How to Seal Sandstone Tile

What You'll Need
Soft bristled broom and dustpan
Hard floor approved vacuum cleaner
Neutral detergent
Sealant residue remover
Stone Sealant
Paint Brush
Paint Roller
Paint Tray

Sandstone tile is a popular choice of natural finish for both interior and exterior areas. These colorful stone tiles bring an organic warmth to any area, and offer a practical choice of product for easy maintenance. However, in order to get the best performance from sandstone tile, the tile surface needs to have an effective barrier in place, to protect it from possible damage that can be caused by daily wear and tear. Sealing sandstone tiles is a simple way to achieve a long-lasting, flawless finish.

Step 1 - Check For Existing Sealant Residues

Before sealing sandstone tile, it is important to ensure that it is free of residues of previous treatments. To test if the sandstone tile is already sealed, pour a small amount of water onto an inconspicuous area and leave for a few minutes. Return to the spot and wipe the area with a cloth. If a water mark remains on the floor, it is unlikely the tile has already been treated and you can move on to sealing the floor. If no water mark is observed, the floor may already have a sealant residue in place, which should be removed using a sealant remover, such as a mildly alkaline scrub with containing calcite as an abrasive, before the new sealing can commence.

Step 2 - Clean the Sandstone Tile to Seal

Before sealing a sandstone tile, the area should be free of all dirt and residues. Sweep or vacuum the floors. When debris has been lifted, use a mop and bucket and a solution of water and neutral detergent to wash the sandstone tile floor. Neutral detergents are acid free and have a pH of around seven - other detergents can cause discoloration to natural surfaces. Other sandstone surfaces can be washed with a cloth and the detergent solution.  Allow the tile to dry completely after this step. You may wish to bring in a fan to speed up the process, as no one should be allowed to use the area after cleaning and before sealing.

Step 3 - Seal Sandstone Surface 

Use a paint brush to apply a topical penetrating acrylic or urethane-based stone sealant to the borders of  the area covered by the sandstone tiles that may not be accessible when using a roller. Once all edges have been sealed with a brush, the stone sealant can be applied to the rest of the area using a clean paint roller and paint tray. Apply sealants sparingly, as many are designed to soak into the upper layers of the sandstone itself and can leave a visible residue if excessive amounts are applied. If sealing a sandstone tile floor, always begin applying stone sealant in the far corner, to avoid becoming trapped by your own efforts. Allow sealant to dry thoroughly before applying additional coats - 2 will suffice in most areas. For best results reseal sandstone tile surfaces after 2 years.