Soft-wash cleaning for roofs and rendered walls
Roof and Render Cleaning
Roof and render cleaning removes moss, algae, lichen and black staining from roof tiles and rendered walls using a soft-wash method — low-pressure application of a biocidal treatment rather than direct high-pressure water — which cleans effectively without dislodging tiles or damaging render, priced per square metre.
Definition
What Roof & Render Cleaning covers
Roof tiles and rendered walls, especially north-facing or shaded elevations, are prone to moss, algae and black fungal staining over time. Because roof tiles can be dislodged and render can be damaged by direct high-pressure water, this is treated as a soft-wash job: a biocidal solution is applied at low pressure to kill growth, which is then left to weather off or is gently rinsed away, rather than blasted with a pressure washer.
Suitable for
- Roofs with visible moss, algae or black staining, particularly on shaded or north-facing slopes
- Rendered walls affected by algae or general discolouration
- Properties wanting to slow moss regrowth in gutters caused by roof moss
Not suitable for
- Roofs with damaged, slipped or cracked tiles, where cleaning should follow any necessary repair, not precede it — we flag this if seen before starting
- Render with existing cracks or defects, where the cause should be addressed by a render repair before cleaning, since cleaning alone won't fix an underlying defect
Process
How the work is carried out
- 01
Roof and render survey
Checking the condition of tiles or render and confirming there's no repair needed first.
- 02
Protection
Protecting guttering, downpipes and surrounding planting before treatment.
- 03
Soft-wash application
Applying a biocidal treatment at low pressure to kill moss, algae and staining.
- 04
Aftercare
Advising on the weathering-off period and any follow-up rinse where needed.
Typical timescale
The soft-wash application itself is usually completed within a day for an average roof or elevation; visible improvement often continues over the following weeks as growth weathers off.
Cost guidance
Roof and render cleaning typically costs £5–£15 per m² in our area, or is priced as a fixed job for a defined roof or elevation, with access, roof pitch and the extent of growth affecting where you fall in that range. We confirm pricing after a site visit or photos rather than a blind flat rate.
Limitations and exclusions
- Tile or render repairs identified during survey are quoted separately and, where structural, should usually be resolved before cleaning
- Results depend partly on weathering after treatment; heavy growth may benefit from a follow-up treatment, discussed at survey stage
Areas we cover
Roof & Render Cleaning across Sussex, Surrey, Kent and South London
Local property styles, planning authorities and neighbourhood coverage for roof & render cleaning in each town we work in.
Related services
You may also need
FAQs
Roof & Render Cleaning FAQs
Why is roof cleaning done as a soft wash rather than pressure washing?
Direct high-pressure water can dislodge or crack roof tiles and damage render, so roof and render cleaning uses a low-pressure biocidal treatment instead — it kills moss and algae at the root without the physical risk of blasting the surface.
How quickly will I see results after treatment?
Some improvement is visible soon after treatment, but moss and algae typically continue to weather off and fade over the following weeks as the biocide takes full effect, rather than disappearing instantly.
Will you check my roof for damage before cleaning?
Yes, we survey the roof or render first and flag any slipped tiles, cracks or defects — cleaning over a damaged roof isn't advisable, so repairs are addressed first where needed.
Discuss your roof & render cleaning project
Tell us about the property and what you have in mind, and we'll arrange a site visit.
Last reviewed 2026-07-28.