The unsightly red, green, or black staining on the exterior surfaces of your property and paths is likely due to the presence of algae, lichen, fungus or mould, or a combination of all four.

This can be a serious problem, which could affect the structure of your property as well as looking terrible.

Fortunately, modern soft washing systems using BENZ Biocides will keep your property clean and prevent build up.

This means that the surfaces around your home or business can kept clean for longer.


Self-draining surfaces like rendered walls and roofs will usually stay clean for three years before regrowth requires another treatment.

Horizontal surfaces like patios, decking, drives, and footpaths stay damp longer and so regrowth happens more rapidly. These will usually require an annual or biannual treatment to keep the growth under control and your property looking great all year round.

The annual cost of treatment is usually much less than power washing, does not damage your property, and the result is much longer lasting.


Moss on tarmac

Moss on a concrete tiled roof

Moss will normally start to appear around your property after about 7 years. It particularly loves to grow on tarmac and on concrete roof tiles. On many buildings moss will start to grow on the roof, spread from the roof to the gutters, and then onto footpaths and drives. And it can spread very quickly.

Moss holds water, which can add weight to a roof causing stress on the structure. It expands when frozen causing damage to gutters and becomes extremely slippery on footpaths, driveways, and playgrounds. When treating moss we call it moss “control” as it is very hard to kill completely.

The best time to treat moss is from March to November. An annual or biannual application will protect your property and keep it looking great. It will also protect your property from the destructive effects of uncontrolled moss growth.

We use our own Health & Safety Executive (HSE) and Pesticide Control Service (PCS) approved, highly concentrated Biocidal Wash to control moss.

Tarmac will typically require two applications in the first year to bring the moss under control, thereafter a once yearly application.

Concrete tiled roofs last longer after treatment, from 5-10 years, before regrowth will be visible again and start causing a problem.


Algae on a slippery decking

Build up of algae on a path

Algae can be red, green, or black and will colonise exterior surfaces such as renders, concrete, timber decking, aluminium, and so on. A large build up of algae can look “grimy”, especially when its dormant as then the colour often changes to black or brown.

Algae is the number one cause of concrete paths looking dirty.

Historically, power washing or sodium hypochlorate (industrial bleach designed for sterilising milking parlours) was used to remove the grime. However the algae spores remained and quickly recolonised.

This meant the grimy appearance re-appeared after only 3-6 months, depending on the time of year. This disappointed many property owners, especially as power washing can be expensive. The net result was that some people began to leave cleaning their drives and paths until they got “really bad”.

Fortunately, using today’s modern soft wash systems with BENZ Biocides,  a 9-12 month application is enough to give all year round cleanliness, and freedom from growths.

Note: For suitable surfaces it’ s also possible to power wash to get an immediate clean look, followed up by a post treatment of BENZ Biocidesdes. This avoids the problem of rapid regrowth that used to be encountered when power washing alone was used.


Lichen dots on a roof

Lichen dots on a monoblock drive

Lichen are the round white, brown, and black spots that power washing alone cannot remove.  You’ll probably have noticed lichen on slate and concrete tiled roofs, as well as on concrete paths and monoblock drives.

Lichen grows into, and attaches themselves to, the surfaces of roofs and paths. The only way to remove lichen is to kill it and wait for the growth to release itself from the surface. This can take anywhere from 6 weeks to 6 months. A second application of BENZ Biocidal Wash after one month will speed up the process.


Phone Ben for a FREE quotation

087 90 90 918

Or click here to send an email