Yes — that's the whole point. Soft washing uses a biocidal solution that kills mould, algae and lichen at root level. Pressure washing just removes the surface layer and leaves the roots behind. Here's how it works.
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The most important question to ask before booking any exterior cleaning service is whether the method actually kills the growth or just removes what's visible on the surface. This distinction is what separates soft washing from pressure washing, and why soft wash results last 2 to 4 times longer. Soft washing uses a professional grade biocidal solution — a chemical product specifically formulated to kill biological growth at the cellular level. The solution penetrates the mould, algae or lichen, kills the organism including its root system and spores, and then the dead matter is rinsed away at low pressure. Pressure washing simply blasts the visible layer of growth off the surface, leaves the root system intact, and the growth re-establishes from those surviving roots within months.
The primary active ingredient in professional soft wash solutions is sodium hypochlorite — the same compound used in water treatment and medical sterilisation, at appropriate dilutions for building surfaces. Combined with surfactants that help the solution penetrate biological growth, and applied at the correct concentration for each surface type and growth type, it kills mould, algae and lichen at the cellular level. The spores are also killed, which is critical — surviving spores are what cause rapid regrowth after pressure washing.
Biological growth on roofs and walls doesn't just sit on the surface — it roots into the substrate. Algae produces root-like filaments that anchor it to porous surfaces. Lichen has rhizines that physically penetrate tile surfaces. Moss has root-like structures that grip into surface irregularities. Soft wash solution penetrates these root structures and kills the organism throughout — not just on the visible surface. This is why the growth doesn't bounce back within weeks.
Yes — eventually. Once the biocidal solution has degraded and the inhibiting effect wears off, new airborne spores can land on your roof and begin a new colony. This is why results last 12 to 24 months rather than permanently. The key difference from pressure washing is that the new growth has to start from scratch — there's no surviving root system to accelerate regrowth.
Professional grade soft wash solutions are safe for building materials when applied by a trained operator at the correct concentration and with appropriate rinsing. Gardens, pets and painted surfaces are safe after thorough rinsing. We take care around all garden beds, water features and sensitive plantings during every job.
Soft washing kills mould, algae and lichen at root level including spores — the results last 12 to 24 months. It's not permanent in the sense that new airborne spores will eventually land and begin a new colony, but it eliminates the existing growth completely rather than just clearing the surface.
Because pressure washing doesn't kill the growth — it displaces the visible layer while leaving the root system intact. The surviving roots regenerate the colony rapidly, typically within 3 to 6 months.
Soft wash solutions contain sodium hypochlorite, which is the active ingredient in bleach. However, professional soft wash products are specifically formulated for building surfaces at appropriate concentrations with added surfactants — they're not the same as household bleach applied directly.
Yes, after thorough rinsing. We take care to cover and protect garden beds during application and rinse thoroughly after treatment. Gardens and pets are safe once the surface has been thoroughly rinsed.
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