How to Seal a Marble Floor

  • 01 of 05

    Sealing Marble Floors

    Marble is a fairly porous natural stone material that readily absorbs moisture, which means that it can be stained quite easily. But protecting marble against moisture intrusion, as well as against stains, is relatively easy if you seal it when you install it, as well as every year or so thereafter. The frequency of sealing will depend on how much traffic the floor gets.

    The process for sealing a marble floor is relatively easy and should take less than an hour with each application.

    Tools and...MORE Materials You Need:

    • pH-neutral cleaner for marble
    • Marble sealer
    • Foam brush
    • Clean rag

    There are several types of stone sealer available that will work on marble floors. Some are petroleum-based and should be used only where you have adequate ventilation, as the fumes are hazardous. There are also products that are more environmentally friendly that are water-based, or use a citrus-oil base that are better choices for DIYers. 

    Look for products with silicone polymers as the main sealing agent. Some sealers add ingredients to create a "wet look," while others dry to a matt finish. Make sure to purchase the type you want. 

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  • 02 of 05

    Step 1: Cleaning

    1. Before sealing your marble floor, thoroughly clean it with a pH neutral cleaner made for marble. Do not use cleaners containing acid (including vinegar), which can etch the stone. Let the floor dry completely.
    2. Test a small amount of the marble sealer in an inconspicuous area to make sure the sealant will not discolor the stone. Allow the sealer in the test area to dry thoroughly, then compare its appearance to the other tiles. The only difference should be that the sealed surface is slightly...MORE glossier than the others. If the sealer creates dramatic color differences, you should try another type of sealer.
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  • 03 of 05

    Step 2: Apply Sealer

    Apply the sealer to each tile individually, using a foam brush or soft cloth dipped in the sealer. The goal is to create a very thin layer that evaporates in a matter of minutes. Do not allow the sealer to puddle. If bubbles do form, smooth them out with the front edge of the brush.

    Follow the sealer label instructions regarding the method of application—some prefer foam brush application, others suggest using a cloth. 

    Let the sealer dry completely—this usually takes two to four hours.

    Tip: You...MORE can't walk on the sealed tiles until they are completely dry, so start at one wall and work your way back toward an entry so you don't box yourself in.

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  • 04 of 05

    Step 3: Seal the Grout Joints

    Seal the grout joints as you complete each small section of tiles. Dip the foam brush lightly into the sealer, then run the thin edge of the brush along each of the grout lines. Use the broad edge of the brush to wipe up any excess.

    Let the sealer dry completely. 

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  • 05 of 05

    Step 4: Repeat Application

    When the sealer is completely dry, repeat the application to the marble and the grout joints. You can walk on the floor within a few hours, but wait until the sealer has fully cured—48 to 72 hours—before resuming normal cleaning of the floor. You should also keep any potentially staining materials (stain agents) out of the area until the sealer has fully cured.