Among the many dramatic changes in world styles and ideas, the fashion scenario evidenced in the field of architecture is perhaps the most interesting. European thought and ideas dominated the scene till the early 20th century, when the designers in America and Japan came into their own. It is only in the last two decades that the simple and often unperceived movements of the ethnic building in the non-Western societies have been taken note of. But even this has been re-adapted to give a feeling of newness and to add to the many attributes of a fashion conscious urban society. We read occasionally about the; innovations of Hasan Faith, the experimental work in Central and South Americas, .the indigenous architecture of Africa and so on. The most noticeable element that emerges from this analysis is the adaptation of simple building techniques, and available materials in the creation of residential dwellings in rural and semi rural conditions wherein economy and availability play a major role in all decision making.
Perhaps, at this’ point, the emergence of a 'down to earth' analysis of the architectural process with the linkage of building technology to the social patterns and human responses would be of some value. Recently I had the pleasure of reading two very meriting books A Hut: Revolution and After by Sri Vinous Kale and A study in Sepia, both brought out by HUDCO and the Academy of Young Scientists. The two books give us an extremely refreshing view of the work based on the Gandhi an Principles. In trying to understand the simple and the profound within the ethos of a village, the authors have introduced an elegant and poetic element into the discussion which not only makes beautiful reading but also builds up the multiple realities in an unusual manner. It is a significant contribution and assisted me in another personal foray into the traditional practices of building with mud as it existed in Tamil Nadu.
Let me now elaborate on these ethnic building styles which have adopted mud, bamboo, palm wood, and coconut and palm leaves as the fundamental resources for residential building in the villages and semi-urban environments. The various types of building activity for which mud was employed exclusively or in combination with bricks, jelly and stone were as follows: as construction material for small village houses, as mortar with brick and stone, walk for forts and ramparts, mud plastering and mud flooring. Apart from this the centering for large structures was also made of mud alone or in conjunction with bricks. This was true of structures made of stone (temples) wherein the stone was laid without any mortar between joints and hence relied on stability only when the structure was completed. Upon completion the formwork that was erected with mud was taken down. This techniques made it possible to not only support the structure but also to create a large platform to work from. Even today this method is adopted for stone temples.
The quality of the clay is extremely important for all applications. To identify the right • mix requires a great deal of experience and this has been stressed a great deal in traditional building activity. Some of the best natural clay is found in Ramanathapuram district. Hence it is that we find lots of mud building in this locality. Manamadurai which is in the belt between Madurai and Ramanathapuram is well-known for the excellence of the clay and for the beautiful quality of pots made in this area.
The percentage of gypsum in the clay makes its plasticity ideal for working with. To this material some amount of sand is added to prevent cracking. High clay content soil to sand ratio can be 1:2 or 1:3, while low clay-content can be mixed with sand up to 1:1 V2 or 1:1. The sand should be river sand, and of coarse grains. Small pieces of stone or gravel (1/4") found in the sand can be added, for this gives greater strength to the mixture. If not found naturally such small stones or gravel may be added separately in small quantities.
When the soils have been mixed in the required proportions, water is added and the whole thoroughly mixed till a consistency suitable to roll the material into a large sized ball is formed. 'A great deal of pressure is applied to the earth by stamping with the feet, so that a fairly homogeneous mixture has been obtained. This mixture should be cured for 3 to 4 days. The mixing should be done in the open, under sunshine. This strengthens the clay and prevents cracking. Every day, water should be added in necessary quantity, to maintain the plasticity of the mixture. The curing and continuous mixing (by stamping) is to ensure complete homogeneity, and this increases durability of the material.
The cured clay should then be; mixed with fine straw, or rice husk to ensure better binding of the material. This method is very similar to the one adopted in making Variety or dung cakes meant for fuel. The quantity of hay or husk is approximate, and should be such that the plasticity of clay is not reduced.
To further strengthen the mixture decoctions, of certain seeds is added to the clay while-curing is carried out The Triphala (Emblic myrobolan, Beleric. myrpbolan and Chebalic myrobolan) are well proven to increase the binding of substances. Any one of these dry seeds may be used. The seed is firstly powdered and then soaked in water, by suspending the powder in a thin cloth bag. The water changes in color and absorbs the tanginess of the seed (the color change is compared to that of horse urine!). The soaking should be for about 2 days. A small quantity of this decoction is added to the clay mixture while curing.
The durability of earth-which has been treated with the decoction of the triphala can be understood clearly with the following description of one of the uses of clay in traditional practice. In some instances, earth mortar is also utilized to create divine Images in temple sanctuaries. In particular Vishnu and Muruga images are frequently composed of mortar of earth known as Kadusharkara. Though many other substances are adopted to make this process a highly sophisticated and skilled one, the appreciation of decoction of the triphala is a most important part Such a mortar of earth prepared in this manner, is capable of creating divine images that last through daily ablutions for well over two decades. In some instances, specialized preparation is supposed to keep the material intact for 75 years also! Thus we can say that the seed essence has remarkable durability.
Now that the mixture has been prepared, the place where the walls have to be erected is to be readied. There are some important rules to be kept in mind with regards to the preparation of the building site.
The actual space where the mud house is to be erected should be well cleaned and the wall trenches dug up to 1' or 1' 6" depth. The excavated earth should be removed. Similarly the earth within the house that is exceed should also be removed. Under no condition should this earth be used to refill the trench. A layer of river sand to a depth of 6" should be filled into the trench, and well consolidated. Over this the wall should be erected.
