Everything (and then some) You Ever Wanted to Know About Sealing Your Natural Stone

Are you a little confused about whether or not to seal your natural stone? You’ve done your homework and researched the topic on the web only to find that there are opposing opinions on the topic. Most experts recommend sealing all stone while others emphatically state that not all natural stone needs to be sealed.

STONE ABSORBENCY TEST

To get a general idea of how absorbent the stone is, place several drops of water on the surface of the stone and time how long it takes for the water to completely disappear. If the water disappears in under one minute, consider the stone very porous.

If it takes up to 3-4 minutes, consider it porous. If it takes more than 3-4 minutes, consider it slightly porous. This simple test will also give a good indication of the quantity of sealer needed to protect the entire area.

SO WHAT IS THE ANSWER?

Let’s make it simple. To be safe, let me say that for the most part, all stone surfaces should be sealed for maximum protection. The worst case when you are dealing with a stone that is not very porous is that the stone will absorb very little sealer to achieve maximized protection. Don’t look the cost of the sealer as a waste of money though. Consider it added peace of mind.

(Tip: see the about testing absorbency first. If your stone is not very absorbent, buy only a very small bottle of sealer.)

Caveats

New Countertops? Some granite countertops are pre-sealed. Ask your fabricator or perform the Stone Absorbency Test (see sidebar).

Resined Stones: If the stone is resined1, it may not need sealing. Perform the absorbency test to be sure.

Choosing the Correct Sealer

Many factors need to be considered when choosing the correct sealer.

  1. Stone type:

    Many, if not most stones today are resined at the factory. Resining adds strength to more fragile stones thus creating a much larger supply of natural stones that can be used. You can learn more about resining by searching the Knowledge Base at www.stoneandtilepros.comAll stone is not created equal. How porous a stone is and how fast it will absorb a liquid is called the absorption coefficient. This coefficient is extremely important when choosing a sealer.Granite generally will have a higher absorption coefficient than a polished marble. Limestone can be extremely absorbent. The higher the absorption coefficient, the more difficult it will be to seal the stone adequately. (See sidebar for Stone Absorbency Test)

  2. Stone Finish:

    The finish on a stone affects its absorption coefficient. A polished surface will be less absorbent than a honed or flamed finish. The above absorption test will determine how absorbent a stone is.

  3. Stone location:

    Where is the stone located? Is the stone on the floor, wall, countertop? Is it in a kitchen, foyer, lobby, bathroom? What are they chances of it being subjected to spills or staining agents? Exposure to water, oil, heavy traffic, pets, etc. all need to be taken into consideration when choosing the proper product for protection. For example, a marble kitchen floor that is used daily will need a sealer that has both oil and water repellant properties. At the other end of that spectrum, dealing with a front foyer may only need a water repellant sealer.When protecting a busy hotel lobby floor, don’t be falsely assured that a wax coating will provide the optimal solution. It may track and scuff too easily, requiring costly upkeep. A quality impregnator and a polishing program may be needed to maintain the shine and protection.

  4. Current Maintenance:

    How is the stone maintained? Is it exposed to harsh cleaning chemicals not intended for natural stone? On the other hand, if maintenance is neglected, a stone floor will have ground-in dirt and grit and if it has a high polish it will be worn. In this case, no matter how well it is protected, it will get dirty and dull. For example, a moderately busy hotel lobby floor that gets dust mopped and wet mopped every day may need a good quality impregnator. On the other hand, a stone foyer floor located in a home and not receiving any traffic does not need daily cleaning. An application of a water repellant impregnator may be all that’s necessary.The type of stone, its finish, its location, and how it is maintained all need to be considered when determining how to protect it. Evaluate each of these parameters carefully.How do we protect stone and other porous materials from staining? There are so many sealers on the market today. Which ones are best? Which ones really work?It can be very confusing trying to choose a sealer to protect stone. In the past several years the stone restoration and janitorial industries have bombarded the market with hundreds of products to seal, protect and polish stone.Fortunately, all of these products fall into only two major categories:

    1. Coatings
    2. Impregnators (Penetrating) Sealers

Coatings:

Coatings are sealers that place a sacrificial coating on top of the stone acting as a barrier to prevent water, oil and dirt from entering the pores of the stone.

Coatings can be classified into two general types:

  1. Strippable
  2. Permanent

Strippable Coatings

Strippable coatings are coatings that are designed to be easily stripped or removed from the surface of the stone. These coatings are made of polymers consisting of acrylics, styrene, polyethylene and others. They are usually water based. Many of the janitorial products are water based polymer type coatings. To identify these coatings look for terms on the label such as “metal cross link,” “high solids,” “high speed,” “acrylic,” “thermoplastic,” etc. When in doubt, ask. There are hundreds of different formulas of strippable floor coatings.

