LAHORE, Nov 23: Dampness is damaging almost all historical monuments in the country while the authorities concerned continue to overlook it.
Dampness is one of the prime reasons for the deterioration of the core structure of the buildings and is also destroying the embellishments, especially their plastered surfaces.
Though the old buildings used to be built without damp proofing course (DPC), the authorities concerned did not take any measure to save them for future generation. Monuments in the city like Wazir Khan Mosque, Badshahi Mosque, the tombs of Dai Anga, Khan Bahadar and Budhu da Awa and mausoleum of Sadiq Nihang in Shorkot are the prime victims.
The moisture in buildings if left unattended can result in the damage to plasters, decorations and structures and partial or total collapse. Punjab Archaeology Department director Shahbaz Khan, who is also an archaeologist, told Dawn on Tuesday that dampness occurred in the old buildings due to humidity, condensation, rain, sub-soil water and capillary action. Besides, he said bricks or other porous masonry units used in foundations take and transmit moisture upwards because of capillary action, damaging surface coatings.
Usually no DPC was provided in the buildings constructed prior to the end of 19th century. Therefore, he said the ground-borne moisture easily reached from bottom to top. Dampness also caused growth of algae, fungi, lichens and bacteria that often discoloured monuments.
Giving details of measures to address the problem, Mr Khan said ground-borne water could be intercepted by providing a seal in and across the masonry. Strengthening of loose plasters and repair of cracks were also necessary, he added.
"The walls of old buildings are so thick that laying of reinforced cement concrete DPC is not possible. However, this can only be achieved either through physically cutting in the DPC in the masonry or by injecting chemicals. Chemicals can be applied both vertically and horizontally which will prevent water seepage from any direction," concluded Mr Khan.
