Page 37 - JCAU-7-2

Journal of Chinese
Architecture and Urbanism Moisture damage in plastered heritage building

2.2.2. Assessment of degradation levels in heritage
buildings
Following in-depth field research, a comprehensive and
detailed assessment of degradation levels in heritage
buildings within Anchang historical town was carried
out. The research team employed various assessment
methods, such as visual inspections, surveys, moisture
measurements, and infrared testing, to quantitatively
classify the extent of building deterioration. Four classes
of deterioration were identified: extremely serious, very
serious, generally serious, and slightly serious.
Using the riverside façade of the BCW building as a
Figure 6. He Gongsheng’s residence on Temple Bridge. Source: Photo by case study, notable differences in degradation levels were
Si Chen (2024) observed across different parts of the building (Figure 7).
The stone masonry at the base of the wall exhibited the
structure. Studies indicate that weathering-related most severe deterioration, characterized by peeling and
erosion is the predominant deterioration pattern moss growth. These pathologies pose significant threats
observed in Anchang’s heritage buildings (Ioannidis to the building’s durability and structural stability. In
et al., 2022; Rek-Lipczynska, 2019). This phenomenon contrast, the relief floral decoration on the frieze above
not only affects the visual appearance of the buildings the entrance displayed generally serious pathological
but also exposes the structural layers, leading to features, such as salt efflorescence and mold (Junier et al.,
further damage. 2017). The deterioration observed below the eaves was
• Crust formation: Damage from humidity manifests relatively mild, involving slight dampness affecting the
as hollowing, cracking, salt crusting, dehiscence, and wall surfaces.
spalling, with salt crusts being the most prominent.
Soluble salts and other substances within the building 2.2.3. Moisture detection on wall surfaces
materials precipitate when water evaporates, forming The study included a detailed analysis of wall moisture
crusts on the building surface. This process results in a levels in the BCW building. To ensure the accuracy and
whitening effect (Rodgers et al., 2017). In severe cases, comprehensiveness of the data, the wall was meticulously
the surface layers of building materials disintegrate measured in sections along horizontal and vertical axes
and detach, exacerbating structural damage. (Liang et al., 2023). Moisture data from the walls of the
• Biological colonization: This form of deterioration is historic buildings were collected using a specialized
primarily caused by mosses and molds, which grow moisture detector (Figure 8). The horizontal direction was
on the plastered exterior finishes of masonry building divided into eight segments, labeled A through L, while
walls and mortar joints. The dampness of building the vertical direction was subdivided into 18 segments,
materials creates an ideal environment for biological numbered 1 through 18. Variations in humidity were
growth, which subsequently covers the masonry noted at the horizontal junctions of different materials,
surface and accelerates corrosion (Kuka et al., 2022; Li particularly at points B and C (Figure 9), due to differences
et al., 2020). in the thickness of the footing material. Stable humidity data
b) Morphological characterization of deterioration at the intersections of the vertical and horizontal segments
were recorded. In addition, overall wall temperatures
Different building materials respond to environmental
conditions with different deterioration patterns, reflecting were recorded using an infrared thermometer, serving as
distinct underlying mechanisms. Therefore, it is essential a reference for data analysis. To minimize variability and
to analyze these patterns in relation to the materials used enhance reliability, the recorded data were averaged over
multiple measurements.
in similar environment settings (Fadeev & Nasybullina,
2020). The research team conducted a comparative analysis Based on the wall humidity measurements (Table 3),
of the river-facing façade of the BCW and HGS buildings the study revealed a correlation between the height of the
in the Anchang historical town. Since the interiors of these wall and its temperature and humidity. In general, walls
buildings had been renovated and repaired, the analysis closer to the ground exhibited lower temperatures and
focused exclusively on their exterior structures, which higher humidity, while those farther from the ground
exhibited more pronounced signs of deterioration. had higher temperatures and lower humidity (Dang et al.,

Volume 7 Issue 2 (2025) 7 https://doi.org/10.36922/jcau.4606