Question: Why Does Natural Stone Need A Sealant?

I’m thinking about installing natural stone in my home, but I keep hearing about having to re-apply sealants every so often. I’m worried that this is going to be expensive and time-consuming. Why does natural stone need a sealant, and what are the facts about upkeep?

In short, all natural stone surfaces need to be sealed periodically. This is because stone is naturally a porous material and can absorb bacteria, food particles, and liquids that we use throughout our home. Not sealing a stone countertop or floor tiles — which get the heaviest traffic and are the most susceptible to wear and tear — leaves the surface vulnerable to absorbing foreign substances, which can weaken the stone and potentially lead to the growth of bacteria.

That being said, not all stones are created equal. Marble, onyx, and limestone are some of the most desirable stones on the market, but all three are very susceptible to staining, scratches and, in particular, to acid etching. This means that if an acidic material touches the surface of the stone, it will leave a dull mark that may be difficult to remove. Because these stones have a high porosity, it’s important to seal them about every six months and clean them with solutions specially designed for natural stone. This upkeep is essential to making sure your floors and countertops remain beautiful and functional for decades to come.

In contrast, granite and quartz are much less porous and don’t need to be sealed as frequently — about once per year will be enough to seal up any exposed pits and fissures that can harbor bacteria. In addition, granite and quartz don’t require special cleaners, just some soap and water on a soft cloth is all you need to mop up any messes that occur.

The good news is that sealing your stone surface won’t cost a fortune. You can expect to pay between $40-$60 on a conatiner of sealant, depending on the formula and manufacturer. You can also seal the stone yourself in just a few easy steps. While it’s important to follow the instructions that come with the sealer you buy, in general you’ll want to start by thoroughly cleaning and drying the countertop. Then, spray the sealer onto a soft cloth and begin to work it into the stone in small sections. Next, allow the sealant to dry for 24 hours, then apply a second coat working just as before. After this second coat dries, you may then choose to apply a topical sealer, which adds shine to the stone and as well as added protection from water, acids, and oils.

Finally, keep in mind that no sealer will do a perfect job at preventing your stone from being damaged. It’s best to get in the habit of using coasters under drinking glasses, and don’t allow liquids to linger on your stone floor or countertop after a spill. If you remember to wipe up messes right away, you can stop any potential stains dead in their tracks!