How to remove algae / moss from Indian sandstone jointing?

For your quick solution, Patio and Concrete 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 http://www.amazon.co.uk/Just-Green-CONCRETE-PATIO-CLEANER/dp/B000O5I2Y2 You first have to look at what causes them to grow. Is the area damp or shady? Poor drainage is usually the main cause.Other ways of control and prevention can vary: 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. I hope this will prevent any slips or trips.

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