The following photos show a large black limestone patio that had been installed at a house in the village of Walgrave by a local builder who had sealed the stone before cleaning it first. Doing so trapped the dirt and grout smears (ka grout haze) underneath the sealer which resulted in a hazy appearance that could never be cleaned off.
Spring is an ideal time to work on patios which tend to get stained most from leaves and other detritus during the windy autumn and then ravaged by the winter frosts. If you want to seal the stone though its best to wait until a spell of continuous hot weather for the best results.
Cleaning a Black Limestone Patio
To clean the stone, I would first need to remove the builder’s sealer, so I started by applying Tile Doctor Remove & Go which is a strong product designed to safely remove coatings such as sealers and paint from stone and tile. A strong dilution of Remove and Go was applied to the floor and left to soak in for about ten minutes before being worked into the Limestone using a black scrubbing pad fitted to a rotary floor scrubbing machine. The soiled cleaning solution was then rinsed off the patio with water and extracted using a wet vacuum.
With the sealer removed along with the dirt then next task was to tackle the smears of grout that had been left on the surface of the stone. To do this I applied a specially developed product called Tile Doctor Acid Gel which is left to dwell on the surface of the stone just long enough to weaken the unwanted grout which can be then scrubbed off. The solution is then rinsed off the patio and extracted as before. This process was done in sections worked across the length of the patio and then when finished it was given a through rinse.
Sealing a Black Limestone Patio
I would need the limestone patio to be dry before sealing so I left it fully dry out over the course of a few days before coming back to finish off, fortunately the weather was good, and it wasn’t long before I returned.
My sealer of choice for Black Limestone is Tile Doctor Colour Grow, it’s an impregnating sealer the penetrates the pores of the stone protecting it from within and simultaneously enhancing the natural colours in the stone. This product is also fully breathable which makes it ideal for external use or damp areas where moisture needs to rise through the stone and evaporate. Two coats of Colour Grow were all that was required to fully seal the stone.
The work was a huge improvement to the look of the patio which is now vibrant, inviting and fully transformed by the process.