How to Install a Marble Top to an Existing Built in Buffet

Remove the existing buffet top. If the buffet top was recently constructed, use a utility knife to slit the rubbery sealant and remove the top. If you have an older built-in buffet, you may need to use a hammer and chisel to chip away the mortar or epoxy that holds the top in place. After the top is removed, use the utility knife to clean the remaining debris until the supporting structure has a level surface.

Measure the space for the slab of marble. Built-in buffet tops usually have three sides touching the surrounding walls. Use the tape measure to get an exact measurement of the buffet recess. Add between 1/2 to 1 inch on the side facing outwards to make a lip.

Lift the marble onto the buffet's frame. Cut the plastic sheet to fit on top of the marble slab. Tape the plastic sheet to the marble using the painter's tape.

Place the level on the marble slab. Check if the marble is completely level. Add small wood or plastic shims under the marble to achieve a level top.

Insert the tube of silicone caulk into the caulking gun. Cut a diagonal sliver 1/4-inch down from the top of the nozzle with the utility knife.

Lift the marble top from the frame. Apply a thick bead of silicone caulk around the top of the frame. If you used shims, apply caulk between the shims to fill any gaps that may show when the marble is placed down.

Pick up the marble and lay it down over the frame. Secure the marble top in place so that any space between its edges and the walls is even. Wrap a wet rag around your finger and run it over the connection where the frame meets the marble top to remove and smooth any overflow caulk.

Do not use or touch the marble top for 24 to 48, hours depending on the caulk's instructions. Rub a marble sealant into the to protect the marble surface from spills and damages.