I was asked to survey a Limestone floor at a property in Underriver which is a very rural locality close to Sevenoaks in Kent. The Limestone tiles had been laid throughout the lower ground floor and it was clear to me that the protective sealer had worn off completely allowing dirt to become ingrained in the stone and especially the grout which had turned black.
I understood from the owner that the grout lines should have been a pale cream colour rather than the black it was now. We discussed the process of restoring the floor including the grout, and I gave them a quote for the work which they were happy to accept.
Cleaning a Limestone Tiled Ground Floor
Our first job was to tackle the severe soiling in the grout lines. To do this a strong dilution of Tile Doctor Pro-Clean was applied to the floor and left to soak into the stone and especially the grout for about 20 minutes. This was scrubbed in with help from a rotary buffer machine fitted with a soft/medium long-bristled nylon brush.
The resulting slurry was then rinsed with clean water and vacuumed up. I repeated the process in a couple of areas that were particularly heavily soiled. I then spot checked the grout lines and completed the clean with a wire brush and more Tile Doctor Pro-Clean.
With the grout issue resolved I turned my attention to the Limestone tiles for which I used a set of Diamond burnishing pads. Work started with a coarse 400-grit 17” diamond pad fitted to a rotary buffing machine. Then 800 and 1500 grit pads in sequence using water to lubricate the process. The resulting slurry was rinsed off the floor with water after each pad and the soil extracted using a wet vacuum. The floor was then left to dry thoroughly overnight.
Sealing a Limestone Tiled Ground Floor
Returning the next day, the floor was thoroughly vacuumed removed to remove any remaining powder and grit left over from burnishing. This was then followed by applying the last pad in the set which is very fine 3000-grit diamond polishing pad. This last pad really brings up the polished appearance of the limestone, only a little water is used during this action, it’s a process we call a spray burnish. Once done the floor was clean, dry, and ready for a new sealer to be applied.
I had discussed the appearance of different sealers with the customer previously and for this installation we went with Tile Doctor Ultra Seal. It’s a premium penetrating sealer that soaks into the pores of the stone protecting it from within, additionally Ultra-Seal doesn’t alter the natural appearance of the stone giving it undetectable protection from staining.
The whole area was then buffed using a white buffing pad.
The customer was delighted with the result and will use Tile Doctor going forward to keep the floor protected. We offer an annual maintenance plan for just this, we can return each year and ensure that the floor is kept in tip top shape.
For day-to-day cleaning, I recommended using Tile Doctor Neutral Tile Cleaner, it’s a mild pH neutral cleaning product that and will keep the floor maintained and won’t impact the sealer which can be a problem with stronger products.
The reason grout goes dark is because the cementitious top layer was not been sealed by the installer, as a result the dirt from the tile gets washed into the recesses of the grout line during cleaning where it gets stuck.