The surface comes first
Different materials react differently to pressure and cleaning products.
Concrete, block paving, natural stone, render, timber, UPVC and roof tiles all have different characteristics.
A method that works perfectly well on a driveway may be completely unsuitable for a rendered wall or roof.
The contamination matters too
Dirt isn't always just dirt.
A surface might have:
- Algae
- Moss
- Lichen
- General grime
- Atmospheric pollution
- Oil or grease
- Organic debris
- Old coatings or staining
Identifying what you're actually trying to remove helps determine the most suitable approach.
Pressure isn't always the answer
Sometimes mechanical pressure is the right tool.
Sometimes a cleaning solution can do much of the work.
And sometimes the best approach is a combination of treatment, controlled pressure and thorough rinsing.
The aim should be to achieve the required result without putting unnecessary stress on the surface.
Technique makes a difference
Even with the right equipment, technique matters.
Nozzle selection, pressure, distance, angle and speed can all affect the finished result.
So can preparation.
Plants, windows, doors, electrical equipment and surrounding surfaces may all need to be protected before cleaning begins.
Experience is about knowing when not to use pressure
One of the most important parts of exterior cleaning is recognising when a particular approach isn't appropriate.
A good result isn't necessarily the result that looks most dramatic while the cleaning is taking place.
It's the result where the surface is clean while remaining in good condition afterwards.