Case 1
- Introduction
- Causes of Defects
- Good Practices
- Standards
- Maintenance and Diagnostics
- Remedial
- Similar Cases
- References
Introduction
Type of Building: Public Building
This case presents crazing of the plaster surface on an external wall. Crazing is characterized by irregular and hexagonal fine cracks typically between 6 and 75mm across over a contiguous area, like the surface of a cracked egg shell. It is also referred to as map or web cracking. It is usually the result of excessive drying of the plaster. This weakens the plaster and cause crazing. Poor surface curing and too wet mix bleed water when toweling, may be possible causes for excessive drying of the plaster surface after construction.
Crazing may be present but not noticeable until the cracks are filled with dirt. This is a type of shrinkage crack that is very common worldwide.
Cement-rich steel-trowelled smooth finishes are particularly most liable to craze, on the other hand, mixes with a scraped or textured, or other rough finish are highly resistant to this defect.
Crazing of plaster if not treated may result in peeling and delamination which may appear in the following forms:
