Case 7
- Introduction
- Causes of Defects
- Good Practices
- Standards
- Maintenance and Diagnostics
- Remedial
- Similar Cases
- References
Maintenance and Diagnostics
Annual inspection and maintenance in accordance with BS 5427: Part 1, Table 9.
Regular cleaning work, of twice a year for normal environments and 4 times a year for polluted or marine environment is needed to keep the building clean. Proper cleaning agents and equipment should also be used. The mildest method possible (non-alkaline detergent) should be used, particularly for aluminium which has been anodised. The cleaning specifications should be followed closely with respect to the frequency and method of cleaning.
Coatings may require re-decoration after 10-15 years.
Maintenance
Consider availability of adequate water supply, drainage provisions and electrical power supply to choose a façade cleaning method. Records of cleaning operations (including photographs before and after cleaning, and drawings of nature of deposits, thickness and patterns) should be kept for buildings of significance in accordance with BS 8221-1, SS 509-1 or equivalent. Maintain the façade in a state as near as possible to its new condition. Ease of façade maintenance can be expressed by the frequency of necessary maintenance operations, labour and supplies necessary for each maintenance operation, and number of possible ways of removing stains, graffiti, etc., or ISO 7361 or equivalent.
Detect/determine staining of porous substrates by joint sealants (ISO/NP 16938-1). Adopt the recommendations for treatments for controlling organic growth in accordance with BS 8221-2, SS509-2 or equivalent. Repair painted surfaces damaged by wear and tear; wash down; remove defective paint film; apply sealer/primer (if necessary); and repaint in accordance with BS 6150, SS 542 or equivalent. TiO2 only works where there is sunlight. Conventional cleanings are still needed for non-coated areas. For areas coated with TiO2, conduct neutral cleaning annually.
Periodic cleaning is necessary to maintain the aesthetics of tiled façades. A neutral cleaning agent should be adequate if a periodic maintenance schedule is performed.
Diagnostics of Defects (see also NDT)
- The range and degree of the staining can be assessed by visual inspection.
- If further certification is required, the glossiness of the surface can be measured to determine the area where staining is most serious. This could be done by using a Gloss Meter.
See also Staining of Facades