The Soil

Every publication on the making of mud brick building spends considerable time and space discussing the qualities of earth best suited to the purpose of making mud bricks. When the mud brick 'novitiate' starts studying these pros and cons be may be forgiven for becoming a little nervous and disheartened, especially if in his first 'infant' steps the bricks crack or otherwise misbehave in the drying. But be really should not. He should remember that he is embarking on a great journey of discovery and adventure and not on a quick fire instant certainty. Practically any earth can be made suitable for bricks in the long run but initial trial and error is both experimental and experiental and will enable, problems to be overcome with a little patience and discernment.

The two primary ingredients of mudbricks are clays and sands. It is clearly impossible to make stable bricks out of pure sand and almost as difficult to make them out of pure clay. The former has no clay or colloidal material to give binding to the unstable granular base and the latter requires granular admixture to control the colloidal materials that will crack and break up with uneven shrinking and are inordinately sticky and heavy to form and to handle. Almost any soil that is from one-third granular and two-thirds colloidal to one-third colloidal and two-thirds granular materials will make adequate mud bricks that will produce walls of the necessary strength and character. Mud is after all only humble dust of ground wetted down and it can never have the qualities of marble, stone or baked bricks. The operative word to use is its regard is sufficiency rather than efficiency. Beginners in the creative activity of building in mud tend to fall between these two schools. One group can never believe that they won't melt in the rain or otherwise collapse and the other group are equally convinced they're stronger than either stone or concrete. The truth lies between these extremes. The most important quality required is a rare commodity called common sense.

The Anakie bricks were made away by Graham Bird on his property four miles away. It had some nearby soil added to produce a balanced result. This granular material was granitic topsoil, an ideal base to fuse with the powdery colloidal material. There were some breakages in carting and laying but none from rain damage. Robyn, assisted by her young brother, Sturt, achieved a timeless quality in their work. They fully demonstrated the special factor available to the mud brick layer as to no other building tradesman, that is the hand-made and individual process it permits. Every man can be his own architect. The problem is that, this happy chance seldom occurs because the once-off builder lacks experience and information and needs to compensate for this by reading the 'How to do it' books which generally fail to tell the where, the what and the why of the problem. It was fascinating to observe how Robyn's experience eventually infected Sturt who was on his first mud brick Job. By the time the brick rendering was nearing completion, he was taking control to allow Robyn to get on with laying the floors. He was discovering that what he first thought was just a method of earning some money concealed satisfying creative overtones.

Today it is quite normal to purchase ready made bricks so that people with busy lives who can employ their time more efficiently by paying for them in order to get on with the erection of an earth building without delay. Every earth builder must balance out these alternative. for himself. If he chooses to make the bricks himself, he should always keep to the forefront of his mind the nature of the material so that be can produce the best result with the least effort. This means essentially that he must be confident in his understanding of its plasticity and manipulable character.

In the making of bricks the true secret lies in the completeness with which every particle of earth is surrounded with water. Water is the catalyst that unites sands and clays into solid blocks of mud that will dry into satisfactory bricks. It cannot be over-emphasised that the major failure in mud brick strength is uneven mixing, wetting down, and the incomplete penetration of water through the particles of soil. If this has to be done entirely by hand it is tedious, hard work. In such circumstances the best method, especially in heavy, clay loam, is to till a wide shallow hole with water then place the mud brick soil on top. It is much harder to wet down the dry earth by placing the water on top of soil. The finer the soil mix the


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