The area of any building that creates the first impression, irrespective if it’s a small or large corporate building or even if it’s historical buildings remain its exterior. A clean exterior represents a more hospitable and attractive front.
However, like all building elements, facades can be subject to soiling and structural deterioration, often accelerated by exposure to man-made pollutants.
To ensure that facades remain aesthetically pleasing, effective in terms of functionality and structurally sound, a well-planned maintenance and cleaning regime will need to be developed.
Not all building facades require the same care and attention. Different types of facade finishers require different cleaning methodologies, chemicals and technologies.
- Terra cotta
- Decorative metal
Factors that determine the cleaning frequencies of the exterior of a building are:
- Metropolitan cities
- Rural and country areas
- Traffic density
- Environmental conditions
- hazardous urban air pollution
- Acid rain
- Weather and atmospheric conditions
- Function and purpose of the building
What generally needs to be cleaned and removed from façades;
- Dirt, dust and grime
- Bird droppings
- Smoke, smog and soot
- Industrial pollution
- Atmospheric gasses e.g. sulphur dioxide and nitrogen oxides
- Creeper plants
Prior to any façade cleaning project an experimental clean must be done in an inconspicuous area, before any full cleaning gets underway. It’s also imperative to deploy safe, secure systems and follow safety rules. Façade cleaning often requires working at heights, as most business premises are more than two storeys high. A risk assessment must be done, to ensure all safety aspects comply with relevant legislations, code of practices based on local municipal regulations. The principal contractor and the client are normally held jointly and severally liable for any mishaps or violations of the law.
Equipment and technology that generally used today to do façade cleaning but not limited to are:
- Motorised platforms and cradles
- Robotic façade cleaning machines
- Water Fed poles
- Rope platforms
- Brushes nets belts
Robotic technology is definitely the future of façade cleaning with many companies currently working on new innovations.
METHODS OF FACADE CLEANING
- Handwashing – this application is usually done on small buildings, with soap or a detergent and cold water.
- Water soaking with nozzles, a slow steady stream of water and neutral chemical is used to loosen dirt and wash it away with brushes. The duration of soaking is important to determine as well as the proper Per Square Inch (P.S.I.).
- Steam cleaning - this method is especially used for smooth hard surfaces such as masonry marble and granite.
- High pressure steaming – start with a low to medium pressure between 100-400 pounds per square inch (PSI), using, if necessary, a chemical as well.
- Sand blasting (not favoured by many municipalities) dry sand blasting which involves forcing sand from a tank through a hose and nozzle by compressed air at various pressures.
- High pressure water – this method involves water jetted at a high pressure. It’s inexpensive and less intrusive to the interior of a building.
- Chemical cleaning: - this method requires the application of specific chemicals substances onto the surface to soften or dissolve soiling and stains or bleaching it until it’s the same colour.
- Water Fed poles – this has become the method and equipment of choice as technology evolved, it is very apparent in window cleaning, it is safer and more efficient. The rotating poles are lighter and easy to use. Pure water is used in this type of cleaning and leaves the glass and surfaces free from streaks.
- Pure water is processed water which eliminates all minerals and impurities, known as total dissolved solids (TDS) and is measured in parts per million (PPM), O is considered pure.
- The two purification methods are: de ionisation – where the water is filtered through. On exchange resin which attracts and removes all impurities minerals reserve osmosis – where water is passed through a series of membranes and filters which retains and flushes out impurities and minerals.
Each method has its own advantages and disadvantages. Contractors must use extreme caution and discretion when selecting the technology, methodology and chemicals to be used on the building.
About the author:
Clive Damonze is the Director at CleanFM Consultants. He is the Co-author / compiler of the book “The African Business Guide for the Cleaning Industry”.(Launched in Amsterdam, May 2012 and initiator of the first ever meeting of 25 Cleaning Associations around the world (Amsterdam May 2012).