Cultured marble is a very hard man-made material commonly used for bathroom sinks and counter or vanity tops. A cultured marble top is made from resin, marble dust, pigment and a catalyst. The product can be set in a mold and finished with a marble-like surface; it comes in a variety of styles and colors. When installing a cultured marble top, it may be necessary to cut it to size, which can create a challenge because the hard surface of your marble top can splinter, chip and scratch easily during cutting.

1
Measure the cultured marble top in comparison with your proposed installation area, and mark where you need to make a cut. Mark the unfinished underside of the top, using a pencil.

2
The surface can be easily scratched if not protected during cutting. Use a blanket to cover your work bench to protect the top, before cutting.

3
Position the marble top face down in a position that gives easy access to the pencil-marked cutting area. Attach and secure the marble top to your work bench using vice grips or clamps. Double check that the top is secure and won't slip, to avoid having the marble top slip while you are cutting. If the top slips, this will result in a bad cut and you may have to replace the top.

4
Use a rotary saw and a new or sharp masonry blade to cut along the pencil lines. Guide the saw gently along the cut line, rather than using pressure or force, to avoid causing splinters or chipping. As you near the end of the cut at the edge, slow down and proceed with caution, without force, to get a clean end cut on the marble top.

5
Use 60-grit sandpaper, or a lower grit, to sand and smooth any ragged edges on the cut. Use care not to scratch the finished side of the cultured marble top with the sandpaper.