CLAY or MUD STRUCTURES Part - 2

THREE: JOINTS OF MUD, DAUBING AND PLASTERS

Wattle and Daub construction

In locations where building stones or wood and grass products (bamboo, Cain, long straws) are available, Mud has been used as joint filler, daubing, layering or plastering material. In Himalayan range stone boulders have been used for creating walls. These were internally and superficially packed with mud or plastered. (Though the boulder walls, in spite of packing and joint filling remain unstable in earthquakes -are now banned.) In stone masonry the joint filling or external packing (lining) with mud, stops cold winds, rain-water penetration and insects proliferation.

Mud packed stone wall

Clay daubing is mud plaster over woven mats of bamboo, grasses etc. fixed over frames. Similarly wood, metal and other lattices are used to hold a layer of mud. This method creates, comparatively a thinner, and so a lighter wall structure. The framing structure provides the load-bearing capacity and lateral stability. Often inner partitions of Mud wall houses are made by this method. 

WATTLE and DAUB is a technique of creating both, in-situ walls and pre-cast panels that are attached to the framing of the building. It has been used since neolithic period. A woven lattice of wooden strips called wattle is daubed on both sides, with plastic slurry of mud. As the mass is very thin, it dries out fast with very little cracking. The surface is re-daubed on both sides to refill the residual cracks and achieve a smooth finish. 

Daubing left out to form opening

The mud requirements are small, so select quality mud is used. It is often rotted with dung, vegetation waste to increase the fibre content. Other binders mixed with the mud include lime, jaggery, gums, polymers, etc. For the second coat, materials like chalk, talc, iron oxides are used to add whiteness or colour.

Wattle is traditionally made by weaving thin branches or thin slats between upright stakes. The wattle made as loose panel forms in-fill plates. Nowadays to avoid white ants attacks, stainless steel, aluminium and polyester extruded longs and lattices are used in place of wood-based wattles. 

Clay daubing thin wall

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