EARTH ARCHITECTUREInnovations 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, IndiaThe 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 asa prerequisite to the degree for which it has been submitted.It is understood that by this approval, the undersigned does not necessarily endorse orapprove of any statement made, opinion expressed or conclusion drawn there in, andapproves the study only for the above purpose, and satisfies him as to the requirementslaid down by the thesis committee.Thesis Title: EARTH ARCHITECTURE Innovations in earth construction and potential of earth architecture in contemporary scenarioName: Bhavi Vador Guide: Vishwanath KashikarRoll No: 3805 Signature: Date:
The dissertation is dedicated to my parents and to every individual who inspired me, guided me and helped me in my endeavours.
AcknowledgementInspirations 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 methis wonderful life by supporting me and making me an individual to stand out and face every difficulty that comes along theway of progress.I am very much thankful to my guide - Vishwanath Kashikar for guiding me, providing me sufficient and timely discussionsand 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 andthereby create a formwork for the dissertation. I would like to acknowledge not only those who directly contributed to thisdissertation, but also those whose moral support and confidence in me, whose companionship and discussions I have alwaysvalued.Ar. Nirav Vador and Ar. Kartik Bijlani for being a guide throughout, Dr.Tejal Gajra, Dhaval Vador and Jill Vador for askingme thousand times ‘when will you complete your thesis?’ .Nikitasha Vador for accompanying to auroville and making the tripmemorable 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 lowtimes and for being the best persons in my life.Anand Dave, Kanupriya Raniwala, Saumil Mewada, Bhaumik Modi, Pratik zaveri, Sridevi, Rosy for valuable inputs anddiscussions.Prabhulal Vora, Savita Vora, Pallavi aunty, Shailesh uncle, Parth Amin and the ‘shailvi’ home...for supporting and givingevery 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 fortheir 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 contractorswith 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 theirrespective buildings.To batch 2005-this consists of all my friends who have experienced architecture academics with me, sharing all their fun andknowledge 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 theperson who is reading this and (hopefully going to read) further. I hope the study become useful and serve the purpose forwhich it is been read.
Contents PREFACE 11. INTRODUCTION 2-7 1.1 Aim/objectives 1.2 Methodology 1.3 Necessity of research on earth construction 1.4 Scope and limitations2. 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 earth3. 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 Bibliography 122
PrefaceCurrently it is estimated that one half of the worlds population, approximately three billion people on sixcontinents live or work in buildings constructed of earth. It is evaluated that about 1.7 billion people of the world‟spopulation live in earthen houses: About 50 % of the population in developing countries, and at least 20% of urbanand suburban populations. And while the vast legacy of traditional and vernacular earthen construction has beenwidely discussed, little attention has been paid to the contemporary tradition of earth architecture. - Ronal Rael-Earth ArchitectureThis paper is focusing particularly on the innovations done in last few years in the field of earth construction thatcan lead to its better use as a building material. This thesis deals with earth as a building material, and provides asurvey of all of its applications and construction techniques while explaining its specific qualities and thepossibilities of optimising them. It provides the new, creative uses of the oldest building material on the planet.Many assume that its only used for housing in poor rural areas—but there are examples of bungalows, offices,apartments and institutions that are made of earth. Its also assumed that earth is a fragile, ephemeral material, whilein reality some of the oldest extant buildings on the planet are made of earth. Earth buildings are often thought of aspre-modern or backward. With help of discussions with the subject experts, drawings and images, this papershowcases the beauty and simplicity of one of humankinds most evolved and sophisticated building technologies. Mud (wet, soft earth) is a natural material which after exploration can be used just the way othercontemporary 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 areadvantages 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‘tmean it cannot be used today in contemporary architecture, it has risen from those mud toys to mud huts and nowto 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 surveyon the history of earth architecture. In other following chapters it describes the contemporary and future roles ofearth as a building material, and lists all of the significant characteristics that distinguish earth from commonindustrialised building materials. The thesis final appendices titled ‗built examples‘ are earth buildings fromvarious regions of the world. These constructions demonstrate the impressive versatility of earth architecture andthe many different uses of the building material earth. 1EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
