Architecture without architectsVERNACULAR ARCHITECTURE LOCAL MATERIALS Stones Adobe or sun-dried bricks Mud Bamboo reeds. Local grass or leaves Timber This plinth is built of laterite stone or brick masonry from a depth of 1′-0” to the ground level after excavating the loose earth and ramming the earth below in many layers of sand. . gravel and pebbles.PLINTH The plinth depth is 1/3rd the width of the block . masonry walls with adobe or sun dried bricks and stone blocks. and wattle and daub walls made by plastering mud over thin panels of woven bamboo or reed fixed to a palisade(wooden fence or wall). fine mud mixed with cow dung was applied neatly by the sweeping of the palm of the hand. to ensure cohesiveness. . cob walls. 3. lime. molasses etc. Mud was mixed with coarse sand. 2.MATERIAL USED FOR CONSTRUCTION OF WALL There were mainly 3 types of mud walls used commonly in Kerala: 1. Originally for floor and wall finishes. paddy husk or grated hay as reinforcement and mixed with vegetable juices. and should give a ringing sound when tapped. Dried bricks were stacked with gap in between filled with paddy husk. Brick should not break if dropped to the ground. .SUN DRIED BRICKS • • • • • The soil was soaked with water and fruit juices. The bricks were then soaked in water to a period of 6 months to one year before using. It took 10to 11 days for the whole thing to burn to form adobe brick. The outer gaps were sealed using clay after the pile grew to a comfortable size to fire. and seasoned before it was cast in wooden molds and dried. and water. . straw. The mass of a cob wall helps to stabilize indoor air temperatures. Mortar or plastering: No mortar joints in a cob wall which adds to the building's strength and integrity.COB WALL: • • • • • • System Of construction: A cob mix consists of soil with sufficient clay. or small stones. Physical properties: Cob walls are strong enough to bear the load of one or two storey. rough sand. The minimum thickness of a cob wall should be 16 inches. Cob and straw can be combined in the design of the exterior walls of a structure to take advantage of thermal mass and insulation. Physical properties: Lightweight. . It is highly suitable for seismic zones. and has good insulation characteristics because of its layered construction.WATTLE AND DAUB WALL: • • • • System Of construction: It consists of a load-bearing structure. between which is woven a lattice netting from vegetable matter and then plastered on either side with earth that is mixed with straw or other vegetable fibre to prevent shrinking on drying. It can go very well up to three storey. which is usually wooden. WATTLE AND DAUB WALL . 5 to 2m intervals along the length of the walls where required.TIMBER FRAMED / PANELED WALL • • • • The timber houses in Kerala especially in the southern region were composed of walls built of frames and panels called nira . . The beams at plinth level were supported on granite pillars about 50cm x 50cm x 150cm embedded in the ground. These granite supports were provided at all wall junctions and at 1. These buildings were constructed almost entirely of timber from plinth level upwards. Above the wooden plinth beam were wooden pillars at all wall junctions and at intervals along the walls . • Between these pillars were wooden planks joined to each other by tongue and groove joints. .• Plinth level with bricks or laterite. accurate joinery.CEILING Timber is the prime structural material abundantly available in many varieties in Kerala .from bamboo to teak. artful assembly and delicate carving of wood work for columns. walls and roofs frames are the unique characteristics of Kerala architecture. Perhaps the skilful choice of timber. . . in filling the timber floors and making bricks and tiles after pugging and tempering with admixtures.for walling. Palm leaves were used effectively for thatching the roofs and for making partition walls.CLAY AND PALM LEAVES Clay was used in many forms . *pairs of rafters (kazhukol) would be bound by horizontal rods going through other pairs of rafters. ridge and wall plate become one unit of roof construction. BENT ROOF SHINGLE ROOF . hip. It seems that the rafter-rod construction was originally a simple rope-tied construction which is usually utilized in humble bamboo huts. *pairs of rafters will meet on a ridge (montayam) to make the hipped roof. the rod.ROOF CONSTRUCTION Roofs in Kerala houses reflect the outstanding features of shingle and bent roof construction. The basic structural elements consist of * pairs of rafters (kazhukol) resting on an wall plate (uttaram). Thus. rafters. This rod is called vala. It reflects the logic of tropical sloping as seen in the shingle. saddle roof and the span of eaves of the roof slopes. CONSTRUCTION OF PITCHED ROOF . both ends resting on a wall plate (uttaram). Both rafters (Kazhukol) are usually stiffened by a longitudinal beam and longitudinal stiffener called valabandam that clamp both rafters. If the hall is wide. For a narrow hall. the roof construction needs only a pair of rafters (Kazhukol) tied on top by a one ridge beam. . thus the original linear longitudinal beam was elaborated into an arch-like truss. called Viskhamba.Another interesting feature is a trapezoidal construction work that looks like the main arch structure in the wooden truss system of Gothic architecture. the pair of rafters needs a stronger longitudinal beam. rice straw etc. Some thatch materials which are commonly used:-long straw . however.grass or reed. The stalks of thatching grass are normally hollow and about 3 mm thick. 