What Is Used for Mortar Cultured Marble?

Thinset Mortar

• While thinset mortar is generally reserved for actual marble, you can use it on cultured marble as well, so long as you purchase a type that is rated for use with man-made products. A white thinset is best, as a dark thinset will alter the color of your cultured marble. The underlying mortar may not be visible to the eye, but the color of the mortar will tint the overall hue of the cultured marble panels.

Skim Coating

• If you are using a thinset mortar it is important to skim coat the back of the cultured marble sheet or panel before it is installed onto the troweled section of mortar on the wall. Because the notched trowel leaves behind ridges which are then flattened somewhat when the sheet is installed, those ridges will sometimes show through the panel as the mortar dries. It is important to cover the entire sheet in a thin layer known as a skim coat so coverage is complete and nothing bleeds through.

Troweled-on Adhesives

• One method for installing cultured marble is with all-purpose adhesives, but the same rules apply as with thinset. Not only do you need to comb the adhesive onto the installation surface with a notched trowel, but you also need to skim coat the back of the cultured marble piece so that the ridges of adhesive don’t show through the surface as the adhesive dries in place.

Clear Adhesives

• Clear adhesives and mortars are preferred for cultured marble installation, such as with epoxy mortars and silicone adhesives. Because they are clear there are no colors or hues that can potentially bleed through the surface of the marble. This means you can install the cultured marble without worrying about skim coating the panels or sheets before they are installed.