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Bio-wash Roof Cleaner
Stop the moss, Save the roof!
Bio-Wash Roof Cleaner is a deeply penetrating, aqueous biocidal solution, formulated specifically to target the problem of damaging moss and mould growth on a variety of external mineral surfaces, including manufactured roof tiles, slates and profile sheeting.
Supplied as a concentrated liquid, one 5 litre container diluted makes 25 litres of ready-to-use cleaner, which will treat up to 125 sq.m. It is easy to use and can be applied as a stand-alone treatment or as a companion pre-treatment, ahead of surface repair & coating.
Bio-Wash Roof Cleaner is a synergistic “broad spectrum biocide” which means it simultaneously targets and kills moss, plus a whole range of other organisms that grow on roofs, including: green mould, black mould, lichens and algae. It is generally used in concert with other cleaning methods, including pressure washing and mechanical removal (scraping/scrubbing).
• Neutralising and removal of heavy moss from concrete roof tiles
• Cleaning & restoring clay roof tiles
• Surface sanitising after pressure washing roofs
• Cleaning slate roofs for moss removal, especially north facing elevations
• Asbestos cement (AC) roof maintenance
• Restores the colour of organically stained roofing materials
• Improves adhesion quality of water-proof coatings
• Prevents moss re-growth under new coatings
How does it work?
Moss is a particularly insidious roof invader because it very much plays “the long game” and the damage it inflicts can go un-noticed until quite far into the deterioration cycle. A few clumps of moss appearing on a roof might seem innocuous enough, but this little plant has an appetite and your roof is now its food source!
Once established it can spread remarkably quickly, especially with the second essential ingredient; moisture. Moss loves our rainy climate and will thrive in damp, shaded conditions which is why, if you look carefully, you will notice that the north elevation of most roofs exhibit more organic growth than south facing surfaces.
The root system of the moss gradually loosens the surface and the organism retains moisture up to 16 times its dry weight. Additionally, this semi-permanent moisture encourages the emergence of corrosive salts (which might otherwise have remained locked away for years) from concrete tiles, clay tiles, mortar joints and even asbestos cement sheets. The release of these corrosive chlorides contributes further to the porosity of the roof material and weakens it.
Freeze/thaw erosion exacerbates deterioration of the roof surface. In winter the moisture laden moss freezes along with the moisture it has trapped. This has the effect of micro-rupturing the surface of the roof, as the freezing water expands to form ice, which in turn permits deeper water penetration, worsening frost cracks and eventually rendering some roofs completely porous.
Frustratingly, cleaning the moss by pressure washing or scraping alone can actually make matters worse. This apparent paradox arises because:
a) Removal of organic growth reveals a degraded, more absorbent surface
b) Simple removal leaves behind spores and roots, invisible to the naked eye
This is why people observe “I cleaned my roof but the moss grew back twice as fast”. The process may be likened to cultivating a field for a new crop!
It is therefore helpful to think of the roof cleaning process, more in terms of kitchen hygiene. You can wipe spilt food with a damp cloth, but if you want to sanitise the surface safely, you also need anti-bacterial spray. Bio-Wash Roof Cleaner is that surface sanitiser, killing the invisible roots and spores embedded in the porous surface of your roof, suppressing the re-growth.
Used as an annual maintenance treatment, it prevents moss from building up to concentrations that can damage a roof.
However, it is more commonly used as a roof cleaning pre-treatment for:
• Kingfisher Kolourseal (Preventing re-growth underneath coating)
• Kingfisher Pointing Solution (Re-pointing of ridge tiles and verges)
• Kingfisher Asbestos sealer and primer
• Kingfisher Asbestos roof coating
• Kingfisher Extreme Climate (re-sealing roof tiles invisibly)
In all of the above scenarios, correct application of Bio-Wash Roof Cleaner improves adhesion and longevity of the protective treatment or repair, by effectively sanitising the surface.
How to use
No preparation is necessary but make sure that the roof surface to be treated is fairly dry.
Bio-Wash Roof Cleaner concentrate should be diluted 1 part Bio-Wash with 4 parts clean water. Apply using brush or low-pressure pump sprayer (typical garden weed sprayer) and ensure thorough surface wetting.
There are two ways of using the product:
a) As a surface neutraliser (After pressure washing).
With the growing popularity of and wide access to, powered pressure washing equipment, surface biocides are frequently used as a post-cleaning surface sanitiser. Even the most thorough pressure washing leaves microscopic roots and spores within the substrate, joints and crevices, which can rapidly re-grow into moss/mould if left untreated.
