4.1.2 Materials
a. Foundations:
Foundations are being proposed only on soils other than rock. The foundations consist of stone masonry laid in stabilized mud mortar (5-10% lime or cement)
b. Improved wall construction
The walls can be built with salvaged stones from the debris or new stone
The masonry should be laid in improved mud mortar. Since mud disintegrates during rains, thus making the walls vulnerable, it is proposed to stabilize the mud mortar with 5-10% cement or lime. Lime has been used extensively in historic and traditional buildings and, in contrast to cement, can be used in all weathers.
Walls will be braced with wooden logs or battens to be placed both inside and outside at cill, lintel and roof levels. This will ensure that the wall instead of collapsing as a whole can come down in stages with lesser casualties.
In case there are any walls that have partially survived, they can be integrated into the construction of the house by retrofitting them with wooden battens or logs.
c. Roof
G.i. sheets have been used extensively in the area for roofing. Some may be salvageable from the debris. They are light and can be transported easily. It is proposed to use 24 gauge sheet fixed to wooden battens and rafters. The roofs will be formed in an incline in order to shed rain and snow easily. Detailing for fixing etc. is to be provided in the working drawings being developed.
Other options for roof covering include kana matting and asbestos cement sheets.
The sheet should be covered by heavy gauge polythene for water tightness. Since the thin sheets will not provide comfortable condition within the house during the cold weather, mud filling and mud mortar with lime and bhoosa (straw) is proposed to provide the necessary insulation.
The wooden members being proposed for both bracing and roofing can be Eucalyptus or Peepal logs. Any kind of inexpensive wood battens can also be utilized. All wooden members should be treated against termite and weathering.
d. Flooring
A lot of concrete debris from collapsed roofs is available on many of the sites. This concrete debris can be broken into pieces which should be laid on rammed earth and compacted into place as sub base. The final layer of flooring is proposed to be lime terracing using lime, sand and coarse aggregate. This is a low cost solution and has been used extensively in historic buildings.
e. Doors and windows
Since it will be difficult to fabricate doors and windows on the site, it is proposed to standardize their sizes. A 7’0”x3’0” wooden paneled door and 3’6”x3’0” wooden window is proposed. Since glass is likely to break, the window panes can be Plexiglas or else they could carry wooden paneling. The windows can be transported in packs.
f. Plinth Protection
A plinth protection consisting of concrete or other rubble covered with lime terracing is proposed to protect the walls from surface water. |
