Slate Roof Cleaning in Cobham
Slate is the most delicate common roof material in Cobham. Pressure washing flakes the surface and accelerates delamination. Our slate-specific soft wash uses a milder biocide and longer dwell time to lift moss and lichen without ever touching the tile mechanically.
What's included
- Slate-safe biocide chemistry
- No mechanical contact with the slate surface
- Lichen removal experience on listed period properties
- Optional lead flashing inspection
Our process
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Step 1
Survey
We check for delamination, slipped slates and lead flashing condition.
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Step 2
Biocide soak
Diluted biocide is sprayed at low pressure — no scraping, no rubbing.
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Step 3
Extended dwell
Slate's smoother surface needs longer chemical contact time than tile.
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Step 4
Flashing report
Free written report on any flashing or pointing repairs needed.
Frequently asked questions
Is it safe to clean a slate roof?
Yes — using soft wash only. Pressure washing slate causes delamination and can void any remaining manufacturer warranty.
Will cleaning remove lichen from slate?
The biocide kills lichen at the root. Dead lichen flakes off over 2–3 months of weathering — we never scrape lichen from slate as it removes surface material.