Natural stone brings character and lasting quality to Australian kitchens and bathrooms, making it a popular choice for premium benchtops. While materials such as marble, granite and quartzite are durable, they are also porous. The right benchtop protection helps reduce moisture and stain absorption, preserving the appearance and performance of the stone over time.
Does natural stone need to be sealed? In most cases, yes. Natural stone sealing reduces the amount of liquid that can penetrate the surface, helping protect against staining from oils, food, drinks and moisture. The type of stone, its finish and how the benchtop is used will determine how often sealing is required.
Learn more about MSM Stone’s stone benchtop installation services.
Does Natural Stone Need to Be Sealed?
Yes, most natural stone benefits from sealing. Stone contains tiny pores that can absorb water, oils and other liquids, potentially leaving stains or discolouration behind. Sealing natural stone reduces this absorption by treating the pores within the surface, making it more resistant to liquids and staining. The level of protection required depends on the type of stone, its finish and how frequently the benchtop is used.
What Is Stone Porosity?
Porosity refers to the tiny spaces within natural stone that allow liquids to penetrate the surface. More porous stones absorb liquids faster, while denser stones absorb them more slowly. The stone’s density and finish therefore affect how readily it absorbs moisture and how frequently it may need resealing.
Marble vs Granite vs Quartzite: Do They All Need Sealing?
Marble: Marble is porous and particularly reactive to acidic substances such as citrus, wine and vinegar. Sealing helps reduce staining, although it won’t protect the surface from acid etching.
Granite: Granite is generally denser and less absorbent than marble, but porosity varies between slabs. Sealing provides additional protection against oils, liquids and everyday spills.
Quartzite: Quartzite is typically dense and durable, although its porosity can vary depending on the individual stone and finish. Some varieties will absorb liquids more readily than others.
For kitchen benchtops, all three natural stones can benefit from appropriate sealing to reduce staining and maintain their appearance over time.
What Is Benchtop Protection and How Does It Work?
Benchtop protection reduces the amount of liquid that can penetrate natural stone, helping limit staining and moisture absorption. There are two main approaches: penetrating sealers, which absorb into the pores of the stone, and surface coatings, which form a layer over the benchtop. The right option depends on the type of stone, its finish and the level of protection required.
Penetrating Sealers
Penetrating sealers soak into the pores of natural stone, reducing its ability to absorb water, oils and other liquids. They maintain the stone’s natural appearance rather than creating a visible layer on the surface and remain breathable, allowing moisture vapour to escape. For this reason, penetrating sealers are generally preferred for premium natural stone benchtops.
Surface Coatings
A benchtop protection coating sits on top of the stone rather than penetrating its pores. Depending on the product, it may alter the sheen, colour or texture of the surface, so careful product selection is important. Surface coatings can provide an additional barrier against staining, but their level of protection varies and they should not be assumed to prevent etching.
Does Sealing Prevent Etching?
No. Natural stone sealing helps reduce staining and liquid absorption, but it does not prevent acid etching. Marble is particularly susceptible to etching when acidic substances such as lemon juice, vinegar or wine react with the stone. Spills should still be wiped up promptly, even when the benchtop has been properly sealed.
Why Sealing Natural Stone Is Essential for Long-Term Performance
Natural stone is a significant investment, and sealing provides an important layer of protection against everyday use. In a busy kitchen, repeated exposure to cooking oils, food, drinks and moisture can gradually affect an unprotected surface. Proper sealing reduces absorption and can help the benchtop retain its appearance and performance for longer.
What Causes Stone Benchtop Stains?
Common kitchen spills can leave lasting marks if they’re absorbed into unsealed stone. Cooking oils, red wine, coffee and strongly pigmented ingredients such as turmeric are common culprits. The more porous the stone, the faster a spill may penetrate, making prompt clean-up particularly important. Citrus and certain cleaning chemicals can also damage sensitive stones, although these are more likely to cause etching than staining.
What Happens If You Don’t Seal Natural Stone?
Without appropriate sealing, porous stone is more likely to absorb liquids, resulting in staining, dark patches and discolouration. In bathrooms and other wet areas, ongoing moisture exposure can also contribute to discolouration, deterioration and conditions in which mould may develop. Some damage may require specialist cleaning or professional restoration to correct, while deeper staining may be difficult to remove completely. Proper sealing helps reduce these risks before damage occurs.
When Should You Seal or Reseal a Stone Benchtop?
