Case 1
- Introduction
- Causes of Defects
- Good Practices
- Standards
- Maintenance and Diagnostics
- Remedial
- Similar Cases
- References
Maintenance and Diagnostics
Regarding using stone as the external façade, the recommended sealers will be one that gives the repellency against weathering and ultraviolet rays. Once sealed, the stone will be more protected and with proper cleaning, it will retain the sealer for a longer duration and keep your stone protected without damaging the stone’s natural beauty.
Regular cleaning should be performed to cleanse the granite stone of any spores of algae or fungi.
Do not use acid-based cleaners (below pH 7), high alkaline (above pH 9) cleaners or strong degreasers for maintenance. Acidic cleaning agents should not be used for granite as it attacks the pyrite (iron sulphide) inherent in granite, resulting in a brown stain.
It is also recommended to reapply sealers to stones every 2-5 years to ensure continued performance of granite cladding.
Adopt ASTM C1193-16 or equivalent to identify areas with remedial sealant repair or maintenance work, as multi-storey structures require a periodic façade inspection at an interval of about 5 years. Replace failed sealants immediately in accordance with ASTM C1401-14, BS EN 13022-1 or equivalent. Test suspected failure of waterproofing using ASTM C1521-19, BS EN 15651-1 or equivalent. Use ASTM C1487-19 or equivalent for remedial work for glazing sealant.
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.
Elastic recovery meter
Sealant deterioration can be determined by the use of Elastic Recovery Meter (INERT).