Introduction“Here, for years, for centuries, the peasant had wisely and quietly exploited the obvious building material, while we, with ourmodern 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 mudbrick. 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 2 EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
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 LIMITATIONSChart 1There are various aspects of earth architecture, but the focus in this thesis is to study the earth construction and innovations init, to study the problems that earth as a building material has and find the solutions through the recent innovations in thematerial and its applications. 3EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
Earth construction techniques“Our modern, advanced scientific minds should know how to assess the merits and demerits of historic and factual evidence ofthe way people who have lived in a particular setting and climate, have coped with the problems which are still inevitably ourstoday. To brush aside all this demonstration and evidence as old-fashioned and therefore useless is extremely foolish. Havingmade our assessment we would show ourselves capable of adopting the lessons we have learned (negative or positive, they areof equal importance) to our current living habits and the currently available building materials at our disposal. Along with thiswe should remind ourselves that it is not „advancement‟ or „development‟ or „progress‟ to indulge in modern buildingmaterials 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 23EARTH ARCHITECTURE OF WORLDA MILLENNIA OLD TRADITIONDown through the ages, people have been using raw earth for building their living spaces. Every single continent, and nearlyevery country, possesses a rich heritage of earthen buildings. From the roof of the world in Tibet, or the Andes Mountains inPeru, 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 to6000 BC have been discovered in Russian Turkestan (Pumpelly, 1908). Rammed earth foundations dating from ca. 5000 BChave been discovered in Assyria. Earth was used as the building material in all ancient cultures, not only for homes, but forreligious buildings as well. Vaults in the Temple of Ramses II at Gourna, Egypt, built from mud bricks 3200 years ago. Thecitadel of Bam in Iran, parts of which are ca. 2500 years old; a fortified city in the Draa valley in Morocco, which is around250 years old. The 4000-year-old Great Wall of China was originally built solely of rammed earth; only a later covering ofstones and bricks gave it the appearance of a stone wall. The core of the Sun Pyramid in Teotihuacan, Mexico, built betweenthe 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 TaboMonastery, in Spiti valley –Himachal Pradesh. It was also built with adobe and has withstood Himalayan winters since 996AD.1.1. Earth construction areas of the world 4EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
2. 3.4. 5.6. 7.2. Ziggurat of Ur-in-Khaldea3. Dejenne Mosque of Mali, Mopti4. Tabo monastery, India 996 AD5. Archaeological site of Mari Syria – Funded in 2800BC6. Taos pueblo, New Mexico7. Great Wall of China 5EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
8.9. 10.11. 12. 8. A panoramic view for desert vernacular mud brick architecture in Dakhla oasis, Egypt. 9. Citadel of bam, Iran, before the earthquake10. Ramasseum, Egypt ~ 1300 BC11. Fortified city, Draa valley, Morocco12. Bazaar, Sirdjan, Iran 6EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
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. This ―organic‖ soil is reserved for agriculture. The other layers are used for In the upper layer these construction. particles are mixed with organic material from the decomposition of the living World. Active Organic material Inert Stones Gravel Sand Silt Clay Soil skeleton Binder Plasticity Cohesiveness Compatibility 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 7 EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
Note: These are some points for the overview of the material, more and detailed study of the material and its construction isprovided 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 arestudied in detail and explained in the next part of ‗contemporary earth construction techniques‘TRADITIONAL EARTH TECHNIQUES 12 earth construction techniquesChart 3 8 EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
EARTH DUG OUT 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. 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) 9EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
CUT EARTH 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. .17. 18. 19.20. 21. 22.17. Uruguay, Montevideo – Sod house (Photo H. Guillaud)18. India, Panaji – Ex Palace, 16th C.19. Burkina Faso, Quarry of Kari (Photo CRATerre/EAG)20. India, Kerala, Near Soranad – Shaping a plinthite block21. India, Orissa, Near Narangarh – Cutting petroplinthite by hand22. India, Goa – Basilica Bom Jesus, end 16th century 10EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
FILLED IN (EARTH BAG CONSTRUCTION) 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.23. 24.25. 26.23. USA, California, Cal-Earth – Eco-domes24. Inside view from the dome25. Exterior view without plaster26. USA, California, Cal-Earth – Plastering the Eco-dome 11EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
