Both polishing compounds and diamond abrasive discs will successfully grind marble down – removing scratches that occur over time and restoring the original polish and shine. If marble has uneven tiles, deep cracks or holes, or hairline fractures, you should have a professional examine the marble before diving in to do it yourself. If the damage is too great, you could inadvertently make it worse and need to hire a pro anyway.

Clean the Surface Before sanding or grinding any marble surface, you want to clean the area thoroughly. Any dirt or residue left on the marble can cause damage as you sand. If that happens you’ll have to clean it and sand again. Do not use any cleaner labeled as a “stripper.” These cleaners soften and degrade marble so during the grinding process you will lose more stone than you intend.

Remove Lippage The point where tiles meet at the grout line is generally not level even though it may look it. If you run your hand over the grout line you will notice a definite dip. Sometimes this can be very uneven with a tile being a few millimeters higher than the adjacent tile – this is known as lippage. The first stage in the diamond grinding process is to remove any lippage so that the floor is completely even and flat at the grout lines.

Don’t forget our previous blog: Looking into a Concrete Floor Grinder?

Repair Cracks Before you sand or grind a marble surface, fill in any small cracks. Grinding cracks will cause the edges to chip, creating holes and more things to repair. In addition, polishing grit or marble dust will fill the crack and redistribute over the surface during the next step, scratching rather than polishing the surface.

Diamond Polishing Once you have completed the above steps you can get to grinding. Diamond grinding can be done to a very fine grade until a polished finish is achieved. These final grades reduce scratches, which are not even visible to the human eye, allowing the natural crystals on the surface to reflect light more effectively. This is an extremely skilled task, which requires patience and experience.

Don’t go all in right away. Take one pass and examine the finish to be sure it is coming out the way you intend. If individual scratches are not removed effectively in the early stages then the finer grades will only serve to magnify them.