As we move through autumn, stone and porcelain paths and patios can become increasingly slippery and potentially very dangerous. The slippery residue is generally caused by algae – a natural organism that settles onto surfaces and thrives in damp environments and shady spots. As well as creating a slip hazard, the deposits can discolour surfaces. It’s well worth addressing the problem before winter sets in; slimy residue will only attract more build-up and make the problem worse. Treatment is fast and easy – but it’s essential to use the correct product, rather than dosing the area with more water.
Different types of algae
The term algae includes cushion-like moss, Liverwort, which is a flat green growth with tiny leaf-like lobes, and Lichen, which is more crust-like and can be yellow or orange. Jelly-like growths are also common; they’re often black or dark green and these are caused by a cyanobacteria called Nostoc. None of these growths are hazardous – infact, Lichen is particularly common in areas with clean air, so its appearance can be a positive sign – but slippery hard surfaces can be.
Another common problem is black spot – a speckle-like deposit that can infact be black or white. Black spot is a dust-like lichen that originates from plants and trees. It colonises on pavers, sending tendrils or ‘hyphae’ down into any cracks or porosity, searching for nutrients. It takes about 2-3 years to become established below the surface and it creates a slippery residue on the surface of pavers.
What not to use on slippery paths
A pressure washer and a dose of household cleaner is a common go-to solution for slippery pavers. However, excessive water only makes conditions even better for algae to flourish and pressure washing can damage the surface of the pavers, any sealer applied and it will loosen grout. Water also won’t target hyphae or filaments anchored into place below the surface. A specialist approach is necessary to effectively remove residue and microspores below the surface. Any treatment used needs to break-down the slippery residue, have a bleaching action to restore the colour of the paver and target growth below the surface.
How to treat slippery paths
Care should be taken in selecting a suitable treatment. If a solution is acidic, it will damage acid sensitive material and erode the grout joint. We recommend ECOPROTEC Black Spot & Algae Remover which can be safely used on all types of natural stone, concrete, brick and porcelain. This treatment removes all types of organic residue, slippery matter and stains, breaking down hyphae below the surface, as well as preventing regrowth. When applying the remover, it’s also important to treat the whole area of paving, for a uniform appearance.
Before applying any treatment, large, mossy deposits should be removed. A long-handled block paving brush is a useful tool. The whole area should then be swept clean to remove other residue, dirt and leaves. ECOPROTEC Black Spot & Algae Remover is then applied neat to swept pavers, using a watering can or light pressure garden spray, where it fizzes during treatment. It should be left to act for 2-4 hours and surfaces then hosed with clean water. The solution can be used on dry and slightly damp surfaces and should be applied during a morning or afternoon of fair weather.
ECOPROTEC Black Spot & Algae Remover
Pets should always be kept away during applications of cleaning and sealing products – throughout the whole application process and, in terms of cleaning, until surfaces have been properly rinsed. If undiluted solution comes into contact with plants, etc, they should be rinsed off with plenty of clean water. When surfaces are being rinsed off with a hose or watering can, as part of the application process, then any residual product will naturally degrade.
After treatment, it’s worth protecting the surface; we recommend ECOPROTEC Patio Sealer for natural stone and barrier treatment, ECOPROTEC Pre Grout Protection, for matt porcelain pavers. Both will help prevent the absorption of moisture and organic particles, reduce staining and the spread of algae.
To find out more about ECOPROTEC® treatments and to request free samples, please call 01823 662722, email technical@ecoprotec.co.uk or visit www.ecoprotec.co.uk
