top surface which combines the channels with the blocks.

Related drawings

20. Adjusting hourdi blocks in between ferrocement channels 21. Casting an earth concrete: 1 cement: 2 soil: 3 sand: 4 gravel 22. Auroville earth institute, hourdi roofing

23. Vault structure on top of hourdi roofing

37

21. 20.

22.

PRIMARY CASE STUDIES

Problem

Solution

Aesthetics and

insulation pottery for insulation and aesthetics

• Pottery is a developed craft of kutch. To use clay items for construction was to find new ways of building methods.

• The clay plates and bowls are used for wall and roof insulation and pots as visual objects for design.

• The local convex circular clay plates are claded on the external wall for insulation. • Small holes are made in plates for ventilation and arranged in different designs and

patterns.

• The triangular spaces between them are filled with small mirrors for the reflection of heat. Thus, the entire surface of wall is taken care of heat insulation.

• This wall cladding and insulation work proceeds fast as the surface coverage of each plate is about 25cm diameter.

• Since it is a local material the cost of plate is low and the total item costs much less than conventional cladding methods.

• At the same time, it provides work for the potter who has to make about 5000 plates for one house.

• Clay tiles are also used in auroville and Bangalore inside the houses for improving the inner climate through use of clay pots and clay tiles in ceilings.

• Inverted bowls used for ceiling pattern. They also act as lamp fixtures lighting up the entire ceiling

Related drawings

38

filled with mirrors for reflecting heat

25. Clay bowls can also be used for wall insulation 26. Clay bowls as cladding for insulation, Kutch

27. Filler slabs( Mangalore tiles, Stabilized mud blocks) details 28. Mangalore tiled ceiling, Bangalore

Related drawings

39

30. Inverted bowls used for ceiling pattern. They also act as lamp fixtures lighting up the entire ceiling(wall section and view)

31. Use of inverted bowls, Auroville (creativity apartment)

32. Use of clay bowls with all fixtures for the ceiling , Auroville(creativity) 33. Use of clay bowls(whole inside), Bangalore

34. Inverted clay pots used in curvilinear ceiling 35. Inner view of the house

PRIMARY CASE STUDIES

Problem

Solution

Wood doesn‟t adhere with the earth walls and mostly create gaps between the wall and the frame of the window.

There is an alternative where pivoted windows are used where there is no need of wooden frames and so the windows are directly attached by pivots to the two sides of the walls.

Flat Earth flooring Rammed earth houses can be built in one of three basic ways. Individual, rammed earth bricks can be formed and used with standard building techniques; in fact, such bricks may be used to form the floors in a rammed earth house built with other techniques.

Oxide flooring is used now adays by which various colored flooring can be produced from earth techniques.

Rammed earth flooring with covering of wooden blocks and strips are also a good solution to achieve flat floors from earth.

Possibilities of large and various types of openings.

CSEB walls and the introduction of stabilized walls for rammed earth has given more easy ways of making large openings of various shapes and sizes.

PRIMARY CASE STUDIES

40

37. Sketches by Laurie baker showing window type

38. Pivoted window(Hunnarshala, Bhuj)

39. Oxide flooring (Hunnarshala, Bhuj)

40. Some supporting sketches from book building with earth showing rammed floorings 41. Window type(Hiralaxmi craft

park, Bhujodi)

42. Window type(Hunnarshala, Bhuj)

43. Various window types shown through sketches and pictures(Hunnarshala, Bhuj)

PRIMARY CASE STUDIES

Problem

Solution

Formation of organic shapes

and single roofed buildings. Cob is the technique that gives opportunity to form organic shapes.Now adays there are formwork for curved walls too and so the possibilities of shapes is more.

The plasticity of loam allows not only for the building of exterior walls, ceilings and floors but also of built-in furniture.

For this, loam elements when still wet are particularly suitable as they can be given a great variety of shapes; they also open up new aesthetic possibilities.

Related drawings

41

44-46. Auromodele houses showing some designs that can be done in earth.

47. Some sketches from book „architecture of Kutch‟ showing curvilinear designs developed from traditional bhungas 48. Shaam-e-sarhad resort(hodka,

banni) showing curvilinear shaped sitiing area

49. Shaa-e-sarhad (hodko, banni) showing single roofed spaces 50. Chintan organic farm(bhujodi)

showing single roof made of thatch with spaces segregated by walls.

PRIMARY CASE STUDIES

Problem

Solution

Vaults and domes of earth masonry requires skill labour .

