A stone fireplace adds a classic and period look to any home but like the stone floors we deal with its only a matter of time before the appearance degrades, however not from foot traffic but from soot. This process happens so gradually it goes without being noticed until one day you realise it really does need a good clean and the dirtier it gets, the harder it is to clean.

I recently visited a customer living in the historic city of Oxford who had never once cleaned their black Limestone fireplace. One day, they decided to finally clean it but found that it would take a lot more than just a light scrub with some soapy water!

As you can see from the photograph below, the Limestone was extremely dirty, dusty and stained. Upon examining the situation, I decided that the best way to restore the stone to its original condition would be to use a polishing process known as burnishing. Keen to see the natural beauty of the Limestone again, the customer was more than happy to book in the job.

Cleaning and Burnishing a Limestone Fireplace

As I would be focusing solely on the Fireplace, it was necessary for me to start by protecting the surrounding area with tape. I then began the process of burnishing, starting with a 200-grit diamond encrusted handheld burnishing block. I sprayed a small amount of water onto the fireplace to act as a lubricant and rubbed the diamond encrusted block onto the stone.

This coarse grit pad helps to grind away the thick layers of dirt on the surface of the Limestone and starts to gradually polish the surface beneath. I completed the burnishing working in small sections at a time, rinsing with fresh water and wiping excess off regularly as I progressed.

After finishing with the 200-grit block I then repeated the process using a 400-grit block. This block possesses a finer grit and really helped to achieve a high-quality polished effect.
While the Limestone was drying, I treated the black fire grate with the correct grate paste (or polish) which cleaned it and recoloured it.

To complete the cleaning process, I paid attention to the black tiles on the floor. These were cleaned using Tile Doctor Pro-Clean diluted with water, and scrubbed into the stone and grout using a small specialised brush. Finally, I rinsed the area with fresh water and dried it with a towel.

Sealing a Limestone Fireplace

I then had to leave the fireplace to dry for about an hour so it would be ready to seal. To seal the Limestone, I used Tile Doctor Ultra-Seal, which offers the natural looking finish that the customer wanted. This sealer is formulated to provide maximum protection against stains and dirt, and is suitable for use on all types of natural stone.

The customer has decided that although this will no longer be used as a working fireplace it, will certainly give the room a focal point – so she was very happy to have it back to looking its best!