Resealing Natural Stone

If you have stone floors or countertops in your home, you are most likely familiar with their unique qualities and needs. Natural products are porous, meaning they can absorb liquids and, as a result, become stained by normal use. Because of this, materials such as marble, limestone, soapstone, travertine, slate or granite, should be periodically sealed. Sealing makes the stone less absorbent and therefore prevents staining, but there are some that do not require it. Be sure you know your type of stone before embarking on an unnecessary, and possibly damaging, process. Below is a basic overview of sealing or resealing your natural stone surfaces.

When to Seal Your Stone

Although sources disagree about when to seal stone, there is general agreement that it is a necessary step. Sealing horizontal surfaces, such as floors and counters, is integral. In the case of vertical surfaces, such as shower walls or backsplashes, some experts feel the process could be skipped.

To ensure protection, stone tiles should be sealed twice. The first sealing should occur once the stone is in place, but prior to grouting. This will protect the tiles from grout sticking to the surface. Everything should be sealed again once the grout is cured. After the initial sealing, the stone will be protected for about a year, depending on the type that was used. Consider resealing around the one-year mark to protect your investment.

You can test if it’s time to reseal your stone by pouring a small puddle of water and then observing the rate at which it absorbs. If the water leaves a mark in less than 10 minutes, it’s time!

What to Use to Seal Stone

There are two basic types of sealants that homeowners can use on stone surfaces. Water based sealants, good for use on marble, limestone, soapstone or travertine, are easy to apply and don’t emit many VOCs as they dry. The smell is minimal and so is the cost, but the results are not that long lasting. Solvent based sealants, recommended for use on granite surfaces, are more costly, emit more VOCs and also more odor. The advantage is that they penetrate better and have a longer lasting effect. Be sure to consult the manufacturer’s instructions and do a spot test in an inconspicuous place if you are unsure.

How to Seal or Reseal Stone

The basic steps to sealing stone are as follows:

First clean your stone, using a ph neutral cleaner designed for use on natural products. Using anything with acid, even a mild solution of household vinegar and water, can damage them. When in doubt, don’t! Purchase a cleaner specified for use on stone. Spray or apply the cleaner, allow it to sit for a few minutes, then gently rub with a sponge or cloth and wipe away. Allow the area to dry thoroughly.
Next, apply the sealant recommended for your surface with a clean chip brush or a pad. Work in sections no bigger than about four to six feet, making sure to sufficiently cover stone and grout surface.
After the sealant has soaked in for about 5-10 minutes, gently apply more sealant with a rag to rewet the surface and eliminate streaks. This step is crucial but often skipped.

Use a soft cloth to wipe the surface after 1-2 minutes.

Repeat the steps on the next section until finished. Finally, allow the entire area to dry completely and cure for 24-48 hours. *If you are concerned about foot traffic, seal half the floor at a time, allowing enough space for walking and adequate drying time. Once cured, repeat the process on the other half.

When to Call a Professional

While sealing stone is not difficult, if your surfaces have been neglected, you may want to consider professional help. Stains, cracks, etching or other damage may require advice or assistance. If you find the whole process overwhelming and you’d like to speak to someone who knows all about stone, reach out to the helpful staff at DeGraaf Interiors. They can recommend products, processes, or professionals who can help you get- and keep- your stone looking its best.