HYDERABAD: Air gaps between layers of lime mortar at Charminar, and insects eating into the binding material are two of several reasons for damage in Hyderabad’s iconic monument, found the Archaeological Survey of India (ASI) during an inspection on Tuesday.
The condition of the lime plaster on the chajjas on the projected balcony of the southwest minaret is so bad that at the parts where the lime mortar is damaged, the material crumbles with mere touch. A closer look into the same portion shows that there is a fine gap between the core of the structure and the thick lime plaster.
There are several reasons for this, the chief among which is that the southwest minaret faces the brunt of the southwest monsoon. Heavy rains lash on it every year, and the wind, which is stronger as one goes higher, also causes damage. Man-made factors such as vibrations from nearby illegal constructions and work by municipal authorities also compound to the damage, said an ASI official.
The ASI official said, “Rainwater contains a diluted form of nitric acid. When it enters through the crack, it damages the lime mortar.” The damaged lime mortar gains density and becomes too heavy for the structure.
Not just the southwest minaret of the Charminar, but various parts of the monument also need attention. Take, for instance, the sibara coating -- the topmost protective layer of the lime plaster which has peeled off at various places. Superintending Archaeologist of ASI MK Chauley said that sibara coating prevents rain water from seeping in.
However, there is another small yet significant reason causing damage to the monument. An examination of a globular portion that was once a part of a decorative part of the monument showed that insects had caused damaged to it.
An ASI official said that back in the 19th century, masons used terracotta pipe, then bound it with jute and put it together with lime plaster to form the globular shape. A closer look into the damaged portion shows that insects have eaten into the jute.
So how is the ASI going to restore it? Chauley said that lime plaster has to be replaced wherever it has been damaged. “We don’t interfere with the monument unless there is a need for it. We follow archaeological principles like that of John Marshal which underline that there should be minimal intervention,” added Chauley.