In this article, I would like to discuss cleaning natural stone patios with and without the use of chemicals. 

The most environmentally friendly way of cleaning your patio is using just water and a pressure washer. If water is not sufficient to clean the stubborn stains, then Natural Stone and Timber have products on the shelves in our stores such as New Clean 60 patio cleaner and Rust Off. These products are generally water based and do not have many detrimental effects to the environment, but for best practice try to reduce chemical usage where possible.

The Test

In this test we have cleaned Silver Latte Travertine Paving slabs, which is an extremely dense paving material and dirt and grime do not easily penetrate the surface of the stone. In the images below you can see that the paving looks very dirty and you can no longer see the beautiful natural patination of the Travertine Paving. Even though this paving looks extremely worn and stained, due to its naturally high density its going to be very easy to clean off, this means that there would be no need for a chemical cleaner. These cleaners are generally used on more porous stones such as Indian Sandstone paving where the dirt is more likely to penetrate the surface of the stone and become more difficult to remove. 

The same would also apply to all Porcelain Paving Slabs and most types of Limestone Paving as these also have very low porosity levels and it would be very unlikely that you would need to use a chemical cleaner on any of these products unless you have stains from spillages or from metal furniture.

You can see in the below images this patio had not been cleaned for some considerable time and there was a large amount of build up of dirt and even some areas of moss forming between the paving slabs. 

Cleaning Natural Stone

On this area which is about 45 square metres in total, including a few areas not shown in these images, this took a total of 45 mins to completely clean.  Using pressure washer alone you can see in the above image, so as a rule of thumb allow 1 minute per square metre and possibly more if the stains are particularly bad. 

Some care needs to be taken not to damage the pointing product between the slabs, which in this case was Easy Joint in Stone Grey. If you concentrate too much pressure directly onto the pointing materials it can be damaged and start to lift.

As you can see from the above two images, the travertine paving was successfully cleaned back to its original state without the need for any chemical cleaners, this is good for the bank balance and also good for the environment. If you find that after numerous attempts to clean your Natural Stone Paving Slabs that some of the staining is not lifting, you should then look to a chemical cleaner such as New Clean 60 or if you have rust marks left on the surface of the stone you should try Rust Off all available to purchase online or through one of our branches.

If you are looking for paving products that are easier to clean and that require less maintenance, always go for the denser products such as Travertine Paving, Porcelain Paving, Indian Limestone Paving, Slate and Granite Paving. Other less dense products are in no way inferior and will always clean back to their natural state but you may need to spend a little more time to achieve this and you will also require some chemical cleaners if you are looking for the perfect results.