How can pressure washing cause damage?
The most obvious problem is excessive pressure. However, there are several other factors involved.
Damage can occur through:
- Using too much pressure
- Holding the nozzle too close
- Using the wrong nozzle
- Cleaning at an unsuitable angle
- Spending too long on one area
- Using high pressure on a surface that isn't suitable for it
For example, aggressive cleaning can disturb pointing between paving or brickwork. Softer materials can also be etched or marked.
What about render and painted surfaces?
These surfaces need particular care.
Paint can be stripped or damaged by excessive pressure, while some types of render can be marked or have their surface compromised.
This is one reason why lower-pressure cleaning methods and appropriate treatments are often preferable for delicate surfaces.
Does a powerful pressure washer mean better results?
Not necessarily.
A professional cleaner should be thinking about the surface and contamination before deciding how much pressure to use.
The machine may be capable of producing very high pressure, but that doesn't mean that pressure should be used directly on every surface.
What else matters?
The nozzle makes a significant difference. So does the distance between the nozzle and the surface, the angle of cleaning and the speed at which the operator moves.
The condition of the surface matters too. Older or already-damaged materials may require a much more cautious approach.
When is professional cleaning worthwhile?
If you aren't familiar with pressure washing equipment, it's easy to underestimate how much force is being applied.
Professional cleaning isn't simply about owning a pressure washer. It involves understanding what the surface can tolerate and knowing when an alternative method would be more appropriate.