Black spots on garden patios are often caused by a persistent mold known as black lichen, which can be notoriously difficult to eliminate. Many homeowners instinctively reach for a pressure washer to tackle these stains, but high-end models can be expensive, unwieldy, and challenging to maneuver. DIY expert Sam Williams has introduced a practical and cost-effective method for rejuvenating paving slabs using simple household items.
Williams, from SGS Engineering, explains that black spots are actually a type of lichen spore that can be tough to eradicate. However, he suggests an easy solution involving common cleaning agents. “You don’t need specialized products to clean your patio,” Williams notes. “A mixture of washing-up liquid and warm water is highly effective. Just add a tablespoon of washing-up liquid to a bucket of warm water, pour the soapy solution over the patio, and scrub with a hard brush.”
For best results, Williams recommends scrubbing in a diagonal motion to minimize potential damage to the stone. For more stubborn stains, white vinegar can be helpful. However, it’s important to avoid using vinegar on sensitive stones like limestone due to its acidic nature. Instead, combine water and white vinegar in a 1:1 ratio in a bucket, apply the solution to the patio, and let it sit for 30 minutes to an hour before rinsing with a hose. If vinegar isn’t available, baking soda is a viable alternative, particularly effective against BBQ grease stains, though it may have limited impact on algae and mold.
While a pressure washer can expedite the cleaning process, caution is advised to prevent damage. If you opt to use one, move furniture out of the way and begin in the top corner of the patio. Hold the nozzle at a 30-degree angle and spray in a diagonal pattern, keeping the device at a safe distance from the slabs.
Williams emphasizes that patios generally require cleaning only once a year. Regular maintenance, such as brushing, especially during autumn, can prevent leaf buildup and persistent discoloration. Additionally, applying a patio sealant can protect against weathering and maintain the vibrant appearance of the slabs. This is particularly beneficial for newly laid dark slabs or after a thorough cleaning.
By following these straightforward tips, you can keep your patio looking fresh and well-maintained throughout the year.