Limestone is a sedimentary rock formed from calcareous remains of plants and animals and often contains the fossils of sea creatures. It is natural Calcium Carbonate (CaCO3). It has a smooth granular surface and varies in hardness. Some dense limestone can be polished but will never be as shiny as marble or granite. Limestone floors with a honed finish (not shiny) are quite popular. The colour tones are typically neutral – beige, cream, light brown. Many older buildings have durable limestone flooring. This is a chalky porous type of limestone.
, in spite of the drawbacks limestone is still extensively used for internal and external flooring and cladding. The subtle neutral tones and colours provide a timeless focal point around which home furnishings can be updated as fashions change. Limestone also has heat conducting properties which many more durable flooring materials do not have. For this reason, it is chosen for use with under-floor heating systems.
Limestone is easily etched by acids, including soft drinks, and it will absorb oil and other liquids more easily than marble. Limestone statues and building surfaces can suffer severe damage due to acid rain in areas of air pollution. Acid-based cleaning chemicals can also etch limestone. It is important to use only Neutral Ph. cleaner such as EQUALIZER to clean your limestone flooring or countertop.
Limestone should be sealed with a penetrating sealer to prevent staining and reduce soiling. We recommend COTERSEAL. However, whilst this type of sealer will prevent deep staining and inhibit dirt build-up, it will not prevent etches from acidic substances and scratches caused by grit on the soles of shoes.
For added protection, a topical sealer or finishing sealer can be applied. We recommend FOCUS This type of sealer sits on the surface of the limestone and creates a barrier against liquids and grit. Topical sealers are generally available in matt, satin, and gloss finishes. Topical sealers are more suitable for honed limestone where they are able to ‘key’ onto the surface. They are not suitable for polished limestone. Applying a topical sealer will reduce the work required in maintaining the floor as dirt and dust sits on the surface and can easily be wiped away with a wet cloth. However, it must be stressed that the sealer itself will dull and wear over time, and eventually the floor will need to be stripped and re-sealed. To extend the life of the sealer it is important to keep the floor free of grit and dust and also to use only mild cleaning detergents. Harsh and abrasive cleaners will wear the sealer away in a short time.
Polished limestone floors lose their shine if proper maintenance procedures are not adhered to. The use of acidic cleaning detergents will result in a dull, almost matt, appearance to the floor. Each time the acidic cleaner comes in contact with the calcium it causes a reaction that is effectively eating the top layer of the limestone. The only way to restore the shine will be to grind the surface using purpose-made polishing equipment and specialized chemicals and stone waxes. This work should only be carried out by trained stone care and maintenance professionals.
As the old saying goes ‘prevention is better than cure. This is so true when it comes to looking after limestone floors and countertops, and indeed for looking after most types of natural stone. Limestone is a relatively soft type of natural stone as measured on ‘The Moh’s Scale of Mineral Hardness. It can be easily scratched by harder materials such as grit and metal. It is also quite porous and absorbs moisture and liquids which may leave a stain. Composed primarily of calcium it is quite susceptible to damage from acidic substances such as fruit juices and wine. Even leaving a wine glass overnight on your countertop or floor may result in the appearance of an unsightly circular etch that can be hard to remove.