Marble countertops can be heavy and brittle, so they come with certain size limitations in width and length for them to hold and remain stable. Prefabricated marble countertops have standard sizes, and they vary slightly depending on the manufacturer. Custom marble countertops have more options in size and shape, but they are more expensive and harder to install.
Prefabricated marble countertops
Prefabricated marble countertops are supported with a base and have overhangs on both sides. The length span in between two separate bases can be a minimum of 24 inches to a maximum of 36 inches as long as the marble is supported on both sides. The overhang that is not supported by the legs should not exceed six inches. Most prefabricated marble countertops are one-half or three-fourths of an inch thick. A prefabricated marble countertop should not be too thin because marble is brittle and can crack easily. It cannot be too thick either because marble is heavy and can collapse. The width of the marble should be supported by two separate bases as foundation. The bases should be thicker for a thicker slab of marble. Some prefabricated marble countertops can be as thick as one and one-half inches. The thicker the marble slab is, the wider and stronger the support should be. Prefabricated marble countertops with support come in standard sizes. The depths of prefabricated countertops are 26 inches for kitchen countertops and 22 inches for vanity countertops.
Customized marble countertops
Custom marble countertops can vary in length span. They can be installed in existing fixtures such as kitchens or bars. Most manufacturers who customize marble countertops can install them on an existing base like a closet or a kitchen island. Marble countertops can be customized into any shape and design as long as the standard rules for top and base proportions are followed. The sink and faucet holes for kitchen countertops can be drilled on as long as the dimensions are provided. When getting a customized marble countertop, make sure it is made of a thicker marble slab. You have a choice between a slab that is three-fourths of an inch-thick to a slab that is one and a half inch-thick. Thicker marble slabs can survive shipping and installation better than thinner ones, but they must still be supported as well.
Working with seams
The seams are the joints where the two pieces of marble slabs meet. No two slabs are the same and they make natural, if inconsistent, patterns. This pattern inconsistency is the advantage of marble countertops and all stone countertops because it gives them a more natural look. Marble countertop manufacturers often use an epoxy to seal the seams and make them less noticeable. Some manufacturers offer to match the patterns and coloring of marble slabs to make the seams almost invisible.