COVERED EARTH 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. 27. 28. 29. 30. 27. Canada, Factory 28. German, House 29. Germany, School 30. Germany, House 12EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
TRADITIONAL RAMMED EARTH 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 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 13EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
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. 35. 36. 37. 38. 35. India, Ladakh – Spituk Gompa 36. Morocco village 37. Traditional rammed earth 38. Rammed earth Building in Yaman 14EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
SHAPED EARTH 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. 39. 40. 41. 42. 43. 39. Nigeria, Near Kankeya – Granary 40. Togo – Granary 41. Niger – Granaries 42. Cameron – Mousgoum hut (Photo Gert Chesi) 43. Cameron – Granaries 15EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
STACKED EARTH (COB) 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. 45. 46. 47. 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) 16EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
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.48. 49.50. 51.48. India, Ladakh - Shey Palace 17th Century49. Iran, Meiboud – Office of ICHO50. Egypt, Baris - Market by Hassan Fathy51. Bazaar, Sirdjan, Iran 17EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
EXTRUDED EARTH 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. 52. 53. 54. 52. Burkina Faso, Ouagadougou (Photo J. Joffroy) 53. Burkina Faso, Ouagadougou (Photo J. Joffroy) 54. France (Photo Unknown) 18EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
WATTLE AND DAUB 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.55. 56.57. 58.55. Traditional wattle and daub56. Somalia, Genale - Village huts57. France, Alsace – House58. France, Bresse, Saint Triviers de Court - Farm house 19EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
FORMED EARTH (Straw Clay) 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. 59. 60. 61. 62. 59. Germany, Hessen, Gross Gerau (Photo F. Volhard) 60. Belgium, Leuven (Photo H. Houben) 61. Germany, Darmstadt (Photo F. Volhard) 62. Germany, Darmstadt (Photo F. Volhard) 20EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
POURED EARTH 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. Courtesy CRATerre -EAGChart 4 21EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
TERMITE WONDERS 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 63. 64. 65. 66. 63. India, Auroville - Termite hill 64. India, Auroville - Termite nest 65. India, Auroville - Termite nest 66. Burkina Faso, Toussiana - Termite hill 22EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
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 23EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
COB 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.67. 68. 69.70. 71. 72.73. 74. 75.67. Forming stiff mud and moulds68. Stacking the moulds69. Levelling and trimming after every stage to prevent Unlevelled walls from building up and drying out70. Smoothening the sides71. Arrangement of shuttering for openings72. Layering the cob strips73. Plastering the cob wall74. Thatch roof cob house75. Flat roof cob house 24EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
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.76. 77.78. 79. Adobes are made of thick malleable mud, often added with straw.76. Stem wall on top of foundation77. Anchoring the window frames and door frames to ground by wooden logs.78. Roof logs attached to cob walls through wooden rafters79. Thatched roof detail 25 EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
TYPICAL COB WALL SECTION DETAIL 80. 80. Typical profile of the elements making up a cob and thatch building.(illustration from building with cob: a step by step guide, by AdamADOBEWeismann and Katy Bryce, green books 26EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
ADOBE 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. 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 89. Removal of surplus Loam with a wire 81. 27EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
82. 83.84. 85.86. 87.88. 89. 28EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
WATTLE AND DAUB 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 junctions82. Detail structure of the wall83. Detail of cane fastening84. Elevation of the wall 29EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
Step by step construction94. 95. 96.97. 98. 99.100. 101. 102.94. 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 fibre97. 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 polesAOBE101. 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. 30EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
RAMMED EARTH 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. 104. 105.106. 107. 108.103. Boards and anchors for formwork104. Spacers for connection of boards105. Connected formwork106. Manual compaction of mix between the boards107. Anchoring the frames of doors with the ground and cross bracing them108. Ramming first floor wall on top of a door 31EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
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. 109. 110. Moist Earth-Mixture of sand, Reinforced Visible layers of cement, gravel and clay plywood frame Rammer compacted earth 111. 109. USA, California, David Easton – Vertical form 110. Ramming with electrical rammer 111. Compaction process 32 EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