Most of them are designed for resilient tile floors and not for stone. If a coating is to be used, be sure it is specified for stone.

Permanent Coatings

Permanent coatings are coatings that are very difficult to remove. They are made of solvent based polymers such as polyurethane, epoxies, etc. These are not recommended for stone.

Impregnators (Penetrating) Sealers

Impregnators are designed to penetrate below the surface of the stone and deposit solid particles in the pores of the stone or to coat the individual minerals below the surface of the stone. Water, oil and dirt are restricted from entering the stone.

Impregnators can be solvent or water based and usually contain silicone, siloxane, silane, methyl silicate or other similar silicon derivatives. The latest impregnators now contain fluoropolymers2.

Impregnators may also be classified as Oleophobic /Lyophoic (oil repelling) or Hydrophobic (water repelling).

Hydrophobic impregnators are designed to repel only water and water-based chemicals. Fruit drinks, coffee, tea, soda, etc. would be repelled by a hydrophobic impregnator.


1 Infused with resins at the factory to increase strenght and density.

2 Fluorocarbons are also lipophobic and oleophobic.

3 Lipophobicity, also sometimes called lipophobia (from the Greek λιποφοβία from λίπος lipos “fat” and φόβος phobos “fear”), is a chemical property of chemical compounds which means “fat rejection”, literally “fear of fat”. Lipophobic compounds are those not soluble in lipids or other non-polar solvents. From the other point of view, they do not absorb fats.


 

“Oleophobic” (from the Latin oleum “oil”, Greek ελαιοφοβικό eleophobico from έλαιο eleo “oil” and φόβος phobos “fear”) refers to the physical property of a molecule that is repelled from oil.

The most common lipophobic/oleophobic substance is water.

Oleophobic Impregnators

Oleophobic impregnators are designed to repel water and oil based liquids. Cooking oil, grease, body oils, etc. would be repelled by an oleophobic impregnator.

An oleophobic impregnator will always be hydrophobic, but a hydrophobic impregnator may not be oleophobic. Be sure to read product labels carefully to determine if they it is limited to being only hydrophobic. Some products are listed as oil resistant. Oil resistant and oil repellant are entirely different. Oil resistant will only slow down the absorption of oil into the stone. Oil repellant will prevent oil from entering the stone. Again, read product labels carefully. Be sure you are buying the right product for your particular situation.

NOTE —- Impregnators with Fluoropolymers are both oleophobic and hydrophobic.

IMPORTANT: Impregnators will do nothing to protect acid-sensitive stones from etching. They are designed to penetrate the stone’s surface to create a shield to protect staining agents from penetrating below the surface of the stone. Etching occurs on the surface of the stone.

COATING OR IMPREGNATOR?

How do you make the determination between a coating or an impregnator? They both have their advantages and their disadvantages. The following summary should be considered carefully when choosing the proper product:

Coatings – Advantages

Coatings are sealers that place a protective, sacrificial layer on the surface of the stone.

  1. Coatings are generally economical. The initial application is relatively low.
  2. Coatings are generally easy to apply. Unskilled labor can learn to apply them in a short time.
  3. Coatings generally will provide a sacrificial coating on the stone. This layer will take most of the wear, preventing wear on the stone.
  4. Certain coatings will provide added slip-resistance. (Although there are slip resistant treatments available just for natural stone surfaces.)
  5. Coatings can be applied below grade. If a floor is located below ground level, a good coating may prove beneficial for protecting or waterproofing.
  6. Coatings will generally provide various degrees of luster.

Coatings-Disadvantages

  1. Since most coatings are typically softer than the stone itself, they will usually scratch, mar and scuff very easily, showing traffic patterns soon after application. This will require frequent buffing, burnishing or re-application.
  2. Coatings can build up and can cause an unsightly appearance, producing an unnatural, wavy, plastic look to the stone.
  3. Poor quality coatings can turn yellow. This is especially true if the stone is exposed to UV light.
  4. Coatings require frequent stripping and reapplication. The chemicals and abrasives used in the stripping process may cause damage to the stone. Typically, certain stripping pads and stripping brushes can scratch some softer stones.
  5. Some wax strippers can harm certain stones such as agglomerates, eating away at the polyester binders.
  6. Certain coatings may block the breathing capability of the stone. Moisture can become trapped below the surface and may lead to spalling.

