Experts in stone floor cleaning

Natural stone floors can be exceedingly beautiful whether they are marble, granite, slate, limestone, travertine, onyx, basalt or sandstone however they will all need to be cleaned and maintained correctly. There are many ways to clean stone floors but before you attempt any cleaning you should be aware of the composition of different stone types, this will determine which chemicals you can and cannot use. Tip: Always find out exactly what stone type you have before cleaning!

There are three basic classifications of stone types, Igneous Rocks, Sedimentary Rocks and Metamorphic Rocks, the identification of each classification is as follows;

IGNEOUS
Igneous rocks are formed from the solidification of magma deep in the earth, they are 45-66% silica (Quartz). The remaining minerals are mostly feldspar, mica and iron ores. The most abundant igneous rock found on earth is Granite. Igneous rocks exhibit a crystalline form with grain size ranging from very small to several inches. The smaller crystal granites are formed when the cooling process is very rapid and the large crystals when the cooling process is slower. This all takes place deep in the earth before the magma reaches the surface, if it does reach the surface then it is termed ‘lava’. Hardness ranges from 6 & higher on the Mohs scale of hardness. Igneous rock will generally not react to acids. However Hydrofluoric Acid will affect the surface. Many brick and grout residue cleaners will contain Hydrofluoric Acid so make sure to check cleaning chemical MSDS before using on all stone floors. Many Anti Slip acid etching chemicals also contain Hydrofluoric Acid so be aware before anyone uses these without training or advising on appearance change.

SEDIMENTARY
Sedimentary rocks are produced from erosion of other rocks as well as compression and underground water erosion (Lithofication). The Sedimentary group is split into two types; Limestone & Sandstone. Limestone is formed in the shallow waters of the sea shelf. It consists of calcite but may be mixed with other minerals depending on how clear the water was when it was formed. Limestone will often contain fossils and shell fragments because it was formed in the sea. Sandstone are primarily quartz minerals loosely cemented together with calcite, iron oxides and/or mud. Sandstone can be easily identified by its distinct sand like appearance.

METAMORPHIC
Metamorphic rock (Marble & Slate) is limestone that has been exposed to high temperatures and high pressures over a long period of time. This change is known as metamorphoses and hence the name metamorphic, the change causes the minerals to go through a molten phase which is often the reason for marbles to have distinct swirls or bands. Most marbles have distinctive veins, however there are exceptions to this rule so do not rely on this parameter alone. Acidic product will react and affect the surface.

UNDERSTANDING pH
The understanding of cleaning chemistry is an essential part for all involved within the cleaning and restoration business and will prevent many problems occurring. Chemistry is the science of chemical properties, compositions, reactions and the uses of a substance. For example when you pour an acidic chemical on a piece of marble, the acid attacks the calcium in the marble or when you mix a detergent in water you are creating a solution that has different properties than individual chemicals.

pH is used to express the acidity or alkalinity of a chemical liquid, the scale only applies to water based chemicals. The pH scale ranges from 1 – 14. A pH of 1 – 7 is considered an acid, a chemical with a pH of 2 will be a stronger acid that one with a pH of 6. A pH of more than 7 is considered to be alkaline, pH14 is the strongest alkaline. A pH of 7 is neutral, neither acid nor alkaline. A good neutral detergent of pH 7 is considered safe for your stone flooring.

Determining the soilage type is vitally important, these fall into two categories 1) Water Loving and 2) Oil Loving. The use of a general stone soap is a good place to start for both types. You should utilise the use of a rotary floor machine to scrub the floor with a soft brush or a red pad and the correct dilution of stone soap and water (detergent & water). You will then need to remove the dirt that is suspended within the water slurry with the use of a wet vacuum. A light rinse using water and a microfibre mop afterwards will finish the process nicely. If the floor is of a larger size then the use of a scrubber drier can save you a lot of time, if your floor is a riven textured surface the scrubber drier should have the brush attachment fitted and if it is a smooth honed or polished surface a red pad will be more effective. If your floor is sealed you can use a detergent that is more alkaline around the pH10 scale that will provide a deeper clean.

How to clean a stone floor…

WHAT HAPPENS IF THIS IS NOT ENOUGH?
If your marble is worn it may be required to polish the surface using diamond polishing technology, this comes in varying levels depending on how competent you are at stone floor restoration. There are numerous suppliers of diamond impregnated pads that will do a reasonable polishing job, but if you are looking for a professional finish the use of resin based diamonds and stone grinding machinery will give a deeper lustre and flatter appearance.

It is important that if you go through the restoration and polishing process that you seal your stone floor afterwards. The two types of sealants are topical and impregnating, the most effective sealants for stone are impregnating, this means that it penetrates into the stone surface and protects the stone from staining.

If you require any further information, advice or would like to book a FREE site survey please contact us – 01564 742 095