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. 33EARTH ARCHITECTURE-Innovations in earth construction and potential of earth architecture in contemporary scenario
PRIMARY CASE STUDIESProblem SolutionManagement of • When building with earth, one should pay a lot of attention of the management of resourcesearth raw and raw materials. Topsoil should be scraped away, so as to be re-used for agriculture ormaterials and gardens. Sieve the soil preferably in the quarry: the waste soil can be re-used on the spot tomixing is a finalize the landscaping.complex • One should always plan how the excavation would be used afterward. Design the quarry (areaprocess. 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 1.2 3. .4 5..6. 7.1. Process of formation of blocks/earth mix from raw materials for construction2. Covered clay mixing area3. Segregation of various raw materials through partitions4. Quarry transformed into a wastewater treatment5. Shallow excavation for making adobes6. Quarry planned for a wastewater treatment and rainwater harvesting7. Waste water treatment area 34
PRIMARY CASE STUDIESProblem SolutionThe traditional • The contemporary stick-frame construction cut costs and reduces raw material usagewattle and daub through the efficient use of wood cut into standardized sizes and designed geometricalapproach does not patterns with infill of earth mix.have safeguards to • The timber framework is braced for lateral-stability.This also leads to a wall which isensure that the wall structurally sound and plumb is maintained.is plumb and this canresult in structuralweaknesses Refer Appendix 5 (case study 9)especially when thetechnique istranslated to largerbuildings.Penetration of water Thatched-earth tile rooffrom the roofs that • The roof frame must be built strong enough to support the weight. The best earth tiles arecaused water made with stabilized soilproblems from the • Also, wooden strips or metal rods (called stringers) must be placed in the roof at closeroof on inside enough intervals so that each tile rests on two stringers, either directly or indirectly.spaces. • 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. Refer Appendix 5 (case study 7)
Related drawings9. 10.11. 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 assembly11. Hunnarshala, Bhuj(wattle and daub) 8.12. 13. 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) 14. 35
PRIMARY CASE STUDIESProblem SolutionFlat slabs are not • CEB blocks were used to make vaults on top of CSEB walls and supported on concretepossible and so multi beams and a flat layer of kadappa stone was laid on top of the vaults leaving the sidestoreys cannot be space on top of the dome hollow.made. • 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.Formation of lintelsby earth blocks • 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. • Concrete, glass, steel, etc. have been sparingly used.
Related drawings 15. 16. 19.. 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 storeys with basement) 18. SEB as lintel on top of the door 18. 36
PRIMARY CASE STUDIESProblem SolutionFlat slabs are not Hourdi roofing used in auroville earth institute to create flat earth slabs.possible and so multistoreys cannot be • The hourdi block produced by the Auram press 3000 is used to create floors and roofs.made. • 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. Refer appendix 4(Cseb – hourdi roofing)
Related drawings20. 21.22. 23. 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
PRIMARY CASE STUDIESProblem SolutionAesthetics and pottery for insulation and aestheticsinsulation • 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 25. 24. 26. 28. 27. 24. Clay plates fixed on walls for insulation and the in- between spaces 29. 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 29. Tiled ceiling for vault, Auroville 38
Related drawings 31. 32. 33.30. 35. 34. 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 36. Inner view of the house 36. 39
PRIMARY CASE STUDIESProblem SolutionWood doesn‟t There is an alternative where pivoted windows are used where there is no need of woodenadhere with the frames and so the windows are directly attached by pivots to the two sides of the walls.earth walls andmostly create gapsbetween the walland the frame ofthe window.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 CSEB walls and the introduction of stabilized walls for rammed earth has given more easylarge and various ways of making large openings of various shapes and sizes.types of openings. Some of the examples as seen in kutch region are given in the drawing part.
PRIMARY CASE STUDIES37. 38. 40.39. 42. 41. 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) 43. 40
PRIMARY CASE STUDIESProblem SolutionFormation of organic shapes Cob is the technique that gives opportunity to form organic shapes.and single roofed buildings. 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 44 45. 46. 47. 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. 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. 49. 50. 41
PRIMARY CASE STUDIESProblem SolutionVaults and domes of earth Nubian vaultsmasonry requires skill With the Nubian vault technique, used for centuries in Upper Egypt, vaults can belabour . 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. The figures are shown in the next page.
