Granite is a popular choice in kitchens, bathrooms and flooring, for its durability and natural beauty. But did you know it can be surprisingly absorbent? Much like wood, granite has pores that can absorb liquids and lead to stains. This raises an important question: does granite need to be sealed? Yes, it does.

While some granite comes pre-sealed from the manufacturer, many do not. Sealing your granite can protect it from etching and permanent damage, ensuring it remains in excellent condition.

In this post, I’ll explore why granite should be sealed, how to test your granite, and DIY vs professional services. Let’s get started.

Key Takeaways

1. Granite must be properly sealed to prevent stains and damage.
2. Perform a water test to determine whether you need to reseal your granite.
3. Seal your granite at least once a year or more frequently for high-traffic areas.
4. Maintain sealed granite with gentle cleaners and protective practices to keep it looking new.

Does Granite Need to be Sealed?

Granite is an igneous rock containing various natural materials like quartz, feldspar, and mica. Despite its hardness, granite is porous, making it surprisingly absorbent. This means liquids such as water, cooking oil, red wine, even grape juice, cordials and soft drinks can seep into the stone’s pores, leading to stains or damage.

How Sealants Work

Sealants protect your stone surface. A high-quality sealant blocks substances like grease, ethanol, and acidic solutions from penetrating the stone’s porous surface. Without sealing, common kitchen items such as dishwashing soap or cleaning products can seep into the granite, causing etching and discolouration over time.

However, over-sealing can result in a glazed appearance, so it’s essential to seal only when necessary.

Sealing granite countertops in kitchens and bathrooms helps to maintain their beauty and longevity. By protecting your granite from liquids and acid spills, you can prevent permanent damage and keep the stone looking its best for years.

In addition to stain prevention, sealing maintains the granite’s natural shine and beauty. Unsealed granite can become dull, especially if exposed to frequent spills or harsh chemicals. By applying a sealant, you ensure your granite benchtops retain their glossy finish and remain easy to clean.

How To Check If Your Granite Needs Sealing

The Water Test

To determine if you need to seal your granite surfaces, perform a simple water test. Here’s how:

1. First, clean the surface using a mild soap and water solution. This ensures that no grease or residue interferes with the test.
2. Dry the granite with a paper towel or microfiber cloth.
3. Pour a small amount of water (a teaspoon or two) onto the granite surface and observe. If the water beads up and remains on the surface for 15 minutes without soaking in, your countertop’s sealant is effective. 
4. If the water soaks into the granite and darkens the stone, it indicates that the sealant is failing, and resealing is necessary.

We recommend repeating this test every six months, especially in high-traffic areas like kitchens and bathrooms.

Apart from the water test, there are other signs that indicate your granite countertops need to be resealed. If you notice that the surface feels rough or has lost its shine, it’s a clear indication that the sealant has worn off.

Additionally, if you see stains forming more easily or if the granite appears to be absorbing liquids, it’s likely your countertops need to be sealed.

The Lemon Juice Test

You can also use lemon juice to test the sealant. Pour a small amount of lemon juice onto your granite surface, choosing an inconspicuous area. Wait for a few minutes before wiping it off with a paper towel. Observe any changes on the surface.

If the lemon juice leaves a dark spot or the granite absorbs it, the sealant is likely compromised or non-existent, and it’s time to reseal. A well-sealed countertop should repel the liquid without any absorption.

This test uses lemon juice’s acidic nature to reveal granite’s porosity. Keep in mind that granite can etch with prolonged exposure to acids, so limit the contact time.

How Often Should You Reseal Granite?

Typically, granite countertops need resealing every 12 to 18 months. Several factors influence how often you should reseal granite. These include:

• Type of Granite: Lighter coloured granite requires more frequent resealing. This is due to a combination of its higher porosity and the fact the colour shows stains easier than darker granite. 
• Usage and Wear: In high-use areas, the combination of heat, acid, and liquids involved in food preparation can degrade the sealant faster.
• Sealant Quality: The specific granite sealant you use can impact how often you need to reseal. High-quality, long-lasting sealants might cost more but reduce the frequency of application. That’s why we recommend professional stone sealing over do it yourself products.

What Happens if You Don’t Reseal Granite Countertops?

Unsealed granite becomes susceptible to various liquids, such as water, red wine, and cooking oil, which can seep into the porous surface. These substances penetrate the granite, leading to permanent stains. Red wine, for example, leaves unsightly marks that are difficult to remove.

Unsealed granite also becomes more prone to etching. Acidic substances like lemon juice react with the minerals in the stone, causing dull spots and surface damage. You can see this in the image above. Over time, the granite countertop loses its polished appearance, diminishing its aesthetic value.

Frequent exposure to moisture also contributes to the stone’s deterioration. In bathrooms, water splashes and humidity accelerate the growth of mould and mildew in unsealed areas. This increases the risk of bacterial buildup, compromising hygiene.

In addition, not resealing the granite can lead to discolouration. Water and other liquids leave behind mineral deposits, altering the granite’s natural look. Regular resealing creates an effective barrier, preserving the stone’s original colour and shine, to keep them looking new.

If you have etching, mould, or discoloured granite, it might be time for granite restoration.

Do All Granite Surfaces Need To Be Sealed?

