Slate Roof Cleaning in Hampshire

Natural slate

Natural slate is dense and sheds water well, so moss usually grows in the joints and along the bottom edges rather than across the face. Slates are thin and crack easily under foot. Soft washing from the ground with water-fed poles kills moss, algae and lichen at the root without anyone walking the roof. See a period slate roof case study.

Fibre-cement (artificial) slate

Many homes from the 1970s onwards have fibre-cement slates. These are more porous than natural slate and grow algae and moss faster. Fibre-cement slates made before 2000 may contain asbestos, as its use was banned in the UK in 1999. Those slates should never be jet washed, scraped hard or broken. A low-pressure biocide wash is the appropriate method, and the specialist should confirm the slate type before quoting.

What a proper clean includes

1. Gentle removal of moss from joints and edges, without walking on the slates.
2. Low-pressure biocide treatment of the whole roof.
3. Gutter clearance afterwards (gutter cleaning).
4. Photos of any slipped or cracked slates. Cleaning often reveals slates that have already slipped, which a roofer can refix.

Areas

South Hampshire and the Solent, including Southampton, Eastleigh, Winchester, Romsey, Fareham, Portsmouth and Havant. See all areas.

Common Questions

Can a slate roof be pressure washed?

It is not recommended. Slates are thin and crack easily, and pressure washing older fibre-cement slates can release fibres. A low-pressure soft wash with a biocide is the safer method.

My artificial slates are from the 1980s. Is that a problem?

Fibre-cement slates made before 2000 may contain asbestos. They can still be cleaned with a low-pressure biocide wash, but should not be jet washed, scraped hard or broken. Mention the age of the roof when you ask for a quote.

Will cleaning show up slipped slates?

Sometimes. Moss can hide slates that have already slipped or cracked. The specialist should photograph any they find so you can have a roofer refix them.

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