Liberally apply Bio-Wash by brush or low-pressure pump spray (not atomiser) to render the surface organically inert as a pre-treatment for subsequent application of the appropriate Kingfisher surface coating or repair.
DO NOT RINSE OFF. Leave until the Bio-Wash has dried in or for a minimum of one to two hours before subsequent coating.
Note: NEVER load Bio-Wash Roof Cleaner into the pressure washer soap reservoir for application under pressure.
b) As an effective moss & mould treatment (without pressure washing)
For very heavily moss or mould contaminated surfaces which cannot be pressure washed, e.g. asbestos cement roof sheets. Bio-Wash Roof Cleaner kills the organism, undermining its structural adhesion to the substrate, making it easier to remove heavy accumulations.
Apply liberally over the entire area by brush or low-pressure spray (not atomiser) and leave for 7 days (DO NOT RINSE OFF), before brushing, scraping or soft hosing the surface clean.
DO NOT apply at air or surface temperatures below + 6 °C.
How much will I need?
It depends on the size of the project. One 5 litre container will dilute to treat up to 125 sq m which would generally treat the roof of an average 3 bedroom detached home.
a) Avoid contact with metal or anodised finishes.
b) This class of biocides relies on U.V light activation. You will therefore achieve more consistent results with spring / summer application than in winter.
c) Never load Bio-Wash Roof Cleaner into the pressure washer soap reservoir for application under pressure.
d) If working at height ALWAYS seek the advice of a competent roofing professional or H&S adviser, before commencing works.
As always we recommend that you read the Technical Data Sheet & Safety Data Sheet thoroughly before commencing any work. If in doubt please call us for advice, we are here to help.
|Action Period (Pre-wash surface)||30 minutes to 4 hours|
|Application Temperature||+60C to +350C|
|Service Temperature||-200C to +500C|
Kingfisher Bio-Wash is a deep penetrating, broad spectrum biocide (of a category sometimes described as fungicidal wash), designed to give quick and efficient removal of all moss, green mould, algae or lichen from a wide range of outdoor, mineral based surfaces such as walls, paving, patios, roofs and driveways. Supplied as a concentrated liquid, one 5 litre container diluted, makes 25 litres of ready-to-use cleaner, which will treat up to 125 sq.m.
Bio-Wash is easy to use and an essential pre-treatment, prior to the application of any of the Kingfisher range of masonry water seal, paving resin, roof coating and masonry paint. It is available in either READY TO USE or CONCENTRATE form.
Companion / Related Products:
• Kingfisher Kolourseal
• Kingfisher Asbestos Roof Coating
• Kingfisher K-Seal, Restore-A-Drive, Ultimate Topcoat, Imprintseal, Blockstar, Indian Sandstone Sealer
• Kingfisher Extreme Climate, Stormseal, Superseal
• Kingfisher Weatherflex
• Kingfisher Coloured Pointing Mortar
• Kingfisher Eco-brick Cleaner
Refer to these individual product data sheets for detailed application guidance published on our website
To eradicate damaging moss and other organic matter from, and also to retard its re-growth onto, the following surfaces:
• Concrete & Clay Roof Tiles
• Asbestos cement roof sheet
• Slate roofs
• Sandstone & Limestone
• Concrete paths & yards
• Paving including: man-made flags, blocks and natural stone
• Wall both brick & stone
• Mortar joints
If in doubt, please call our technical services department on 01229 869 100 for guidance.
• Ease of application by brush or low-pressure spray (non-atomising) (SEE APPLICATION FOR LARGE AREA SPRAYING)
• Versatile application
• No rinsing required
• Kills the moss and mould spores/roots which weed-killers do not
Hard surface biocides are increasingly used in conjunction with powered pressure washers in both commercial and domestic settings, to clean or prepare surfaces for various types of decorative or protective coating. In that sense therefore Kingfisher Bio-Wash is THE surface preparation! Often no preparation is necessary, providing the surfaces to be treated are fairly dry and free from “ponding” water.
For paved or tarmac areas, if there are weeds(broadleaf/grass) as well as moss, these should be sprayed first with a premium grade weed killer as directed.
Asbestos cement roofs contaminated with moss are often at significant height above ground and should typically be surveyed by a competent industrial roofing professional before treatment. They can be fragile and require non-destructive cleaning methods (precludes pressure washing), as well as the expertise to identify potential structural issues and establish safe working protocols including access for the surface preparation phase.
