A massive earthquake had razed Shillong to the ground in 1897. This led to the creation of the 'Assam-type' construction that comprises bamboo frames, ikra weed and mud plaster for walls, roofs of thatch or corrugated galvanised iron sheets. The 1950 earthquake in Assam was the real test of this technology.The quake measured 8.5 on the Richter, changed the course of the Brahmaputra river, submerged the old city of Dibrugarh, but the buildings were unscathed.
The foundation in the Assam-type construction comprises wood posts driven into the ground to a depth of 65-90 cm. Columns run from the foundation to the top storey.The superstructure rests on these columns for secure bearing.
The walls, composed of wood posts, are spaced at 1.5-2 metres apart. A 15-centimetre diameter wood post beam supports the roof. A framework of bamboo with ikra reed panels is anchored to the frame from the walls. Ikra is normally plastered with mud or, sometimes, a lime mixture. The voids are infilled with plastered ikra reed or split bamboo panels, which keep the structure light.