Typical 2026 prices
Mid-terrace (front elevation only): £200–£350. Semi-detached (full house): £350–£550. Detached (full house): £500–£900. Large detached or three-storey: £800–£1,400.
K-Rend and silicone render are charged at the same rate as standard render. The cleaning method (soft-wash) is identical.
Painted masonry and pebbledash sit at the lower end. Brick is usually 20–30% cheaper than render because no biocide pre-soak is needed.
Why your render keeps going green or pink
Modern silicone-based renders attract algae fast — the silicone binder is a food source, and the textured surface holds moisture. North-facing walls and shaded elevations are always the worst.
Pink staining is usually a different algae (Trentepohlia) that thrives on damp, sheltered walls — common on west-facing K-Rend in rainy parts of the UK.
Power-washing makes both worse in the long run — it strips the surface and creates more anchor points for spores. Soft-wash plus biocide is the only manufacturer-approved method for K-Rend.
How long the result lasts
A proper soft-wash plus biocide treatment keeps render visibly clean for 3–5 years on most UK homes. North-facing walls and tree-shaded elevations come back first.
An annual or biennial biocide top-up (£100–£200) extends that to 6–8 years between full cleans.