Case 1
- Introduction
- Causes of Defects
- Good Practices
- Standards
- Maintenance and Diagnostics
- Remedial
- Similar Cases
- References
Introduction
Inherent Properties
Type of Building: Commercial Building
Rust stains are common in all stones used in building façades. The visibility of the stains depends very much on the colour tone of the stone itself. A lighter coloured stone such as Kashmir White will show significantly more stains than Black Galaxy, which rarely shows visible stains.
Selection should hence include checking for inherent minerals which are especially prone to staining, such as Pyrite, Illite, Smectite and Styolites. These are also expansive minerals which are able to absorb moisture, and hence, will retain the rust colour within the stone.
In this case, a hook was found to rust. As rain flushes over the rusted hook, rust was deposited onto the granite panels below. This formed the brown stains as shown.