The concentrate should be diluted 1 part Kingfisher Bio-Wash with 4 parts clean water. Also available as Ready to Use. Apply using a brush or a low-pressure pump sprayer (typical garden weed sprayer) or for larger areas a non-atomising sprayer. This includes most “General Purpose” manual pump sprayers and powered airless sprayers (e.g. Graco) with the following set up: Pressure adjusted to Ca. 1000 psi, nozzle size 14 thou (Graco: 514). One coat should normally be sufficient when used as a primer but when used as a stand-alone sealer in exterior applications, two coats are usually preferable. and ensure thorough surface wetting.
a. As a Surface Neutraliser (after pressure washing): Even through pressure washing leaves microscopic roots and spores within the substrate, joints and crevices, which can rapidly re-grow if unchecked. Liberally apply Kingfisher Bio-Wash to thoroughly sanitise the surface as a pre-treatment for subsequent application of the appropriate Kingfisher surface coating. DO NOT RINSE OFF. Leave until the Bio-Wash has dried in or for a minimum of 1 to 2 hours before subsequent coating.
b. As an Aggressive Moss & Mould Inhibitor (without pressure-washing): For very heavily moss or mould contaminated surfaces, which cannot be pressure washed, e.g asbestos cement roof sheets, soft sandstone walls, soft bricks etc. Apply liberally over the entire and leave to activate or at least 7 days before brushing scraping or soft hosing the surface clean. NOTE: If scraping dead moss from asbestos cement roof sheets, ensure the surface is damped with water to prevent fibre release and wear the recommended PPE for WORKING WITH ASBESTOS, including gloves, face mask and coveralls.
DO NOT apply at air or surface temperatures below +6°C.
There are some situations where a surface has been contaminated for a protracted period of time and this can result in deep staining of the substrate. Some lichens for example will resist even powerful pressure washing with turbo or rotary jet nozzles. In such cases we recommend contacting our technical services department as there are too many variations to list here.
Brushes and sprayers can be cleaned in warm soapy water.
5 litres of Concentrate treats: 125 sq.m (when diluted with 20 litres of clean water)
1 litre of Concentrate treats: 25 sq.m (when diluted with 4 litres of clean water)
5 litres of Ready to Use treats: 25 sq.m
25 litres of Ready to Use treats: 125 sq.m
Kingfisher Bio-Wash is supplied in 5 & 25 litre plastic containers
Shelf Life & Storage
The product has a shelf life of 12 months unopened from the date of manufacture, subject to correct storage conditions. Store upright in original sealed packaging in a cool dry place, out of direct sunlight Keep out of reach of children.
a) Whilst Kingfisher Bio Wash is not a weed-killer, in very dry conditions it may temporarily burn or discolour grass & broadleaf vegetation. Take care to avoid overspray when treating paths or driveways adjacent to lawns. A simple protection is to lay a broad plank of wood along the grass edge to catch the overspray.
b) Avoid contact with metal or anodised finishes.
c) This class of biocides relies upon U V light activation. You will achieve more consistent results with spring/summer application than in winter.
d) Never load Bio-Wash into the pressure washer soap reservoir for application under pressure.
Health & Safety
This product is classified as an irritant and users should avoid splashing when handling the product and wear appropriate protective clothing, impervious glove and eye protection during application. Inc case of contact with skin or eyes rinse the affected area immediately with copious amounts of clean water. Repeated/prolonged contact with the skin may cause sensitisation. Should irritation persist seek medical attention. Keep children and pets away from treated area until the Bio Wash has fully dried.
• If applying by spray wear a face mask, disposable gloves and coveralls
• Avoid contact with skin and eyes
• If contact occurs wash immediately with plenty of water
• Keep out of reach of children
• Ensure good ventilation during application and drying
• Always dispose of empty packaging responsibly
This product is non-flammable.
Before using this product read the Material Safety Data Sheet which can be obtained at
www.kingfisheruk.com or by calling the Kingfisher Technical Dept. Tel: 01229 869 100.
The information given in this product data sheet is given in good faith, based on current knowledge and experience. It relates only to the specific material designated and may not be valid for such material used in combination with any other materials or in any process. Such information is to the best of the company’s knowledge and belief, accurate as of the date indicated.
All recommendations are made without warranty or guarantee, as to accuracy, reliability, completeness since the conditions of use are beyond our control. It is the user’s responsibility to satisfy themselves as to the suitability and application of such information for their own use.
tiled roof moss removal
Easy to use guidance notes on mixing ratios and application. This was applied to a tiled roof that had a well established carpet of moss over a significant area of the roof, you could see the difference after 7 days prior to washing.
Reviewed by Peter Manson
Kingfisher Moss Killer
Killed all the moss on our crazy paving paths - like a strong weed killer but for moss. Quick delivery and informative web site.
Reviewed by Wendy