This client called Tile Doctor to see if anything could be done about the colour of their limestone patio which was laid about 6 months prior at their house in Cheltenham. It and had always looked grey rather than the black they had expected and with summer on the way felt it was time to get it resolved.
I went over to survey the Limestone paving and could see straight away that whoever had installed it had not cleaned off the cement and grout residue afterwards. Add on top of that the green algae and dirt build-up you get over winter and the Patio was now looking very sorry for itself.
I conducted a test clean on a small area to work out the best method for restoring the appearance of the stone. The Limestone responded well to the test and it gave the customer the results he was looking for. Happy with the potential result and my quotation a date was booked for the work, although this was weather dependent. The job would take 3 days to complete.
Removing Cement and Grout from a Black Limestone Patio
We were quite fortunate with the weather and managed to find a few days without rain. Arriving on day one, the client had moved all the patio furniture out of the way, so we were able to get to work immediately starting with the application of a coarse 200 grit diamond pad fitted to a large buffing machine. The pad is applied to each paving stone in turn and lubricated with plenty of water. This action slightly mills the Limestone to remove all the old cement and grout that had been left of the surface. After rinsing with water and extracting the soil the process was repeated using a 400 and 800-grit burnishing pad to hone the stone and bring up its appearance. The area was quite large, so this took most of the first day.
Returning the following morning, we moved onto cleaning the grout lines using a strong dilution of Tile Doctor Pro-Clean. Then the whole patio was rinsed with water and scrubbed using a wet vacuum to extract all the soil generated. The patio was left overnight to dry out, the weather remained good, so we were able to come back the next day to seal it and complete the job.
Sealing a Black Limestone Tiled Patio
To seal the Limestone and restore colour I selected to use Tile Doctor Stone Oil, this is an easy to apply impregnating sealer, ideal for low porosity stone such as Limestone. Stone Oil is designed to enhance the colour and texture of stone, it also improves mechanical strength once it is cured.
One coat was applied to get the colour back in the stone, giving it the nice rich black it should have been. The stone was left to dry for two hours and then followed up with a coat of Tile Doctor Ultra-Seal to further seal the stone. Ultra-Seal is a no-sheen, natural-look, penetrating sealer formulated to provide maximum stain protection. It is also an excellent grout sealer.
As you can see from the pictures the results were fantastic and the customer was very happy that the patio now looked how they had expected it to when it was installed. The sealant should give it adequate protection from the elements but would need to be reapplied in future years. They were looking forward to making the most of the sunny weather and getting the barbeque out to make use of their lovely newly restored patio.