Marble and limestone will lose their shine over time in areas which are walked on. The speed with which this happens depends upon how many 'shoes' are passing over the floor each day and whether a good maintenance programme has been used which can delay this process. Whatever happens however the floor will ultimately become dull. So what at this point can be done to restore the floor back to new?

There are really four alternatives for restoring the shine to your floors.

1. Re-grinding the crystals so as to remove the scratches and polish them. This is done by diamond grinding. Using finer and finer grades of diamonds to bring about the effect. This should be done if you have deeper scratches or you want the most natural looking floor and a high shine. The downside of this is that it can be very expensive in equipment and man hours but it does give the best finish.

2. Powder polishing the stone. In this aluminium or tin oxides are used as abrasive powders for the re-polishing of the crystals. Added to the mix is oxalic acid which acts as a cleaning agent. The acid reacts with the calcium carbonate to form calcium oxalate crystals which are easier to polish and produce more shine than the original carbonate. This reaction only occurs in the first outer layer of surface crystals; about one thousand of a millimetre! The powders have to be washed off and wet vacuumed up afterwards before the final buffing. The downside of this is that it is messy and time consuming in man hours.

3. Re-crystallization of the stone. In this method Fluorosilicate acid is sprayed over the floor and a heavy, slow buffing machine with a steel wool pad is used. This is required as pressure and heat are required to transform the calcium carbonate crystal to calcium fluoride crystals. It can however be used on only those areas that require it and it is relatively quick. The result is a more hard wearing surface and a very brilliant shine. In many circumstances this is the operation of choice as it is the quickest and cheapest method and results in a surface which will retain its shine for longer.

4. The quick, cheap and easy fix! This method involves putting down a surface covering over the stone to make it shiny. It can be emulsion polish, wax, urethane or an acrylic covering. It looks okay for a little while but eventually it will require re-doing. When that happens the old covering has to be stripped away using very caustic strippers which will damage the stone. Also the stone will not look natural, be more prone to damage and can undergo quite dramatic colour changes. This one is not to be recommended. If you contemplate using this method then you should not have had the stone installed initially. It is a practice advocated by those cleaning companies who do not know how to maintain natural stone correctly.

David Andrew Smith is the co-owner of a cleaning services company which provides amongst many other services a natural stone cleaning and maintenance programme especially within the London area but all over the UK.