We hear this question constantly: "Can't I just blast everything with a pressure washer?" The short answer is no — and using the wrong method on the wrong surface causes expensive, sometimes irreversible, damage. Here's how the pros decide what to use and when.
Pressure Washing (2,000–4,000 PSI)
Uses pure water force. It's ideal for hard, dense surfaces that can take the impact:
- Concrete driveways and sidewalks
- Brick and natural stone patios
- Unsealed hardscape surfaces
Soft Washing (Under 500 PSI + Biodegradable Solution)
The right choice for anything that can be damaged by force — which is most of your home's exterior:
- Vinyl and wood siding — high pressure forces water behind panels and causes mould inside the wall cavity
- Painted surfaces — pressure strips paint and can void manufacturer warranties
- Stained decks — pressure raises the wood grain and forces re-sanding before any new finish can be applied
- Windows — pressure can crack seals, causing condensation between panes
- Roofing — pressure washing shingles removes the protective granule coating
Why Soft Wash Results Last Longer
Soft wash solutions kill mould and algae at the root rather than just blasting the surface off the siding. When you pressure wash mould, you remove the visible growth but leave behind the spores — which regrow within weeks. Our biodegradable soft wash solutions eliminate the organism completely, so results last 4–6× longer. It's the professional standard for anything above ground level.
Quick Reference: Which Method for Which Surface?
- Concrete driveway → Pressure wash
- Vinyl or wood siding → Soft wash only
- Brick patio → Pressure wash
- Deck (stained) → Soft wash only
- Windows → Soft wash / manual
- Interlock pavers → Low-pressure wash + resanding
Not sure which service your London home needs? That's exactly what our free on-site assessment is for. We'll look at every surface and recommend the right approach before any work starts. You can also read about our soft wash siding service and interlock cleaning for more details.