Natural stone should be sealed after installation and then resealed as needed over time. How often depends on the stone, its finish and how heavily the benchtop is used. More porous materials and high-use kitchens may need attention sooner, while denser stones can often go longer between applications. Rather than relying on a fixed schedule, check how the surface is behaving and follow the sealer manufacturer’s guidance.
Should You Seal Stone After Installation?
Yes. New natural stone is typically sealed once fabrication and installation are complete. Correct initial sealing helps reduce liquid absorption from the outset and provides a stronger foundation for long-term benchtop protection. MSM Stone can advise on the appropriate sealing requirements as part of a professional stone benchtop installation.
How Do You Know If Your Benchtop Needs Resealing?
A simple water drop test can help indicate whether the sealer is still working:
- Place a few drops of water on a clean, dry section of the benchtop
- Leave them for several minutes
- Wipe the area dry
- Check for any visible darkening
If the stone darkens where the water sat, moisture is being absorbed, and resealing may be needed.
How to Seal Natural Stone Countertops Properly
Knowing how to seal natural stone countertops correctly starts with choosing a sealer suited to the specific stone and finish. Application instructions and curing times vary between products, so always follow the manufacturer’s directions rather than using a one-size-fits-all method.
Step 1: Clean the Surface Thoroughly
Before applying sealer, the stone must be clean and completely dry. Remove grease, food residue and existing cleaning products using a stone-safe cleaner, as contaminants left on the surface can interfere with absorption. For everyday preparation and cleaning advice, see MSM Stone’s guide to cleaning stone benchtops.
Step 2: Apply the Sealer Evenly
Apply the recommended amount of sealer evenly across the stone, following the product instructions for application and dwell time. Allow it to penetrate for the specified period, then remove any excess before it dries on the surface. Leaving excess sealer behind can result in streaks, haze or an uneven finish.
Step 3: Allow Proper Curing Time
Give the sealer the full recommended curing time before exposing the benchtop to water, spills or food preparation. This gives the sealer time to cure properly within the stone. Using the surface too soon can compromise the effectiveness of the seal, so check the manufacturer’s specified curing period before returning the benchtop to normal use.
Professional Sealing vs DIY: What Should You Choose?
DIY sealing can be suitable if you know the exact type of stone you’re working with and are confident choosing and applying the correct product. Professional sealing offers the advantage of having the stone and its finish assessed first, followed by appropriate product selection and even application. This can be particularly valuable for premium marble, granite or quartzite, where mistakes may affect the finished surface.
For a new benchtop, correct sealing should be considered from the outset. MSM Stone can advise on the appropriate protection when professionally fabricating and installing your natural stone benchtop, helping it retain its appearance for years to come. Contact MSM Stone to discuss your stone selection, installation and long-term care requirements.
Frequently Asked Questions
Does natural stone need to be sealed in a kitchen?
Yes, most natural stone benchtops benefit from sealing in a kitchen. Marble, granite and quartzite contain microscopic pores that can absorb oils, liquids and other spills. Natural stone sealing reduces this absorption, helping protect the surface from staining and discolouration. The appropriate sealer and frequency will depend on the type of stone and its finish.
How often should you seal natural stone benchtops?
Natural stone benchtops should be resealed as needed rather than according to one fixed schedule. The interval can vary considerably depending on the stone’s porosity, finish, sealer used and level of daily use. More porous surfaces may need attention sooner, so periodically checking for increased water absorption is a more reliable guide.
How do I know if my benchtop needs resealing?
A simple water test can help indicate if your benchtop needs resealing. Place a few drops of water on the clean stone and leave them briefly before wiping them away. If the area underneath darkens as the water is absorbed, the existing sealer may no longer be providing sufficient protection. Ask a stone professional for advice before applying a new product.
What is the best sealer for marble benchtops?
A high-quality penetrating sealer formulated specifically for natural stone is generally suitable for marble benchtops. These products penetrate the pores rather than creating a coating over the surface, helping reduce liquid absorption while retaining the stone’s natural appearance. The best product will depend on the particular marble and finish, so check the stone and sealer manufacturer’s recommendations before application.
Can sealing natural stone prevent stains completely?
No, sealing natural stone cannot prevent stains completely. A quality sealer reduces the rate at which liquids penetrate the stone, giving you more time to clean up spills before they are absorbed. It does not make natural stone stain-proof, and spills should still be wiped up promptly. Sealing also does not protect marble and other acid-sensitive stones from etching.