Impregnators-Advantages

  1. Most impregnators will not change the appearance of the stone.
  2. Most impregnators do not require frequent applications. Since the impregnator is below the surface, it will generally last several years before reapplication is necessary.
  3. Most impregnators are not affected by UV light since they are below the surface where UV light cannot penetrate. For this reason they can be used outdoors.
  4. Impregnators are typically hydrophobic, while some are oleophobic.

Impregnators – Disadvantages

  1. Impregnators that are solvent-based produce noxious and flammable vapors during application.
  2. Solvent-based impregnators are harmful to the environment producing high VOCs (volatile organic compounds). For this reason, some are restricted in certain states. Always check the Safety Data Sheet (MSDS/SDS).
  3. Impregnators require a semi-skilled person for application. Proper training is highly recommended.
  4. The initial cost of most impregnators is relatively high.
  5. Impregnators in general cannot be used below grade to resist hydrostatic pressure. Since the stone is still capable of breathing, water can be forced through the stone by pressure.When choosing the proper product for protection, the above guidelines should help. Always talk with the manufacture or distributer, and let them know where you plan to use their product. They can be very helpful if you tell them all the conditions that apply.

Sealing: Do it Yourself or call in a PRO?

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.

The obvious pro for doing it yourself is you save on labor costs. However, if it is not done correctly it could result in problems.

For example, the surface must be thoroughly and completely cleaned. If not, you take the chance of sealing in dirt and debris. Also, keep in mind that the sealer is intended to fill the pores and coat the exposed minerals in the stone, not to coat the surface. If residual sealer is not completely removed from the surface of stone, it may cause problems, including a haze on the stone’s surface that may develop as the sealer dries. Once it has dried completely, sealer can be very difficult to remove, often requiring professional assistance.

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.

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Testimonials

JMC did an outstanding job sealing the grout for the floor tiles and shower tiles. JMC also sealed the granite counter tops. The price was competitive and reasonable. The owner, Justin, personally performed the work. The good experience started with him showing up at the scheduled time. He was diligently focused on performing a good job. He applied several coats of sealer to the granite tops to insure a quality job. He spent hours sealing the grout for over 2,000 sq ft of floor tile. His enthusiasm and attention to quality never waivered. I highly recommend using their services.

Steve Temecula CA

Justin helped my husband and I repair a large crack in our granite slab. He not only repaired the crack but resealed all of our other countertops too. His price was very competitive and he kept his word on when he was available and showed up on time. What more could you have asked for! Thank you Justin!!

Misty Temecula CA

Justin did an amazing job color enhancing and sealing our slate floors. I called and met with several tile cleaning companies, but chose Justin because I felt he was the most honest, knowledgeable, and experienced. He took the time to explain different options and even showed me a small area before he continued with the entire floor. He spent hours prepping, cleaning, enhancing, and sealing our slate. His work paid off...our floors are finally gorgeous! He changed our dull, chalky looking slate by giving it a brilliant luster that enhances our home. I could not be more thrilled with the results. Bottom line, Justin did exactly what he said he would at the cost we agreed to and even changed his personal schedule to accommodate my schedule. He went above and beyond. In a time when I feel it is difficult to find good, honest, hardworking people to hire, Justin at JMC Tile and Grout has changed my mind. Thank you Justin!

Laura Temecula CA

Justin is very professional. He has done 2 separate marble polishing jobs for us and each time we have been very pleased. He is very thorough and careful, doing a great prep job to prevent any damage. His prices are very fair. So glad we found Justin. There are very few marble and stone care professionals in this area. Highly recommend Justin!

Diane Murrieta CA

Justin came in and cleaned and resealed the grout on our floors. He was a very professional and easy person to talk to. He was also very helpful with other things around the house. Great guy and great job. Well done!!! Thank you!!!

Helene Temecula CA

Justin did an excellent job of repairing a large crack in our kitchen granite. It was quite deep and covered a large area. Needless to say it was very noticeable and would have caused us to replace an entire slab of granite if we had not had it repaired. He spent almost an entire morning in the restoration. He was meticulous in his work, was able to match the color of the granite and it looks 100% better. In addition he resealed and polished all the rest of our granite countertops. We certainly would recommend him. He was professional, very neat and thorough. He arrived exactly on time, even though he had to drive an hour to reach us. He will certainly be someone we contact again if we need any more restoration or maintenance on our granite. We were delighted with his work. Cyndi M. Coronado

