Bio-Wash Moss Remover  

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29.87Inc. VAT24.89Ex. VAT
Product Code:72

Bio-Wash Moss Remover, is the maintenance professional’s choice for controlling troublesome moss growth on exterior hard surfaces like tarmac driveways, block pavers, sandstone paving slabs, concrete slabs, walls and much more. Read More

Coverage:5L makes 25L, treats 125 sqm
Application:Garden Sprayer / Deck scrubber
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Bio-Wash Moss Remover

Stop the moss, Stop the damage!

Bio-Wash Moss Remover 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 walls and paving.

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 for water-seal, masonry paint and paving resins.

Bio-Wash Moss Remover is sometimes equated to “weed killer”, but this is an error as the biocide you need to kill a dandelion is completely different to that needed to eradicate moss.  Nevertheless Bio-Wash Moss Remover is a synergistic “broad spectrum biocide” which means it simultaneously targets, kills moss and a whole lot more, including; green mould, black mould, lichens and algae.

Applications include:
•    Removal of moss, algae and lichens from external walls & paving
•    Cleanses: concrete, brickwork, cement mortar joints, man-made paving, concrete blocks
•    Tarmac driveways, paths and roadways
•    Sandstone walls, limestone, slate & granite 
•    Halts the deterioration of mortar joints, caused by invasive moss
•    Restores the colour of organically stained brickwork and stone
•    Improves adhesion quality of decorative coatings


How does it work?

As with so many aspects of property maintenance, “a stitch in time” really does “save nine” when it comes to controlling moss and mould growth.  

Moss, mould and algae are persistent and often destructive house guests, as they all contribute to either decorative or physical deterioration, of the surface to which they have attached themselves.  

Left unchecked in mortar joints for example, moss breaks down the mortar in two ways:

a) Chloride erosion
The root system of the moss gradually loosens the surface and the organism retains moisture up to 16 times its dry weight, so that the mortar joints take much longer to dry out.  Additionally, this semi-permanent moisture encourages the emergence of corrosive salts which are naturally present in the damp mortar and adjacent brick or stonework.  These salts are corrosive to mortar and accelerate the erosion of mortar joints, which might otherwise have survived for decades.

b) Freeze/thaw erosion
In winter the moisture laden moss freezes along with the moisture it has trapped in the mortar joints underneath.  This has the effect of rupturing the surface of the mortar joint as the freezing water expands to form ice, which in turn permits deeper water penetration, worsening frost cracks and ultimately leading to complete failure of the mortar joint.

Used as an annual maintenance treatment, Bio-Wash Moss Remover prevents moss from building up to concentrations that can damage buildings and hard landscaping.  It can be spray applied with a low-pressure pump sprayer, just as used for garden weed spraying, which allows very large areas to be treated in a short space of time.  This approach is highly recommended for tarmac and paved areas with low traffic or under tree canopy where green mould in particular thrives.

However, it is more commonly used as a pre-treatment to remove organic materials including moss, mould and lichens from stone walls, brickwork and paving in preparation for:

•    Water-seal or surface water repellent coating on walls
•    Re-pointing of weathered and organically contaminated masonry
•    Re-rendering of earth-retaining walls
•    Re-decoration with masonry paint
•    Refinishing paving with a resin sealer

In all of the above scenarios, correct application of Bio-Wash Moss Remover improves adhesion and longevity of the protective treatment or repair, by effectively sanitising the surface.  It enhances the substrate stability and in that sense is an absolutely essential part of the preparation required to make the paint, resin, mortar or water seal, bond to the substrate.  Nobody wants to see lichen or moss de-laminating a costly paint finish, 6 months after application!


How to use

Surface Preparation

No preparation is necessary but make sure that the surfaces to be treated are fairly dry and free from “ponding” water or puddles.

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.


Bio-Wash Moss Remover 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 mortar.

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 Moss Remover 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, friable sandstone walls, soft bricks etc.

Apply liberally over the entire area by brush or low-pressure spray (not atomiser) and leave for 7 days 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 is approximately two average U.K driveways.



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 Moss Remover into the pressure washer soap reservoir for application under pressure.


Technical Support

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.

Always satisfied.

Used this product for a number of years. Highly effective.


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Worked very well on my garden shed despite raining an hour later


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