Not all granite surfaces require sealing. In some cases, manufacturers pre-seal granite countertops, eliminating the need for immediate sealing. For instance, companies might use a 15-year lifetime sealer for added protection. How long this actually lasts though depends on how well you look after it.

Maintaining sealed surfaces involves regular cleaning with mild soap and water, avoiding harsh chemicals like bleach, which can degrade the sealant over time. For long-lasting results and optimal protection, reseal granite countertops every 12 to 18 months, with lighter-coloured granite requiring more frequent upkeep due to higher porosity.

How to Seal Granite The Right Way

Before you start sealing, it’s important to clean your granite countertops thoroughly. Use a granite-specific cleaner or a mild dish soap and water to remove any dirt, grease, or residue. Make sure the countertops are completely dry before applying the sealant.

This may take up to 24 hours, depending on the humidity and temperature. Humidity keeps more moisture in the air, so the stone takes longer to completely dry out. Low temperatures, such as the middle of Melbourne Winter, can affect drying times. If you have central heating or an air conditioner, turning this on will help speed up the process.

Choose the Right Granite Sealer

There are two main types of granite sealers: penetrating sealers and topical sealers. Penetrating sealers are absorbed into the stone and provide long-lasting protection from within. They are ideal for high-traffic areas and offer superior stain resistance.

Topical sealers, on the other hand, sit on the surface of the granite and provide a protective barrier. They can enhance the granite’s shine but may require more frequent reapplication.

At Clean Seal, we use and recommend low VOC water based penetrating sealers.

Applying the Sealant

To seal your granite countertops, follow these steps:

1. Clean the Granite: Give your granite counter a really good clean. Ideally, this should be done the day before sealing (so it has time to dry fully).
2. Choose the Right Sealant: Select a high-quality granite sealer that suits your needs.
3. Apply the Sealant: Apply the sealant evenly across the granite surface. A spray bottle can help with this. Ensure complete coverage, but avoid oversaturating the stone.
4. Let It Soak In: Allow the sealant to penetrate the granite for the recommended time, usually 15-30 minutes.
5. Wipe Off Excess: After the sealant has soaked in, use a clean cloth to wipe off any excess sealant. Make sure no residue is left on the surface.
6. Cure Time: Allow the sealant to cure for the time specified by the manufacturer, typically 24 hours, before using the surface. 

Common Mistakes to Avoid When Sealing Granite

Not Cleaning Properly

One of the most common mistakes is not cleaning the granite countertops thoroughly before sealing. Any dirt, grease, or residue left on the surface can prevent the sealant from adhering properly, reducing its effectiveness.

Always clean and dry the countertops completely before applying the sealant. Ideally, you want to do this the day before sealing.

Not Drying the Stone Completely

Any moisture left can prevent the sealer from penetrating properly, so it’s essential the stone is completely dry.

Overapplying or Underapplying Sealant

Applying too much or too little sealant can also be problematic. Applying too much sealer can cause a sticky, hazy residue, while applying too little may not provide adequate protection. Follow the manufacturer’s instructions carefully to ensure the right amount of sealant is used.

Benefits of Regularly Sealing Granite

Enhanced Durability

Regularly sealing your granite countertops enhances their durability and extends their lifespan. The sealant helps to protect the stone from scratches, stains, and other forms of damage, keeping your countertops looking new for longer.

Easier Maintenance

Sealed granite countertops are easier to clean and maintain. The sealant creates a smooth surface that prevents dirt and spills from penetrating the stone, making it easier to wipe away messes. This reduces the need for harsh cleaning chemicals and helps to keep your countertops looking pristine.

DIY vs. Professional Sealing: Which is Better?

Many homeowners attempt to seal granite themselves. With the right tools and a bit of patience, you can achieve excellent results. DIY sealing is cost-effective and allows you to control the entire process, ensuring that your countertops are sealed to your satisfaction.

If you’re not comfortable sealing your granite countertops yourself, or if you have large or complex surfaces, hiring a professional may be the best option. Professionals have the expertise and equipment to apply the sealant evenly and effectively, ensuring maximum protection for your countertops.

Tips for Maintaining Sealed Granite Countertops

Regular Cleaning

To keep your granite slab looking its best, clean it regularly with a granite-specific cleaner or a mild dish soap and water. Avoid using harsh chemicals or abrasive cleaners, as they can damage the sealant and the stone.

Avoid Harsh Chemicals

Harsh chemicals, such as bleach or ammonia, can degrade the sealant and damage the granite. Stick to gentle, pH-balanced cleaners specifically designed for natural stone.

Using Cutting Boards and Trivets

Even though granite is highly durable, cutting boards and trivets can help to prevent heat damage and stains and scratches. This simple practice will help to preserve the sealant and the stone’s surface.

Frequently Asked Questions

Conclusion

Sealing granite is an essential part of home maintenance. By understanding the importance of sealing, knowing how to determine when your countertops need to be resealed, and following the proper sealing procedures, you can protect your investment and enjoy the benefits of stunning granite surfaces.

Whether you seal your countertops yourself or hire our professional team, regular sealing will keep your granite countertops looking new and performing at their best.

We're The Right Company To Restore Your Natural Stone

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