How To Clean Your Natural Stone Patio

Posted on: 27 August 2015

A natural stone patio will last for decades and for that reason is often the popular medium chosen by patio builders.  Although durable, natural stone does need cleaning from time to time to keep it looking its best. There is definitely a knack to removing different kinds of stains like grease and lichen, for example. 

Here's how to clean your natural stone patio.

General cleaning

Begin by getting rid of any loose soil, sand, leaves or other surface debris from your patio.  To do this, use a stiff yard broom and sweep the whole surface of the patio.  Make one vertical pass and one horizontal pass to make sure that you get rid of any dirt that might drop into the cracks between the patio stones.

Use a hosepipe with gentle pressure to wash down the patio.  This will get rid of any residual dust that's left after you've swept up.  It's not advisable to use a pressure washer as this can damage the mortar between the patio stones.

Now that you can see the stones, have a look over the patio for any stains or marks.

Barbecue stains

If you have a barbecue set up on your patio, you may find quite a few stains in the vicinity left by spilt food and drinks, cooking grease and soot.  These marks can all be removed easily using the same technique.

Squirt a generous dollop of washing-up liquid over the stains and scrub it using a soft deck scrubbing brush and warm water.  Washing-up liquid contains ingredients that are particularly good at removing grease and food colouring, whilst being mild enough not to damage the natural stone.  Use your hosepipe to rinse the area with clean, fresh water and check that the stains have all gone. 

You may need to repeat the exercise to get rid of deeply ingrained grease marks. 

Biological stains

Natural growths like mildew, lichen or moss can leave unsightly black marks all over your stone patio.  Fortunately, they can quickly be dispatched using a mild solution of warm water and household bleach.  Use thin bleach, rather than a thick clinging one that can be hard to remove and which may damage your stone.

Make a solution using a ½ cup of bleach to 10 litres of water.  Wear rubber gloves to protect your hands when preparing the bleach solution and add the bleach to the water not the other way around.  This reduces the danger of getting splashed with neat bleach.   

It's essential that you treat the whole patio area, not just the spots affected to make sure you kill off any plant spores that might be lurking in between the stones.  Don't apply bleach to dry stone as it could cause fading.  Wet the patio first, and then apply a generous dressing of the bleach solution.  Use a stiff deck brush to give the whole area a thorough scrubbing to get rid of the marks.  Rinse thoroughly to remove any traces of bleach.

You may have to repeat the exercise a few times to get rid of the lichen marks completely.  Never use neat bleach on your natural stone patio as this can cause severe patchy fading and could ultimately damage the stone.

In conclusion

Your natural stone patio should be cleaned thoroughly at the end of the summer and spring-cleaned before you begin using it again after the winter.  This will help to keep the stone in good condition and prevent any biological growths from becoming established.

For more information on stone patios, contact a company like Allweather Shelters.