View of the installation "Coexistence" | Damp Proof Course and Salt Control

Rising damp and salt efflorescence are the most common causes of degradation seen in heritage buildings around the world. Macau Historic Centre is located in a coastal city with abundant ground water and relatively saline soil due to continuous land reclamation. Heritage buildings located along the original seashore suffered “rising damp” and “salt attack”, in which dissolved sea salt migrates to the wall structures via capillary action of the ground water. This phenomenon can eventually lead to the permanent destruction of the heritage fabric. In order to protect the existing heritage structures and prevent future damages, liquid damp proof course is injected into the foundation of each wall by a gravity-drip injection system, specifically designed for the high density grey bricks used in the heritage structures in Macau. As a result, crystallised salt is removed by dusting and vacuuming. Salt scavenging plasters and vapour permeable paint are employed to ensure free “breathing” is activated through all walls.