How to Finish Concrete Floors to Look Like Marble

Do an image search to find a photo of the type of marble you'd like to reproduce or purchase a sample from a home-improvement center or tile store. If this is your first foray into faux finishing a concrete floor, choose a marble that is fairly simple to replicate with no more than four different colors.

Sweep and wash concrete floors with a mop or cellulose sponge using a degreaser (such as trisodium phosphate) to remove dirt, oil, stains, and any existing coatings or sealers. When handling a somewhat toxic product like TSP, be sure to wear clothing that covers your arms and legs, in addition to gloves, safety glasses, and a respiratory mask. Be sure there is adequate ventilation where you're working.

Because TSP can leave a residue, rinse the floors with clean water and allow them to dry completely.

Using a self-priming paint formulated specifically for concrete or masonry, apply the marble base color (or colors) with a large paintbrush. The number of colors you'll use is determined by the marble sample.

In small plastic containers or glass jars, make latex glazes with a mixture of acrylic paint and glaze medium in the colors found in the marble sample.

With a paintbrush or sponge, apply the accent hues randomly yet in the same general direction to achieve an authentic marbling effect. Blend edges well to eliminate hard lines.

Create depth, texture, and movement by adding many layers of glaze, splattering small amounts of water randomly to mimic real marble's mottled look.

Using a fine artist brush, draw a combination of thin and thicker veins in the same general direction as the layers you created. Be sure veins don't run in a distinct pattern and aren't repetitive; they should appear jagged, not wavy, and have both soft and hard edges.

While the veins are still wet, lightly sweep a flat, dry paintbrush back and forth across the lines to achieve a wispy effect.

To create even more of an allusion of depth, after veins are dry, roll or brush on a thin layer of water-based polyurethane (gloss) and let it dry. Repeat steps 7 and 8. Let it dry.

With a paint roller, apply four protective topcoats of high-gloss polyurethane as a protective finish, allowing each layer to dry before applying the next one.

It's super important that the painted concrete floors be bone dry before using them. Patience is a virtue since walking on the floors before they are set will cause damage to your beautifully painted floors.