Our blog is designed to offer

you valuble information about

our pioneering cleaning systems.

For more information please

do not hesitate to contact us.

Why is my stonework turning black? - Stone Restoration




Over time all properties will show their age, which can be a beautiful thing but should not be ignored. Stone turning black can be attributed to a variety of factors, with pollution and algae emerging as primary culprits.

Why Is My Stonework Turning Black?

Are you starting to notice some black patches or mould-like growth on your stone? Whether that be your stone patio, stone ledge or stone walls, it's an unpleasing visual inconvenience but a very common problem. While these black stains don’t necessarily damage your stone surface, mould spores and pollution stains are unwanted and ugly. 

Leaving this problem untreated, will lead to the spread and growth of the discolouration. It’s advised that you get a specialist to treat and restore your stonework as soon as the problem is first noticed.



Pollution is a relentless force in urban landscapes that can leave marks on your property's stonework. Airborne pollutants, such as particulate matter and industrial emissions, settle on the surface of the stone, gradually forming a dark patina. Over time, this accumulation creates a sombre, blackened appearance, robbing your stone features of their original character.


On the other hand, the presence of algae introduces a living element to the equation. High moisture environments like facades near foliage or buildings with damaged guttering provide the perfect breeding ground for these microscopic organisms. As algae increase on the surface of the stone, they not only alter its colour but also compromise its structural integrity. The result is a transformation from the beauty of natural stone to a gloomy shade of grey or black.

At Spectrum, we understand the significance of maintaining the aesthetic appeal and structural integrity of your property's stonework. Our expert team specialises in external building services, including stone cleaning and restoration. By addressing the root causes of discolouration, we can breathe new life into your stone features, ensuring they stand as proud and vibrant elements of your property again. 

How Can I Get Rid of These Black Marks?

To restore the natural beauty of your stone features, it's crucial to approach the cleaning process with care. While DIY methods may seem tempting, seeking professional guidance ensures the best results without risking damage to the stone.

For effective and safe stone cleaning, Spectrum recommends the use of the innovative DOFF cleaning system. This high-temperature steam-based method not only removes black stains caused by pollution and algae but also eliminates other deep-seated contaminants. The DOFF system provides a gentle yet thorough cleaning process, preserving the integrity of your stone while ensuring a pristine finish. Professional technicians at Spectrum are well-versed in the intricacies of stone restoration, employing the DOFF system to rejuvenate your property's stonework. Trust in the expertise of Spectrum to unveil the original beauty of your stone features, leaving them revitalised and resistant to future staining.

Get in touch with us today to arrange your free quotation and start the transformation of your stonework.

Spectrum’s Approach


A History Of Success


Our team of stonemasons can restore your stone facade back to its former glory, so don’t worry if your discoloured stonework looks ‘unfixable’ - we can assure you that these defects are completely reversible.


Creative Access Solutions


We are renowned for our cost-effective access solutions. We take pride in all of our specialists being IRATA trained - meaning that we cut the costs of scaffolding. Learn more about our abseiling services here. 


We can access the most complex buildings smoothly and keep within your budget. 


So if you think that the stone element on your property is out of reach and can’t be properly cleaned and restored? Think again. 


Reporting and Results


After each project, we deliver the client a full report containing images and videos of the finished surfaces, along with any other advice and information regarding the maintenance go your building. 



Get in Touch


Contact our friendly team with any queries that you may have regarding stonework.


Or give us a call on 020 3551 6206. 




Back to Blog Posts

Read Our Stone Cleaning Blog

How to Clean Statues

17th June 2021

Why Does My Render Look Dull?

14th July 2021

A Property Manager’s Guide to a Stone Cleaning Service

17th March 2021

Rope Access in London

8th November 2022

What is Brick Repointing?

10th March 2021

What Are the Stains On My Brick?

3rd June 2021

How Can Rendered Walls Be Accessed?

4th August 2021

The Ultimate Guide to Softwashing

26th August 2021

Maintaining Render to Meet Property Regulations

8th July 2021

What Is Rope Access?

6th May 2021

Can We Help With Your Specialist Building Cleaning and Restoration Needs?

Call Us On:

020 3551 6206

Email Us On:

We Cover The WHOLE Of The UK!