Cyndi Coronado CA

Justin is the man. My wife and I recently moved into our new home in Lake Elsinore, we thought that we would seal the grout on our floors and shower by ourselves. After realizing the size and scope of the grout sealing project we decided to contact an expert to get an estimate. I had read online that most tile companies charge about $1.00 per square foot so I had an idea how much the estimate would be. Justin came out the same day and gave my wife the estimate. Since we did not have any furniture in the house yet we asked if he could start the same day. It was already 2pm at that point and Justin was not sure if he had enough sealer with him to do the whole job. He agreed to start sealing the grout near the walls where the heavy furniture would be placed and come back later to finish the job another day. After he started sealing our grout he found more sealer in his work van and decided that he would just power through and finish the job for us the same day! We were thrilled with the entire experience. Justin is truly a tile and stone professional. When he was finished sealing the grout he also sealed our new granite counter tops. All I can say is, if we ever have a tile or stone job in the future, Justin is "our guy." Great service with top quality products and fair pricing, what more could you ask for? Also, at no point during the job did he attempt to up-sell us anything, as a matter of fact, he tried to lower his price once the job was finished but we wouldn't hear of it. We agreed to a set price and that is what he deserved. Thanks Justin, you saved us a lot of time and energy. I can sleep better at night knowing that our expensive new flooring is protected for many years to come. I would highly recommend JMC Stone & Tile to friends and family.

Lake Elsinore CA

Justin thank you so much for the wonderful job you did restoring my marble floor. Very professional and I will recommend your service to all our friends. Thank you Elizabeth, Riverside County

Elizabeth , Riverside County

Thank you Justin at JMC Stone and Tile Care. He re colored our grout with color seal and it looks amazing. His attention to detail to customer service is top notch and I have no problem referring your services. If your in Temecula CA JMC Stone and Tile Care is my recommendation for all your tile, stone, and color sealing needs. Thank you so much

Cathi Cameron, Temecula CA

We are so happy with the service from Justin at JMC stone and tile care. He re colored are old nasty stained grout on our countertops with color seal. The grout looks brand new he will be referred to all our friends in Murrieta CA.

Julie Johnson Murrieta CA

Justin (JMC Stone and Tile Care) cleaned the tile and grout of my floors in April 2013. On the day he was at my home to provide a quote and also on the day of service, Justin was prompt, courteous and professional. Once involved in the job and realizing that part of my floors was not as badly in need of cleaning as the rest of the tile, he reduced the cost of the service. I very much appreciated his fairness and integrity! Not only did my floors looks sparkling clean when he was done, but I also knew much more about how to keep my floors clean on my own. He was quick to share secrets of his trade! I recommend Justin’s service without reservation. His service is unparalleled, and he is a friendly and honest professional! Gail Miller Temecula CA

Gail Miller Temecula CA

Justin, I would like to thank you again for the excellent job you did repairing and retiling our marble tile table. I would definitely use your services again and recommend you to anyone needing stone or tile work done in Murrieta CA. Thank you, Heather Lumsden

Heather Lumsden Murrieta CA

We have been very pleased with the service that Justin has given us. The overall quality of his work was excellent. In one small area we had a slightly rough feel to the sealant he had applied to our granite countertops. Justin returned on the very day that we called him and quickly repaired it. This is a very courteous, professional, and above all, competent service in Murrieta CA. Thanks so much John Welniak

John Welniak. Murrieta CA

February 14, 2013 Justin We are absolutely thrilled with our new floor!!!! Yes, I say new floor because that is the way the whole house looks! It looks like brand new tile. Justin, you did a fabulous job! Thank You, Judy Nitti

Judy Nitti Temecula CA

I accidentally spilled some cleaner on our marble vanity and made those awful etch marks. I called Justin at JMC Stone and Tile Care and he assured me that I didn't ruin my bathroom vanity. Thanks so much for removing those etch marks, we will definitely refer you to anyone in Wildomar CA.

J. Escarsega, Wildomar CA

I would like to thank Justin of JMC Stone and Tile care for bringing back the beautiful shine to our granite countertops. Very professsional and courteous and on time. It's hard to find all those qualities in one place. Thanks Justin again and we are clients for life and we will definitely refer you to anyone in Oeanside Ca.

Lacey Linek, Oceanside CA

We had a last minute emergency and we had a surprise visit from an important client. We called a few tile and stone companies and not one would help us. We called JMC Stone and Tile Care and Justin rescued us. He was very professional and accommodating to our last minute request to have the tile cleaned. For that we can't thank you enough and will refer you to anyone in Carlsbad CA.

Kyle Batsford, Palomar Reprographics, Carlsbad CA
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