Salt attack and rising damp on house buildings at the tsunami-affected areas

Abstract

Post tsunami 26 December 2004, rising damp and salt attack are two underestimated phenomena emerging on building construction on the tsunami-affected areas in Banda Aceh city, Aceh Province of Indonesia. The severity of building quality deterioration, particularly on the typical masonry walls, has never been observed by local inhabitants to have been escalated before the tsunami event. Such phenomena persistently present even after approaching the second decade of the post-tsunami event. The present study is the first attempt to explore the evidence of rising damp and salt attacks of the houses around the Banda Aceh city. Forty-five houses were purposively sampled based on their visual appearances being affected by the salt attack and rising damp, the heights of the rising damp, and also groundwater salinity in the vicinity of the sampled houses. The results show that the rising damp heights on the walls are relatively high in any location within the tsunami inundation boundary 500 m from the shoreline. However, a turning point where rising damp height reduced remarkably to less than 1 meter was identified as the distance of houses increased beyond 500 m from the shoreline. Overall, the high level of water salinity brought by tsunami inundation during the early post-tsunami has been an important controlling factor contributing to the salt attack and rising damp, regardless of the houses’ distance to the shoreline, but may have been indirectly influenced those phenomena in the long run.