Nubian vaults

With the Nubian vault technique, used for centuries in Upper Egypt, vaults can be built without any formwork by using reclining arches made of adobe.

Refer appendix 5 (case study of Delhi office)

After studying examples from Hassan Fathy and Nadir Khali, Ray Meeker moved to Pondicherry India. Using local materials of mud bricks, Meeker constructed a house by forming a central dome surrounded by four Nubian vaults. To harden the mud, Meeker turned the house into a kiln and fired the interior for four and a half days. To offset labour costs, clay pots, tiles and extra bricks were also fired in the structure to be sold. The term Agni Jata is used for this process; it means „fire burned‟.

In order to avoid the disadvantages of Nubian dome technology, a new technique for making domes using a rotational guide was developed at the BRL. With this technique, the structurally optimal geometry of the dome can be achieved without formwork.

The rotational guide has a right-angled head into which the blocks are placed. This angle can be moved on a curved metal T-section bent to shape. This T-section is fixed to a rotating arm, which is in turn fixed to a vertical post.

Related drawings

42

52. Firing the raw mud bricks and creating the building itself as kiln

53. Plastered and completed house 54. Vault created by Nubian vault process 55. Foundation and plinth layer completed 56. The four stages showing process of creating a

vault without formwork derived from Nubian technique.

BUILDING PROCESS - designing

Problem

Solution

To choose earth construction for the project.

To design appropriate earth building.

Some of the problems are listed below:

Factors to be kept in mind while designing earth building that can overcome the surface and structural defects:

• Wall thickness • Spanning members

• Which technique to be used for construction • Number of storey's

• Corner junctions

• Joineries and detailing to avoid water and termite penetration

• Water is a major agent of decay for earth walls. Therefore, codes and other publications generally recommend not placing plumbing within earthen features

To convince the client for earth

Construction.

Finalization of design with the client

• By showing the possible options and benefits of earth construction and some good examples of already made earth buildings.

• By showing the detailing that are done to overcome the issues related to water and insects, shrinkage cracks and stating the technique that is to be used.

• Showing the benefits related to climate and indoor temperature by using earth walls for building.

• Material aesthetic benefits and also showing examples of buildings already constructed out of earth.

Factors to be seen before choosing earth as a construction material

• Availability of raw materials- in the proximity of 20 kms is considered viable • Climate-mostly everywhere on each an every continent except Antarctica

because of unavailability of raw materials.

• Local labour- training minimum of 12 to 15 people is must for good earth construction.

• Getting knowledge about the material thoroughly through books and resource people.

Surface defects include (cracks; flakes; blistering;

peeling; loss of adhesion; and boniness.)

Maintenance & Repairs Structural defects include

water borne erosion of wall; freeze-thaw heave of wall; low level erosion at base of wall;

structural cracking (settlement, overload);

bulging;

abrasion damage; and rat runs and animal holes. - Pearson, 1992

Related drawings

1. Ring beam is lacking. 2. Lintels do not reach deeply

enough into masonry.

3. The distance between door and window is too small.

4. The distance between openings and wall corner is too small. 5. Plinth is lacking.

6. The window is too wide in proportion to its height.

7. The wall is too thin in relation to its height.

8. The quality of the mortar is too poor, the vertical joints are not totally filled, the horizontal joints are too thick (more than 15 mm). 9. The roof is too heavy.

10. The roof is not sufficiently fixed to the wall.

BUILDING PROCESS - designing

Problem

Solution

Termite and rodents penetrating the walls Roof connections with the wall base

• It is mostly because of the less thought given to the construction details at the initial stages of the design process.

• The joint of the wall with the plinth has to be carefully designed so that the rainwater can flow down unhindered without entering the joint between wall and plinth.

solution A is unacceptable because the extruded part of the plinth wont allow water to flow and will be collected there causing swelling and peeling of the plaster and wall.

Roof rafters should not rest directly on the earth wall, but instead on timber wall plates or beams as seen in A

Protection from rain

• One method of preventing rain from coming into contact with a loam wall is to provide it with a roof overhang.

• A sufficiently high plinth (30 to 50 cm) can protect from splashing rain. • Solutions B and C may be acceptable in areas with little rain.

• Solution D is common, whereas E and F show perfect designs for combating this problem.

• In B, an elastic sealant has been introduced between the beam and wall in order to provide sufficient tolerance for this shrinkage.

• In C, the structural system is separated from the wall, thereby allowing a greater vertical movement of the timber structure.

Related drawings