The building of walls:
The various walls comprising of the dwelling should be erected simultaneously. This includes outer walls and cross walls. Separately erected walls could develop cracks at joints. This should be avoided. The prepared earth can be either applied by hand without any formwork or placed within a bamboo or wooden shuttering. The latter method ensures better quality in the appearance as well as also in the compactness of the clay.
In one day not more than 1*6" in height of the wall should be built Alternate days should be left for drying. This is very important; otherwise the walls would not be strong enough to take the additional load. Each course 1'6" high is called Padai and even to this day the masons call the belts or courses laid as Padai. Window openings are laid out with bricks and with a light wooden lintel Similarly doorways are also set out with a hotel and door frames. The lintel should have a bearing of half the thickness of the wall on either side of the opening.
The wall should have a minimum thickness IT or 1*3" at its base. The top thickness can be half the thickness at base. The wall should be tapered as it is built The taper should only be on the outside so as to’ give a plane surface inside. When the walk are built by using a formwork then it is possible to change the thickness with sharp edges that can be ornamented and made aesthetically pleasant When built without the aid of formwork, it might be better to give a smooth curve on the outside so as to cover the irregularities of finish.
The total height of mud walls without support should not exceed T6". The top surface can be made slightly convex to aid cleaning. The thickness of the wall depends upon the height to which it should be built; the ratio of thickness to height can be 1:5 or 1:6. The maximum length of walls without either turnings or cross walls should not exceed 10’ to 12’. After the walls have been erected, they should be left exposed to the sun for one week before the roofing is done.
The roofing can be made with wooden poles over which either palm leaves or coconut leaves are tied. The poles can be of bamboo, casuarinas, palm wood (Panay), stone or country wood.' Of these Panay would be the most economical as well as durable. When suitably mature Panay is used, its age can be anything between 50 to 100 years. In Chet nod some houses boast a roof with Panay planks that have not been replaced for over 250 years. Hoe quality of the tree, the maturity of wood, its seasoning etc are extremely important to ensure this durability.
The mud walls of this house is not capable of taking loads of any kind, hence the roof should be independently supported. The framework of the roof can rest on wooden or stone posts placed either outside, inside or within the walls of the houses. The placing of vertical columns outside the house has been found to be most efficient. Placing them within the walls may lead to cracks, while placing them inside the bouse creates dead spaces in the rooms.
Next the flooring which has been filled with river sand to a depth of 6" to 12" is well consolidated and base jelly pored over. This consists of 3/4" of jelly in mud mortar 1:4. Over this the mud mortar which has been prepared for the walls is laid evenly for a thickness of 2" to 3". This mixture can be thinned a little and smoothened. Similarly the walls are also plastered by hand, over which a smooth stone is used to polish and finish the surface.
When the plaster has dried, cowdung is used to cover the walls and floor evenly. 3 or 4 layers of the dung mixture should be used before the wans are completed. Drying after each application is essential. Finally whitewash with, lime, and Kavi borders at base and top arc applied. Though the finished effect is aesthetic, the actual reason for the application of cowdung and Kavi most crucial. Along with the river sand bed, the cow dung, lime wash and Kavi help in safeguarding the building from the attack of termites. Building materials such as earth, wood and leaves are prone to termites, and this simple and extremely 'organic method has been used for preservation from insects in traditional building technology for centuries. To this day such buildings do not have termites and other insects.
Additional to this simple design, lofts may be added whenever necessary to increase storage spaces. Shelves can be introduced wherever necessary whilst the mud walls are being erected. Outer spaces can be further enhanced by excluding Timrod as also within the house. Platforms for storing grains or for placing the fire can also are introduced in the design. In the case of houses which are designed to have two floors, the intermediate floor may be supported with independent columns over which the next level of walls can be built following the same precautions as before. The total height would require the base walls to be made stronger and thicker. The thinnest portion of the wads should not be less than 9" (at the top).
In conclusion we would like to point out the simplicity and elegance of mud as a building material. It requires a great deal of personal involvement and supervision, as also high quality in the mixture as well as in the choice of wood for roofing but has the advantage of very simple methodology as far as construction is concerned. The coolness and the remarkable healthiness of the built environment are of utmost significance. The floors of such houses are extremely beneficial to sleep on and do not give rise to any physical problems (unlike Dunlop pillows and mattresses). Community housing with such building can be tastefully designed, as well as with unlimited variations. Unlike streamlining and cost reduction of high quality materials which requires the ascetic minimizing of form and beauty, this material lends itself to enormous imaginative use. Thus highly exciting as well as aesthetically beautiful buildings can be made.
Since the heights are restricted, the resulting effect would never be visually disturbing. The materials are also not processed through wasteful methods and hence are economically more viable. The whole community participates in this kind of building which lends itself to a healthier and more harmonious lifestyle. Perhaps the young of today could take a look at this building alternative, and not denounce it as a solution meant only for the economically weaker section.
The multiple solutions that I am able to perceive with the simple earthen, materials conjure up many visions in my eyes. The plasticity of earth and clay makes it possible for unlimited shapes and forms to be created, within the constraints of durability and rigidness. The structures can be diverse and yet retain their organic linkage with nature which is so sadly lacking in city-scopes of today. Community dwelling created with mud can even be finished with tiles instead of thatch so as to increase longevity - as can be seen in rural houses. Very interesting clusters are possible, with attention paid to the warmth and humanness of both built and open spaces. This would be enhanced by mixing gardens with dwellings wherein the lines of the one mingle with the natural contours of the other. Participatory building activity and personalized spaces could offer the necessary impetus for fostering belonging and accountability in community clusters and neighborhoods. Perhaps this alternative design process could be introduced as a part of school and college education, so that young people would like to experiment in living in interdependent clusters.