Case 2
- Introduction
- Causes of Defects
- Good Practices
- Standards
- Maintenance and Diagnostics
- Remedial
- Similar Cases
- References
Introduction
Type of Building: Public
Mould has spread widely over the paint coating of concrete beam and the slab soffit. Mould may grow on damp/moist biodegradable finishing materials. The moisture content of the indoor environment and its retention are the primary environmental factors to determine the extent of growth of fungus. The most important moisture parameter for the growth of microbial organisms is the water activity (or relative humidity, RH) of the substrate instead of moisture content of the material.
The main moisture source appears to be the water seeping in from the exposed brick external wall of the toilet unit. Water seepage through these mortar joints were evident since efflorescence has formed along the joints. Mortar joints on external walls are most vulnerable to rain water penetration as external wall is subjected to the inclement weather which may lead to thermal and structural movement of the wall. Therefore, pressure from the rain may drive the water into the mortar joints, and through capillary action seeps into the internal face of the external wall.