The Science Behind a Spotless Roof.
Gomoss combines low-pressure soft washing, biocide chemistry and commercial-grade equipment to remove moss, algae and lichen without ever damaging your tiles. Here's exactly how we do it — and why the method matters.
Soft washing, not pressure blasting.
High-pressure jet washing looks dramatic but it strips the protective granular coating from concrete and clay tiles, cracks mortar and forces water under the felt. It's the number one cause of premature roof failure after a "clean".
Our soft-wash system runs at under 60 psi — roughly the pressure of a garden tap — and lets professional biocides do the work. We kill the organism at the root, so the roof stays cleaner for far longer.
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No tile damagePreserves granular coating, mortar and pointing.
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Kills at the rootBiocide destroys spores pressure washing leaves behind.
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Longer-lasting resultsRegrowth-free for up to 12 months versus weeks.
A repeatable, surveyed method.
Survey & Assessment
Drone or ladder inspection to grade contamination, tile type and access. You get photos and a fixed quote before any work begins.
Manual Moss Removal
Thick moss is carefully scraped and brushed by hand from the top down — no gouging, no pressure — and cleared from gutters and valleys.
Biocide Soft Wash
A DEFRA-compliant biocide is applied at low pressure across the whole roof, killing algae, lichen and spores at the root.
Protect & Report
Optional protective treatment slows regrowth. We leave the site clean and send a full before/after report.
The right technique for every surface.
Different surfaces and contaminants need different chemistry and pressure. Explore the exact methods our technicians deploy.
Roof Soft Washing
The core of what we do. A calibrated biocide is fan-sprayed across concrete, clay or slate tiles at under 60 psi. Rather than blasting the surface, the treatment kills moss, algae and lichen biologically and the roof continues to self-clean with each rainfall over the following weeks.
- Sodium hypochlorite / DDAC-based biocide, correctly diluted per tile type
- Even fan-tip application for full coverage without runoff pooling
- Downpipes and landscaping masked and rinsed to protect plant life
Commercial-grade kit, calibrated for care.
We invest in professional equipment so we can control pressure, chemistry and reach with precision — the detail that separates a lasting clean from a quick blast.
Soft-Wash Pump System
Diaphragm pump with adjustable flow, delivering biocide at a consistent low pressure for even, controlled coverage.
- Operating pressure< 60 psi
- ApplicationFan-tip nozzle
- ReachUp to 12m
Rotary Surface Cleaner
Enclosed spinning-bar cleaner for patios and driveways that removes streaking and delivers an even, professional finish.
- Working width400–500mm
- FinishStreak-free
- Water recoveryOptional
Gutter Vacuum & Poles
High-reach vacuum with carbon-fibre poles and a wireless inspection camera to clear and verify gutters from the ground.
- ReachUp to 3 storeys
- CameraWireless HD
- AccessGround level
DEFRA-Compliant Biocides
Professional-grade, correctly diluted treatments that kill moss, algae and lichen at the root — safe when applied by trained technicians.
- ActiveDDAC / hypochlorite
- Kill rateUp to 99%
- ComplianceDEFRA / HSE
Drone Roof Survey
Aerial imaging to safely grade contamination and spot cracked tiles or slipped slates before we ever set foot on the roof.
- Imaging4K aerial
- OutputPhoto report
- SafetyNo-access survey
Height & Safety Kit
Full working-at-height equipment — harnesses, roof ladders and edge protection — so every job is carried out safely and insured.
- AccessRoof ladders
- Fall arrestHarness system
- InsuredPublic liability
See the difference for yourself.
| Factor | Gomoss Soft Wash | Traditional Pressure Wash |
|---|---|---|
| Tile & coating damage | None — under 60 psi | Strips protective granules |
| Kills spores at the root | Yes — biocide treatment | No — spreads spores |
| Typical time before regrowth | Up to 12 months | Weeks to a few months |
| Risk of water ingress | Minimal | High under felt |
| Mortar & pointing | Preserved | Can be blasted out |
| Before & after report | Included | Rarely provided |
Done properly. Done safely.
Working at height and handling biocides demands proper training and insurance. Every Gomoss job is planned around a risk assessment, carried out with correct PPE, and fully covered — so the only thing you notice is a spotless roof.
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Fully insuredComprehensive public liability cover on every job.
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Trained techniciansWorking-at-height and safe biocide handling certified.
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Property protectionPlants, downpipes and landscaping masked and rinsed.
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Local & accountableAylesbury-based team you can meet and trust.
The detail, answered.
Will the biocide harm my plants or pets?
Why doesn't my roof look instantly clean after treatment?
Is soft washing safe on older or fragile tiles?
How long until moss and algae come back?
Do you need to get on my roof to quote?
Ready to see the Gomoss method on your roof?
Get a free, no-obligation quote from a local expert. We'll survey your roof, explain exactly what it needs, and give you a fixed price — no pressure, and no pressure washing.