Case 1
- Introduction
- Causes of Defects
- Good Practices
- Standards
- Maintenance and Diagnostics
- Remedial
- Similar Cases
- References
Maintenance and Diagnostics
Maintenance
For decisions on surface repairs, consider the ease of access for future work, relative cost of hiring and
erecting scaffolding, and the probable frequency of maintenance in accordance with BS 8221-2, SS 509-2
or equivalent. Record and retain documentation of all executed works on façades, including photographs and non-destructive survey techniques, to provide background information prior to further assessment
or work. Carry out semi-annual inspections of stone-wall elements and inspect all elevations. Keep accurate and cumulative records of inspection findings in accordance with ASTM C1496, BS 8298-1 or equivalent. Regular cleaning is critical for the long-term durability and appearance of natural stone façades. Perform periodic joint repairs (i.e., sealant replacement, tuck pointing, and cleaning) in
accordance with ASTM C1496, BS 8298-1 or equivalent. Perform repairs and restoration works in
accordance with ASTM C1722-18, BS 8221-2 or equivalent. For cases of cracked or broken stones, carry out the following: a) Seek assistance for stone replacement; b) Tuck point or caulk crack with sealant if fragments are stable and secure; c) Monitor closely for additional cracking or movement.
Diagnostics of Defect (see also NDT)
Thermography can be used to identify the position of cracks. A range of crack widths, representing mechanical damage, has been induced under controlled laboratory conditions. The method is based on the characteristics of heat flow phenomenon, in a conductive medium of specific geometry, which is intended to model predetermined boundary conditions.
