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Hidden underneath a lot of grime and staining in the basement of a building of special interest (Grade II-listed) in Plymouth is a fantastic Limestone tiled floor that was originally sourced from a local quarry near the city.

The floor had been hidden under a covering at some point in its history, but for at least the last decade it had been used to house dogs. As far as the new owner of the building could tell, the floor had never once been cleaned! To worsen the situation, the floor had also suffered from damp during winters and periods of heavy rain.

The customer got in touch because the suggested solution that was accepted by the council was to install an expensive floating floor on top of the limestone and hide this lovely feature. I produced a report on the floor about how the design of the traditional floors worked, plus my findings and recommendations which was passed to the council. The recommendations to re-grout in a natural lime mortar, mill the stones to lift any grime and improve any mild undulation and lippage to help with any pooling issues and to seal the floor in a breathable sealer were endorsed.

Plymouth Limestone Floor Plymouth Before Restoration

Milling a Stained Limestone Tiled Floor

The first job was to rake out all the existing grout, an inappropriate patchwork of cement and lime which had been completely scuffed away in parts and was contributing to the damp issues by preventing the floor from working how it was designed to (moisture permeates evenly through the lime-based grout and evaporates into the house due to the heat of the people living there). The grout, or pointing, was then replaced with lime mixed with a ratio of 1:3 with sand which is what would have been used originally, allowing the floor to ‘breathe’.

Following this, a process called milling was used which uses diamond-impregnated discs to cut the surface of the stone back and strip the stone, opening the pores to remove any stains as well as flatten any stones out where necessary.

Sealing a Limestone Tiled Floor

After successfully removing the grime and stains on the surface of the floor, it was necessary to seal the stone to protect it against ingrained muck in the future.

To do this, I used Tile Doctor Colour Grow, which is our colour-enhancing, breathable sealer which prevents moisture from becoming trapped. Additionally Colour Grow is an impregnating sealer that penetrates and fills the pores of the stone to block dirt and stains becoming trapper there, it also leaves an aesthetically pleasing natural look finish which really suited the character of this Limestone tiled floor.

Plymouth Limestone Floor Plymouth After Restoration

It took some work and once done the floor looked fantastic, certainly the new property owner seemed to think so – he was exceptionally happy to have this fantastic feature back to looking its absolute best and left the following feedback.

“Stuart completed the restoration of a stone floor within a Grade II listed building. He completed milling and polishing of the 200 year old stones over around 50m2. The outcome of the work was amazing; the floor was transformed from a dull grey colour to a finish like marble. Great service provided and looking forward to working with you on again on the next project.”
Mr J. Yorke, Plymouth
 
 
Source: Limestone Tile Cleaning and Restoration in Devon

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: Tile, Stone and Grout Cleaning and Restoration in London

We often come across tiled floors that have simply never been maintained after their original installation. This inevitably leads to problems: over time, the sealer starts to wear away, particularly in high traffic areas, allowing dirt and staining to become easily ingrained in the stone and grout. The longer this is left unaddressed, the harder it becomes to clean the tiles.

An excellent case in point are this cream coloured Polished Limestone tiled floor installed in the downstairs WC and upstairs bathroom of a property in the prosperous Merchiston area of Edinburgh. The floor were already laid when the customer bought the house 10 years ago, and as far as they know, it has never experienced professional maintenance.

Limestone downstairs toilet Floor Merchiston before

The result of this is quite clear: just looking at the photos below you can see how dull and unimpressive the tiles looked before I was called in to restore them to their best possible condition. The customer was particularly unhappy with how easily the floor became stained and patchy where the sealer had failed in certain areas of the floor.

Limestone Bathroom Floor Merchiston before

Cleaning and Burnishing Limestone Floor Tiles

To clean the Limestone tiles, I used Tile Doctor’s system of four diamond encrusted burnishing pads, which range from Coarse to Very Fine. The abrasive Coarse grit pad are applied to cut back through the stone to remove stains, while the Fine and Very and Fine pads are applied to achieve a high quality polished shine.

The pads are fitted to a rotary machine in sequence from coarse to fine and lubricated with a small quantity of water which is sprayed onto the surface. The resultant slurry is rinsed off with more water and extracted using a wet vacuum.

The downstairs WC was approached using much the same method except the space was tighter so we had to use smaller six-inch burnishing pads fitted to a handheld buffer.

After completing the burnishing process, I scrubbed the grout with a narrow brush and a strong dilution of Tile Doctor Pro Clean, which is a high performance alkaline cleaner, to remove any dirt and stains.

Last step before leaving was to rinse both floors with water to remove any trace of cleaning solution. The wet vacuum was then used to remove as much water and moisture from the tiles as possible.

Limestone Bathroom Floor Merchiston during

Sealing a Limestone Tiled Bathroom Floor

I left the floor to fully dry out overnight before returning the next morning to re-seal the stone which would protect it from future staining.

My choice of sealer was Tile Doctor Colour Grow, which is the ideal sealer for sealing Limestone. As an impregnating sealer, it penetrates deep into the pores of the stone to fill them and prevent dirt from becoming ingrained there. It also subtly enhances the natural shades in the stone.

Limestone downstairs toilet Floor Merchiston after

The customer was delighted with the job as both floors were completely transformed. It’s sometimes hard to believe how long some tiles go without proper maintenance, but it’s equally amazing just how quickly they can be rejuvenated with the right products and methods!

Limestone Bathroom Floor Merchiston after
 
 
Source: Limestone Cleaning and Maintenance Service in Edinburgh