The Definitive Guide to Sealing and Protecting your Stone

Beyond Stone Solutions - Ultimate Guide to Sealing Stone - Granite Countertops


All stone is porous, some more than others. For most stone—especially very porous stones like hone-finished limestone or certain granites—the application of a quality impregnating sealer is highly recommended.

The application of an impregnating sealer to highly-polished marble and travertine, or polished high-density granites, may not be necessary—but when in doubt, consider this: it doesn’t hurt to have it sealed. If it turns out that sealing the stone does, in fact, prevent some staining, you’ve saved yourself the cost of a stain removal service.



For some stones that are more porous than others, one application of impregnator/sealer may not be enough. But how will you know?

On granites that need sealing, at least two applications are recommended. Very porous granites, sandstone, quartzite, etc., may require three or more applications. When sealer can no longer be absorbed by the stone, the stone is adequately sealed.



There is no absolute rule of thumb when it comes to the durability of any sealer. Generally speaking, most quality impregnating sealers interior will last 2-5 years or more. Environment plays a big role. Stones exposed to intense heat or direct sunlight will probably need to be re-sealed more often.



To find out if your stone is perfectly sealed, pour some water on it and wait for approximately half an hour, then wipe it dry. If the surface of the stone did not darken, it means that the stone is still perfectly sealed. Be sure to test various areas, especially those areas that get more use and abuse.


Beyond Stone Solutions - Ultimate Guide to Sealing - Kitchen Stone Floors 



Contrary to what your perception may be when you hear the word sealer, most sealers for stone are below-surface products and will not alter in any way, shape or form the

original finish produced by the factory. They will not offer protection to the surface of the stone, either. They will only go inside the stone by being absorbed by it (assuming that the stone is porous enough to allow this to happen) and will clog its pores, thus reducing its natural absorbency rate. This will help prevent possible accidental spills of staining agents from being absorbed by the stone. On the other hand, granite is more porous than marble and may stain if not protected with a good-quality, impregnator-type stone sealer. Stay away from topical sealer, waxes, and coatings. Some “granites” are so porous that no sealer will do a satisfactory job sealing them 100% for an extended amount of time.

Sealers for stones, which are below-surface, penetrating-type sealers—better referred to as impregnators—are designed to do one thing and one thing only: clog the pores of the stone to inhibit staining agents from being absorbed by it. In some instances, “weird” problems that may appear to be etching on “granite” counter tops turn out to be created by sealer residue that has left a haze on the stone or reacted with substances that had spilled on it. In these cases, once the sealer is professionally removed, everything is fine.

Note: Sometimes, marks of corrosion (etch marks) that an acidic substance leaves behind may look like water stains or rings, but they are neither stains, nor were they generated by water. The deriving (surface) damage has no relation whatsoever with the porosity of the stone (which determines its absorbency), but is exclusively related to its chemical makeup. Special topical treatments are becoming available for acid-sensitive stones that are designed to offer some protection from acids, while still allowing the stone to breathe. Ask us for more information on this.


Beyond Stone Solutions - Ultimate Guide to Sealing - Living Room Stone Floors



While impregnating sealers will not alter the appearance of your stone, a color-enhancing (impregnating) sealer will protect the stone while bringing out its color, giving it a wet (i.e. darker, not glossy) look. It will at the same time provide good protection from water- based staining. Color enhancing sealers are typically used on tumbled marble, low-honed limestone and travertine, honed (black) granite, etc.



Cementitious grout is porous and will absorb liquids, which can potentially stain and result in the growth of bacteria. Sealing your grout provides a protective barrier that not only preserves it from stains, it makes routine cleaning and maintenance easier.

Grout can be sealed with a clear sealer or it can be color sealed. Color sealing has the added advantage that it allows you to completely change the color of your grout, whether it is just for a new look or to cover up stained and discolored grout.


SEALING: DIY or Call in a Pro?

Is sealing a job for the homeowner, or should you hire a qualified professional to do it for you? Consider the following pros and cons.

You save on labor costs by doing it yourself. However, consider the magnitude of the job and how comfortable you are with a DIY project. Are you prepared to get on your hands and knees to seal a floor? Are you willing to apply multiple applications if needed?

Has the floor or surface been thoroughly and completely cleaned? If not, you take the chance of sealing in dirt and debris. Also, keep in mind that sealer not completely removed from the surface of stone may cause problems, including a haze on the stone that may develop as the sealer dries completely. Once it is dried on the surface, sealer can be very difficult to remove.

Different sealers perform differently in different environments and on different stones. Hiring a pro to do the job may end up saving you in the end. A pro will know which is the best sealer for the job and will use equipment and techniques that allow them to get the job done efficiently.

Thanks for looking at our guide, if you have any questions feel free to contact us.