Acid Damaged | Stone Cleaning and Polishing Tips for Limestone Floors

The photographs on this page show the spot restoration of an acid damaged newly installed Limestone tiled floor at a medieval cottage in the historic town on Wokingham, Berkshire. It seems the customer accidentally spilled lime cordial on honed surface leaving dull stain spots on about six to eight tiles.

Acid Damaged Polished Limestone Floor Wokingham Before Restoration

After attempting to remove the damage themselves using a variation of different sealers the customer accepted defeat and contacted Tile Doctor to see if the issue could be resolved. If not, they were considering replacing the floor.

Acid Damaged Polished Limestone Floor Before Restoration Wokingham

Being the local Tile Doctor for the area I was asked to take a look and advise the customer. I explained that the dull spots had appeared because the surface tension of the limestone had been damaged from the citric acidic in the cordial. The affected tiles would essentially need to be re-polished; the customer was eager to see if I could resolve the issue and get all the tiles to be as uniform as possible.

Spot Polishing a Limestone tiled floor

My first task was to identify which tiles needed re-polishing with burnishing pads as once I got going it would be tricky to spot them; I did this by simply leaving post it notes on the affected areas.

To restore the appearance of the Limestone tiles I started with a 400 grit 3-inch pad fitted to a handheld flex machine. You can’t actually buy these 3 inch pads, they are found in the centre of the large 17 inch floor pads. The 400-grit pad is quite abrasive and needs to be applied with water to lubricate. I then followed the 4-stage burnishing process increasing the surface tension with each pad used this to leave the tile with a good sheen and most importantly a uniform appearance with the surrounding tiles.

Acid Damaged Polished Limestone Floor Wokingham During Restoration

The Burnishing pads are actually loaded with industrial diamonds and you apply them in sequence starting with the coarse 400 grit pad before moving onto the medium 800 grit pad, fine 1,500 grit pad and then finally the super fine 3,000 grit pad which really brings up the shine. You have to rinse with water between each pad to remove the slurry that is generated. The final 3,000 grit pad is applied with very little water and so the floor is dry when completed.

Spot Sealing a Limestone Tiled Floor

The last step was to carefully re-seal the tiles that had been burnished so they would blend in with the rest of the floor. I decided on Tile Doctor Ultra-Seal for this, it’s an impregnating sealer that doesn’t alter the colour of the stone leaving them with a natural look.

The process went well and was completed in around four hours, my customer was very happy with the result and left the following testimonial on the Tile Doctor feedback system

“We felt very comfortable with the recommended course of action and Mr Buckland inspired confidence so we were happy to let him get on with the remedy.”

Acid Damaged Polished Limestone Floor During Restoration Wokingham

Source: Limestone Tile Cleaning and Sealing Service in Berkshire

All carbonate materials, including those used in building and construction, are sensitive to acid deposition. A common example of this is the reaction that occurs when you combine bicarbonate of soda and vinegar. Another example of a material affected by this is Limestone, which is often used as tiled flooring. When exposed to acidic products, the damage caused to Limestone tiles is both material and aesthetic, and many property owners who suffer this kind of damage assume that they are beyond repair.

I was recently called to a property in Wapping, Central London, to take a look at a damaged Limestone tiled floor situated in a wet room. The surface of the stone had suffered heavily from corrosion due to the spillage of an acidic solution and the property owner was keen to see what could be done to restore the condition of the tiles. He had been told by another company that the floor was beyond repair, but I knew that with the right products and techniques that I could provide a full restoration.

Limestone Floor Damaged by Acid Before Restoration Wapping

Cleaning and Burnishing Acid-Damaged Limestone

My first attempt at reducing the acid stain was to apply Tile Doctor Reduxa, which is formulated to remove or significantly lighten stains caused by acidic beverages such as cola and white wine, as well as acid-based household cleaners.

I followed this by rinsing the tiles with water rinse and applying Tile Doctor Pro Clean solution, a high alkaline product that would neutralise the acid and stop it from causing any further damage. After leaving the Pro Clean to dwell on the Limestone for ten minutes, I used a handheld rotary buffer fitted with a small black scrubbing pad to remove any dirt, soap scum, and excess old sealer from the tiles and grout lines. Next, the floor was carefully rinsed with water to make sure no chemical residue remained from the cleaning products.

Although the situation was significantly improved, the stain remained visible, so the next step was to re-surface the tile using a set of diamond encrusted burnishing pads of different grades. I started with a Coarse grit diamond encrusted pad to grind away the damage layer of stone, and followed this by applying Medium, Fine and Very Fine pads to slowly hone and polish the floor, back to its original condition.

Sealing Limestone Tiles

I left the tiles to dry completely overnight before returning to the property the next day. With the acid stain removed, it was time to re-seal the floor using Tile Doctor Colour Grow, a colour- enhancing, impregnating sealer that is particularly effective at boosting the appearance of Limestone.

Limestone Floor Damaged by Acid After Restoration Wapping

The result was very satisfying for both myself and the customer. In fact, the customer even when so far as to leave the following feedback on the Tile Doctor Feedback System.

“Didi is indeed very knowledgeable and professional. I was more than a little worried by Limestone corrosion due to accidental spillage of a corrosive substance in our wet room. Didi came to sort it out for us and what to the layman looked like a catastrophe and possible new tiling operation was expertly repaired by Didi and his team. Our wet room now looks like new, much better than before in fact, and we are very grateful to Didi and also Tile Doctor for being able to head straight for the problem and sort it out so efficiently. Highly recommended!”

Source: Limestone Floor Cleaning and Restoration in in London