Your natural stone, like any other part of your garden or home, requires some periodic maintenance to keep it in tip top condition,
however this need not be time consuming or expensive. We have put together this guide to give you all the information you need to


The following is a guide only. The iron and  mineral content of natural stone can vary and therefore allchemicals must be tested on a small, inconspicuous area prior to full treatment. Always seek professional advice before applying any product to your natural stone.

Sealing is not generally required for Blue Black Slate, however in some circumstances it is recommended that Blue Black Slate is
sealed prior to installation with DRY TREAT ‘STAIN PROOF’. Examples of these circumstances are;

For best results, sealing should always be carried out by a trained technician. If you would like information or a quotation for London Stone’s pre-sealing service please let us know.

Brush the stone regularly with a stiff brush to remove any dried mud or dirt and prevent the accumulation of detritus in the joints. Occasionally leaves and other organic matter can leave a mark if allowed to decompose on the surface of the stone so it is important to ensure that any falling leaves are brushed away regularly.

Clean the stone as and when required (usually once or twice per year) with LITHOFIN ‘OUTDOOR CLEANER’. This product is a general cleaning agent and will also help to remove algae, light cement stains, organic stains, light efflorescence or picture framing and many other stains and marks. Always test cleaning products on a small area prior to full application. Before cleaning, sweep the stone to remove any loose dirt or detritus which could act as an abrasive agent when moved around the surface of the stone by the water jet. Then, following the instructions on the bottle, spray the product onto the surface of the stone, leave for up to 4 hours and then rinse clean with a jet-wash. This process may need to be repeated for stubborn marks. When using the jet-wash, be sure to select a medium pressure and hold the nozzle at least 500mm away from the surface of the stone in order to prevent the water jet from etching it.