Related drawings 52. 54. 55. 56. 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 53. technique. 42
BUILDING PROCESS - designingProblem SolutionTo choose earth Factors to be seen before choosing earth as a construction materialconstruction for the project. • 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.To design appropriate earth Factors to be kept in mind while designing earth building that can overcome thebuilding. surface and structural defects:Some of the problems arelisted below: • Wall thicknessSurface defects include • Spanning members(cracks; flakes; blistering; • Which technique to be used for construction peeling; loss of adhesion; • Number of storeysand boniness.) • Corner junctions • Joineries and detailing to avoid water and termite penetrationMaintenance & Repairs • Water is a major agent of decay for earth walls. Therefore, codes and other publications generally recommend not placing plumbing within earthen featuresStructural defects include water borne erosion of wall; freeze-thaw heave of wall; low level erosion at base ofwall; structural cracking(settlement, overload); bulging; abrasion damage; and rat runs and animal holes.- Pearson, 1992To convince the client for • By showing the possible options and benefits of earth construction and someearth good examples of already made earth buildings.Construction. • By showing the detailing that are done to overcome the issues related to waterFinalization of design with and insects, shrinkage cracks and stating the technique that is to be used.the client • 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.
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. 43
BUILDING PROCESS - designingProblem SolutionLess durable as a • It is mostly because of the less thought given to the construction details at theconstruction material initial stages of the design process.compared to conventional • The joint of the wall with the plinth has to be carefully designed so that thematerials. rainwater can flow down unhindered without entering the joint between wall and plinth.Water problemsTermite and rodentspenetrating the wallsRoof connections with thewall base 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.solution A is unacceptablebecause the extruded partof the plinth wont allowwater to flow and will becollected there causingswelling and peeling ofthe plaster and wall. • 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. Roof rafters should not rest directly on the earth wall, but instead on timber wall plates or beams as seen in A
BUILDING PROCESS – designingProblem SolutionLoam is not a standardised • Depending on the site where the loam is dug out, it will be composed of differingbuilding material amounts and types of clay, silt, sand and aggregates. • Its characteristics, therefore, may differ from site to site, and the preparation • of the correct mix for a specific application may also differ. • In order to judge its characteristics and alter these, when necessary, by applying additives, one needs to know the specific composition of the loam involved.Professionals make less • If the earth construction techniques and construction become widespread , all themoney from earth building prejudices and hesitations for its use as a construction material get removedprojects. gradually by proper training sessions and classes then it will lead to improvement in the construction industry in developing countries and indirectly to the professionals in money matters.• The traditional hut is • Now adays various techniques have developed which can produce good spanning limited to a single round members and structural members and so it becomes easy to cater various facilities or square room of about in a single roof with inner divisions of spaces by walls. 3m diameter with conical • Various shapes are possible other than those round huts with thatch roofs with the roof. innovation of loam walls and prefabricated panels of loam.• This limited size and shape means a single hut usually cannot accommodate several functions under one roof. Traditionally therefore, several huts are required to cater for the diverse requirements in a Single home.• With the traditional approach to building, all rooms (such as kitchen, sitting, bathrooms, bedrooms etc) cannot be contained under the same roof.• This results in functional inconveniences which is one cause of the social undesirability of traditional buildings.• Refer appendix, part 3 for drawings 45
BUILDING PROCESS – Construction(adobe)Problem SolutionLoad bearing floor slabs are • Loam elements which act as infill between floor joints also provide sound andnot possible. thermal insulation. • In Hungary in 1987, Gernot Minke developed load-bearing infill elements with cement-stabilised lightweight loam. various designs for load-bearing floor panels were developed at that time. • various designs for vaulted loam floors. Designs E, F, G, H are load bearing and use heavy elements made of earth. • A, B and C use earthen blocks, which transfer slab loads to the beams by vault- action under compression. • Design D shows a non-load bearing loam vault made by pouring lightweight loam over a curved reed mat. • When making loam-covered flat roofs, it should be kept in mind that roof edges are susceptible to mechanical damage, especially by wind and water erosion. This can be prevented by solutions of the type shown in • I,, j, k, l. If the surface of the roof is to be walked upon, then tiles are recommended as shown in l.
