Carpet Cleaning, Upholstery Cleaning, Hard Floor Cleaning, Driveway and Exterior Cleaning in Kent covering the following areas, Thanet, Ramsgate, Margate, Tonbridge, Tunbridge Wells, Sevenoaks, Sittingbourne, Isle of Sheppy, Faversham, Whitsable, Medway Towns, Canterbury, Folkestone and Dover.

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Algae, Lichen and Moss Removal


Algae: A green film or powdery deposit is typical of algae on paving, stonework and garden furniture. The dark green or blackish jelly-like growths that often appear in damper, cooler weather on paths and areas of tarmac are incorrectly known as blue-green or gelatinous algae, but are in fact Cyanobacteria.

Lichen: These are common on paving and timber structures such as garden benches. The colour of lichen varies with species, but most are silver-grey, grey-green, yellow or orange. They can be crust-like, leafy or scurfy in texture. They can also be found to be black in colour.

Moss: Mosses commonly found on hard surfaces where salts, soil and dirt have accumulated and are usually cushion-like.

Algae, lichens and moss are found in damp places as they need moisture for both growth and reproduction. Lichens are particularly common in areas with clean air. However, they grow only very slowly so, unlike moss and algae, are slow to spread.

Growth of algae, lichens and moss on paths and garden furniture often appears in sheltered areas overhung by plants.

Poorly drained and/or shady conditions contribute to the growth of algae, moss and lichen on paths and hard surfaces.

For areas where growths are a slip-hazard or are contributing to the weathering of wooden structures, the following controls are recommended.

Preventative Non-chemical control

  • Dislodge moss from between paving by running a sharp knife along the cracks. Alternatively, use a block paving brush with a long handle, narrow head and wire bristles for effective cleaning without stooping.
  • A pressure washer will remove moss and algae effectively.  However, use this method with care in areas where drainage is unsatisfactory as the extra water could exacerbate damp problems. Always wear goggles when using a pressure washer. This is the best method for removal of moss and algae from wooden garden features. After spraying, consider treating fences and sheds with wood preservatives and garden furniture with teak oil.
  • Brush hard surfaces with a stiff broom on a regular basis to help prevent growths from taking hold. Raking loose surfaces such as gravel helps to keep these areas free of both moss and weeds.
  • Prune overhanging plants to improve air flow - this will allow the drying effects of sun and wind to reach the site.
  • Ensure surfaces slope slightly to prevent standing water.
  • Improving drainage in the surrounding area will also help to deter growths. Dig out shallow channels along the edges of paths, patios and drives and fill with coarse gravel to absorb run off water.
  • Fork over beds close to damp surfaces to maximise drainage and water absorption.
  • Only pave areas essential for access. Choose permeable paving when constructing new hard surfaces and keep drains clear of leaves and debris.
  • Surface finishes that are raised to give grip in wet weather are ideal for shady spots. On wooden surfaces try tacking down some chicken wire as this too will make it less slippery. Spreading coarse sand over garden steps is another simple anti-slip solution.

Chemical control

Algae, moss and lichens can be removed with most proprietary patio cleaners. Most products are non-persistent and repeat applications will be required.

  • Use products based on pelargonic acid, acetic acid or nitrilo triacetic acid/trisodium salt which claim to control moss and algae on hard surfaces or natural paths. They may also give some control of lichens.
  • Just Concrete and Patio Cleaner is a natural surfactant (detergent) based on seaweed extracts and should be especially safe to use near planted areas. It claims to remove algae on hard surfaces.
  • Tar acids can still be used to control algae (but not moss) on hard surfaces.
  • Path and patio cleaners based on hydrochloric acid or bleach have some effect but are not recommended for use near plants. They can also discolour certain types of stone.

It is common to find growths such as algae, lichens and moss growing on hard surfaces. Contrary to popular belief, they do not damage what they are growing on, but can cause patios, drives, paths and steps to become slippery.

Removal of Black Lichen and Algae

England being a wet climate provides a good environment or black Lichen. Jet washing will rarely remove black lichen and can damage the substrate of the surface being jet washed. The removal of algae is obtainable via a jet washer but again care must be taken in order to maintain the condition of the substrate of the surface.

Algaecides are one method of removing Algae without the use of a jet washer. An algaecide is a chemical used for killing and preventing the growth of algae. Algaecides take a few days to work and therefore you will not see a huge difference the minute it is applied. They take up to two weeks to diminish, discolour and disappear. Algaecides may leave a light stain on the surface being treated however over time this will disappear. Please be aware that this does take time though.

A method of removing black lichen is to use a cheap bleach. The bleach will weaken the hold the lichen has on the surface. It can then be scrubbed or jet washed off. Please be aware that bleach is a dangerous liquid so considerations on where its being used, the surrounding environment and people around you must be taken. This form of removal is not recommended due to the dangers of working with the bleach.

Another method of removing black lichen is through the use of a biocide. In order to get rid of lichen you need to destroy the bond which provides the symbiotic relationship that the lichen needs in order to live.


Cleaning Services

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Carpet Cleaning
Upholstery and Curtain Cleaning
Hard Floor Cleaning
Wooden Floor Cleaning
Tile Cleaning

Patio and Pathway Cleaning
Driveway Cleaning
Wall, Fence and Garden Furniture Cleaning
Graffiti Cleaning and Removal
Decking Cleaning
Algae, Lichen and Moss Removal

Commercial Cleaning
Shop and Retail Cleaning

Flood Restoration Services
Fire Damage restoration cleaning