Soft washing is increasingly popular as the preferred method for cleaning roofs, driveways and exterior surfaces in the UK. Unlike pressure washing, it uses low pressure and specialist biocide solutions to safely and thoroughly clean surfaces without risk of damage. Here's what it costs and what to expect.
How much does soft washing cost in the UK?
Roof soft washing in the UK typically costs between £300 and £1,500 depending on roof size and condition.
Typical prices:
Soft washing is generally 10–25% more expensive than standard pressure washing, but the results last significantly longer — typically 3–5 years rather than 1–2 years.
What is soft washing?
Soft washing is a cleaning method that uses low-pressure water (no more than 500 PSI, compared to 1,500–3,000+ for a pressure washer) combined with specialist cleaning solutions including biocides, surfactants and algaecides.
The chemicals do the hard work — killing moss, algae, lichen and bacteria at the root — while the low pressure safely rinses them away without risk of cracking or displacing tiles.
It's widely considered the gold standard for roof cleaning, particularly for clay tiles, natural slate, and older or more delicate roofing materials.
Soft washing vs pressure washing
Pressure washing is cheaper and faster, but the high pressure can: - Dislodge or crack fragile tiles - Force water under tile overlaps, risking leaks - Remove protective coatings from some tile types - Only treat the surface rather than killing spores at the root
Soft washing is gentler, kills growth at the root, and keeps surfaces cleaner for longer. For most UK roofs — particularly those with clay, slate or concrete tiles — soft washing is the recommended option.
Pressure washing is more suitable for hard, robust surfaces like concrete or block paving driveways.
What surfaces can be soft washed?
Soft washing is suitable for: - All roof tile types (clay, concrete, natural slate) - Rendered or painted walls - Fascia and soffit boards - Conservatory roofs - Garden walls and fencing - Driveways and patios (with lower concentration solutions)
For driveways, most specialists use a combination of soft washing and light pressure washing depending on the surface material.
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Frequently asked questions
How long do soft washing results last?
Typically 3–5 years, depending on your environment. North-facing roofs, properties near trees, or those in damp climates may see regrowth sooner. A good quality biocide treatment extends results significantly.
Is soft washing safe for all roof types?
Yes. Soft washing is the safest cleaning method for all roof types, including natural slate, clay, concrete and flat roofing materials. Always confirm that your contractor has experience with your specific tile type.
Does soft washing cause any mess?
The cleaning solutions and loosened debris need to be managed carefully. A good contractor will protect your garden and gutters during the process, and clear any residue from gutters, paths and borders after the clean.
Is soft washing the same as roof sealing?
No. Soft washing cleans the surface. Roof sealing applies a protective waterproof coating after cleaning to help repel water and prevent future growth. Many homeowners choose to do both at the same time.