Render and wall cleaning in Teesside
Render cleaning in Teesside costs £5 to £10/m² using soft washing: a low-pressure biocide treatment that kills the algae causing red, green and black staining. High pressure strips and scars modern render, so soft washing is the only safe method on k-render, monocouche and painted finishes.
Red walls and green walls
Drive through Wynyard, Ingleby Barwick or any of Teesside's newer estates and you will see it: render that was cream when the house was built now streaked with red-pink staining, or gone green on the shaded elevations. Both are algae. The red streaks are Trentepohlia, an airborne alga whose pigment protects it from sunlight, and the green film is common green algae on walls that stay damp. Black crusty spots are lichen. All three feed on exactly what Teesside gives them: moisture, mild temperatures and, near the coast at Redcar and Seaton Carew, salt-laden air that keeps surfaces damp longer.
Why render must be soft washed
Modern renders, k-render, monocouche, silicone and acrylic finishes, have a thin coloured surface layer. High-pressure washing strips that layer, leaving permanent pale patchwork scarring that cannot be cleaned back and often can only be fixed by re-rendering. The same goes for painted masonry and older pebbledash, where pressure blows the stones off the wall. Soft washing is the only correct method on render: a biocide solution applied at garden-hose pressure, left to kill the growth, then gently rinsed. The staining fades as the algae dies, over days for green growth and a few weeks for heavy red staining.
Prices on Teesside
Render cleaning runs £5 to £10/m² of wall area, so cleaning the front elevation of a typical semi quotes between £150 and £400, and a full detached house £400 to £900. Height and access are the main drivers: gable ends and three-storey work may need a scaffold tower, and heavy red staining can need a second biocide application. Because the biocide keeps working after application, a soft-washed wall typically stays clean for several years, far longer than the same wall blasted with water alone.
Which walls suffer worst
North and east-facing elevations, always, and anywhere a leaking gutter or overflowing hopper keeps a stripe of wall wet. Trees and shrubs against the wall make it worse by shading and dripping. If a section of your render stains far faster than the rest, the cause is usually water: get the guttering sorted at the same time as the clean, or the staining returns within a year. Contractors quoting render work will usually spot and flag the gutter fault as part of the survey.