Related drawings A E F B C G D H 56. Mould for infill block and the created block I K L J 46
BUILDING PROCESS – Construction(adobe)Problem SolutionFixing fasteners to walls • Nails can be driven into an earth block walls more easily than into thoseleads to cracking of the constructed of baked bricks.blocks. • The more porous and humid the material, the easier one can drive a nail through it. Green bricks tend to split more easily than soil blocks and adobes. • If very thick nails are used, it is advisable to drill a hole into the block. • Heavy shelves or wall hung cabinets can be fixed to the wall easily using screws and dowels. Dowel holes, however, should be drilled large enough to • prevent blocks from cracking.With monolithic rammed • Different sections for larger wall panels made of lightweight mineral loam, areearth walls, or even with developed now adays.small-sized adobe masonry,manpower is high and • These can be used either in internal walls, or to increase the thermal insulation ofdrying time can delay exterior walls from the outside. Cavities reduce weight and increase thermalconstruction work due to the insulation, while simultaneously providing grip holds for easy handling.inherent water. • Similar elements that can be used for making vaults.
Related drawings 57. Interior wall of pre fabricated loam blocks 47
BUILDING PROCESS – Construction(adobe)Problem SolutionDue to mechanical impacts, As loam plaster is susceptible to mechanical impact, corners should preferably becorners often covered by wooden profiles, baked bricks or similar lippings.break during the handling ofmud bricks.The corners ofthe walls get spoiled anddeteriorated.Surface treatment for adobe • If sufficiently moistened with a tool like a felt trowel, exposed earth block masonrywalls with uneven surfaces or joints can be easily smoothened. Plastering is notProtection against rising advisable, since it interferes with the capacity of loam walls to balance internal airdamp humidity .• Exterior loam walls have • However, exposed earth block masonry can, if not aesthetically acceptable, be to be protected from rising given a wash of loam slurry stabilised with, for example, lime, lime casein etc. This damp in the same way as wash also impacts the wall‟s surface stability . baked brick or stone masonry walls.• A damp-proof course, a 3 to 4-cm-thick rich cement concrete layer is often used as an alternative.• This should be impregnated with bitumen or waste Mobil oil.
Related drawings Bricks Mud bricks Timber sections Earth wall 58. Wall plastered with lime, casein and loam 48
BUILDING PROCESS – Construction(adobe)Problem SolutionShrinkage is a problem • Prefabricated tiles made with stabilised earth can be used for flooring. Oneassociated with earth advantage is that since they are already dry, shrinkage only occurs in joints.materials when they dry. • Extruded green loam slabs consisting of a loam with high clay Content. They are extruded 3 to 10 cm thick, 50 cm wide and cut into lengths of up to 100 cm or more.Mud seems to be the natural • A one-inch thick layer of mortar (one part of cement to 3-parts of sand) can behome of termites so in areas laid all over the top of the basement wall before building the mud walls above it.where they are common the This is helpful in keeping out both termites and damp.same precautions have to be • Even better is to construct an apron of burnt brick or stone (or it can be rammedtaken as in all buildings to earth) all round the building (to prevent damage to the walls by splashing, of rainprevent their moving up into water) and this too can be plastered over with a rich cement mortar.the walls and eating wooden • Any thin sheet metal may be laid over the basement wall with a 3-inch downwardframes etc. projection before starting to build the superstructure mud wall above. This is expensive but very effective. • There are various chemicals on the market, which can be used.
BUILDING PROCESS – Construction(wattle and daub)Problem SolutionFrom a technical viewpoint, • The minimum width of the foundations will be 40cm.It is advisable to use a ratioit is clear the traditional 1.5 times the width of the wall. The minimum height of the base between groundwattle-and-daub has and the wall base will be 20cm.problems that reduce itsdurability to about 30 years.One of the main problems islack of a waterproof basesuch that the wooden polesand earth are in directcontact with the groundthereby getting exposed tomoisture and termite attack.the wall absorbs humiditywhen it rains and the daub iswashed off from the wattle.Flooding occurs if the level • In kitchens and bathrooms, the plinth should have a waterproof skirting of tiles,of the inside floor is lower slates, rich cement plaster etc.than outside. If the above • The skirting design should prevent water from leaking or broken pipes, whichoccurs the wall will be could flood floors, from reaching the loam wall.weakened and will easilycollapse in the event of anynatural disaster.