Call Now 01494 355645 | Mon – Fri: 9:00 – 5:00
View of a slate roof being cleaned using a cherry picker for access and steam cleaning to remove moss, algae and biofilm

Slate Roof Cleaning – Methods & The Risks To Avoid.

Facebook

So you have a slate roof and you are researching the best way to clean a slate roof?

We’ve cleaned a many slate roofs over the years and here we share our insights…

Cleaning of slate tiles rooftops is perhaps not as much in demand as it is for concrete roof tiles, or indeed clay tiles.

This is because the smooth surface of slate tiles makes it difficult for moss to adhere to and grow from – generally only growing in the joints between tiles where vegetation and bird droppings can get caught and grow moss.

View of a slate roof being cleaned using a cherry picker for access and steam cleaning to remove moss, algae and biofilm

Types Of Roof Slates

Natural Slate Roof With Full Gutters
These are natural slates, further down the page you will see man made slates
Many people do not realise that there are many variations of slate roof tiles, ranging from pure natural slate tiles through to completely man made look alikes that are in fact manufactured with plastic, fiberglass, recycled slate, slate dust, cement and asphalt.

On some older properties you will even find slate tiles that contain asbestos.

The first step to cleaning a slate roof is to identify the type of slate used, is it natural or man made? If it is man made then we need to identify if the slate tile is manufactured with fibreglass, cement board, asphalt or off course asbestos.

The first step to cleaning a slate roof is to identify the type of slate used, is it natural or man made? If it is man made then we need to identify if the slate tile is manufactured with fibreglass, cement board, asphalt or off course asbestos.


If the slate tiles are uniformed then there is a very high chance that they are man made as slate is obviously a natural product and natural product are not uniformed by nature!

The Hidden Risk Of Cleaning Roof Slates…

Perhaps the biggest risk, particularly for an inexperienced roof cleaner is the fact that the coating of man made slate tiles perishes over time, when this has happened and a roof is cleaned the biofilm and atmospheric dirt is removed – exposing the failed coating, this make the slate tiles appear to be a whitish, fibrous colour.

Basically the coating has perished exposing the inner fibers of the man made slate tiles.

Some companies suggest doing a test patch in an inconspicuous area to see if the coating has failed, while this may sound like a great idea and the perfect solution it can lead to huge disappointment once your roof has been cleaned.
Roof Constructed With Roofing Slates With Failed Coating
If you look closely at the slates above you can see white patches where the coating has failed on these man made slates.

You guessed it, the tiles in the test area were sound and once the whole roof has been cleaned and chemically treated there are whiteish, slates with failed coatings visible across the roof.

Here at The Roof Moss Cleaners Ltd we always advise against the treatment of man made slate roofs as until each tile has been cleaned it is literally impossible to know the outcome.

If a client is happy with the risk then of course we will proceed with a complete roof scrape and biocide treatment, or steam clean followed by biocide treatment – as per your request as our client.

Methods Of Physically Cleaning Slate Roof Tiles & Natural Roof Slates

Steam Cleaning A Slate Roof From A Cherry Picker

Natural roofing slates can be brittle and crack fairly easily unless a high level of caution is exercised by the roofers working on your roof.

Some brands of man made slates can be much stronger and happily take the weight of a man on a roof ladder however we prefer to take the safest option possible in terms of safety of your roof and that of our roof cleaning team.

We always take the safe approach to roof cleaning, carrying our slate roof cleaning with a MEWP (Mobile Elevated Work Platform) in the form of either a Mobile Boom Lift cherry picker, a Truck Mounted Cherry Picker or a Mobile Access Tower.


The cleaning itself is carried out using either:


Telescopic roof scraping tools


Or


Telescopic steam cleaning technology

Slate Roof Cleaning Before & After Photos

This Man Made Slate Roof Was Heavily Infested With Moss Before Scraping
A Roof Scrape Only Because The Coating Has Failed On The Slates - A Vast Improvement None The Less
This client opted for a slate roof steam clean - giving an instant result
The steam cleaning was followed by the application of Biocide which will repel future moss growth.
Dirty Slate Roof Prior To Steam Cleaning
View of a slate roof being cleaned using a cherry picker for access and steam cleaning to remove moss, algae and biofilm

Contact The Roof Moss Cleaners Ltd Today For An Expert Roofing Slate Cleaning Service

Call our office on 01494 355645 between 9am and 5pm Monday to Friday, or submit your enquiry via the form on this page.

We always aim to give a fixed price roof cleaning quote as fast as possible, on the same day in many cases!

If you are considering having your roof cleaned then do not hesitate to contact Peter at The Roof Moss Cleaners Ltd on 01494 355645