16 . are solid and about 3-4 mm thick. palm straw . MATERIALS USED FOR ROOF COVERING Thatching makes use of materials that are naturally available . Dekriet stalks. wheat straw. CONSTRUCTION OF THATCH ROOF Thatching with coconut leaves or rice straw: A frame (using half split bamboos cut out of bamboo of approx. The thickness of the thatch in this case varies from 7.5 cm to 10 cm .) is prepared using split bamboos at 15 cm spacing both ways and tied with strong fibres like jute string . 17 . A layer of coconut 3 to 5 cm thick or of rice straw 10 to 15 cm thick is laid over the frame and tied with it. Thatching with palm leaves/reeds: A frame similar to the one described above is made but the spacing of the split bamboos is kept 30 cm centre to centre . 5 cm dia. THATCHING MATERIALS THICKNESS OF THATCH(T) HALF SPLIT BAMBOO FRAME SPACING(S) Coconut leaves 3-5 cms 15 cm c/c Rice straw 10-15 cms 15 cm c/c Palm leaves 7.5 cms 30 cm c/c Reeds 7.5 cms 30 cm c/c 18 . • Tie with strong fibre like jute at 30 cm c/c. 19 .THATCH MAKING WITH IMPROVED THATCH PANEL CUT BAMBOO FOR BAMBOO SPLITS OR TAKE STRONG REEDS • Make bundles of 12 mm dia.I wire • For reeds-tie with strong fibre like jute string. • For bamboo splits-tie with G. MAKE GRID MATS • Length of mat = room width + projection • Width usually 90 cm . Tie panels with supporting purlins using G.Spread thatching material on bottom mat place top mat over thatching materials tie top and bottom mats Start placing from lower side overlaps not less than 10 cm Supporting purlins to be at the centre of overlaps.I wires . 21 . 22 . It can be built with local material by local labours. Thatch has good wind resistance. It is easily available.ADVANTAGE Thatching materials range from plains grasses to waterproof leaves found in equatorial regions. thatch does not absorb large amounts of water. It is a good acoustic insulating material. If it is properly maintained. 23 . It is thermal insulator. It is not much safe against disaster. Rodents can cause extensive damage when present in the house. Thatch can be maintenance intensive.Birds looking for food. In warm. It can easily destroy by wind pressure and catches fire quickly. Animals can cause damage. 24 . Thatch Roofing is purely temporary structure.DISADVANTAGE Thatch is susceptible to decay and decomposition and precautions must be taken to minimize the possibility of this process taking place. gathering nestmaking materials or nesting in the roof . wet climates thatch is prone to fungal attacks. The principle for making the most durable mats is to make sure that the leaf blades are squeezed tightly and neatly together as they are stitched onto the batten.PALM THATCH There are two ways of preparing feather type leaves to make thatch mats : FIRST METHOD The leaf blades are stripped from the stem and then stitched to a thin wood batten. This batten may be made from the palm leaf rib. or perhaps from split bamboo. 25 . The standard mat of 600mm length should be made of about 200 leaf blades. Fan-shaped leaves generally need no preparation other than drying and flattening.SECOND METHOD The second method is to split the stem in two so the leaf blades hang from one side. Palm thatch mat .the complete mat is 600mm long x 500mm wide Woven coconut palm t 26 hatch mat . The two pieces are laid back to back and the leaf blades woven together to form a mat. nailed or wedged into place on a roof with the leaf blades facing downwards. They are tied. Hip and gable edges and the ridges of palm thatched roofs are particularly vulnerable to wind and rain damage. Woven coconut palm mats are generally laid double thick. and therefore the durability of the roof depends on the size of the overlap.ROOFING WORK Mats are tied to the rafters in overlapping layers starting at the eave. usually within two years. When the upper layer decays. The thickness of the coat. . layer by layer. to achieve acceptable durability. the roof is rethatched. There should be a maximum of 100mm between the mats. if sufficient material is available this gap should be reduced to 60mm. Inside view of coconut palm Inside view of fan-shaped palm thatch thatch Layering of woven palm thatch. . 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