What is the correct way to remove cement stains from natural stone?

Cement stains are a common occurrence on natural stone patios, but we are here to help.

This client’s patio was unfortunately damaged due to cement spillages not being cleaned up after installation.

The contractors did not remove the remaining cement stains from their work area correctly and our customer thought their patio was ruined. In their attempt to remove spilled cement (2) they have caused rust staining (1) by using the wrong product for the job.

Natural stone surfaces are versatile, hardwearing and beautiful products to use and investing in them will add character and value to your home. Generally, natural stone is very easy to care for but there are a few things to keep in mind when choosing cleaning products to use on them.

*Please note – never use brick acid on natural stone surfaces.

Why is brick acid the wrong product to use on natural stone?

Brick acid is very harsh, extremely corrosive, and on certain stones will cause chemical reactions that will result in severe rust staining, spoiling the appearance of your stone patio or floor. The high content of hydrochloric acid in brick acid means it is not suitable to use on stones like sandstone, limestone, granite and slate. Not only will it damage the surface, but it will also draw iron deposits from within the stone if they are present. Some stones are more susceptible to iron staining than others. However, in the example above you can see that the use of brick acid on Kandla Grey sandstone has created a strong reaction. This has caused the iron to leach to the surface and leave a strong yellow stain on the stone.

The client now needed a product to remove the rust staining that has occurred after the wrongful use of brick acid. They also needed an effective cement remover for the remaining cement spillage on their patio.

What is the right product to use on natural stone to remove rust stains?

To remove the rust stains from the client’s patio, we recommended Rob Parker’s Best Rust Remover. This product removed the orange-brown deposits that had appeared on the surface, as a result of the brick acid being used. Rob Parkers Rust Remover is easy to apply. You just need to use a paint brush to apply to the stains and leave for up to 15 minutes, then rinse thoroughly. This can be repeated until the staining disappears.

It is important to note that iron deposits can sometimes leach out from stone surfaces naturally, as well as when brick acid has been used. The use of certain lawn feeds and weed killers also contain ferrous sulphates which can cause the leaching of iron deposits from natural stone too. We recommend washing away any spillages of feed/weed treatments promptly to avoid staining.

Read another of our blog articles here, to find out how to remove rust staining from a Kandla Grey patio in the most effective way.

What is the best product to remove cement spills from natural stone?

For the removal of cement spillage on natural stone, we recommend the use of:

Rob Parker’s Best Conclear is highly effective at removing cement stains and spillages and is ideal for use on natural stone surfaces as well as other substrates. Our Rob Parker’s Best product range has evolved from our 20 years of experience with natural stone. We wanted the products to address the common problems that people face such as rust staining and cement spillages.

This product has been formulated using a much gentler ingredient, glycolic acid. Whilst our product is manmade, it mimics the glycolic acid. This occurs in nature and can also be derived from cane sugar. The substance has low corrosivity, and is biodegradable, making it gentler on your stone and is kinder to the environment.

We are happy to report that the client was able to restore their Kandla Grey sandstone patio to its former glory, with our advice and Rob Parker’s Best products.

If you have any further questions or you would like to speak to one of our team, then please call us on 01844 279274. You can also email us at sales@stoneworld.co.uk and we will be happy to help. Alternatively, you can contact us by filling out the form down below.

Last updated: 16/08/2024