Granite countertops are synonymous with durability, elegance, and long-term value. As a natural stone, granite is a popular choice in both residential and commercial projects due to its distinctive veining, timeless appeal, and hardwearing nature. However, to maintain its integrity, longevity, and appearance, proper sealing is essential.

At International Granite Company, we are committed to educating our customers on best practices for granite care. 

Fundamentals of sealing granite countertops

1. Introduction to Granite Porosity

Granite is an igneous rock composed of minerals such as quartz, feldspar, and mica. Although it is one of the hardest natural stones available, granite is inherently porous. This means that without protection, liquids and oils can seep into its surface, causing staining, discolouration, or even bacterial growth.

Porosity levels can vary depending on the mineral composition and density of the stone. Some granite varieties are more absorbent than others, which is why understanding your specific slab is critical in determining sealing requirements.

2. Why Sealing Granite is Essential

Sealing granite adds a protective barrier that reduces its porosity. This barrier is vital for several reasons:

• Stain Protection: Everyday substances like wine, oil, and citrus juices can permanently stain unsealed granite.

• Bacteria and Mould Resistance: Sealing helps prevent bacteria from penetrating the surface, promoting a more hygienic kitchen or bathroom environment.

• Enhanced Appearance: A good quality sealer enhances the stone’s natural colour and pattern, preserving its beauty over time.

• Longevity: Regular sealing helps prevent etching, moisture damage, and general wear, ultimately extending the life of your investment.

For property developers, designers, and discerning homeowners, sealing is not just a precaution—it’s a value-preserving necessity.

3. How to Know If Your Granite Needs Sealing

The simplest way to assess whether your granite countertop needs sealing is through the water drop test:

1. Pour a few drops of water on the surface.

2. Wait 10–15 minutes.

3. If the water darkens the granite or absorbs into the stone, it’s time to seal.

Other tell-tale signs that resealing is needed include:

• Dull or uneven finish

• Watermarks that persist after cleaning

• Susceptibility to oil stains or dark patches

It’s important to test each section of your countertop, especially if it includes different slabs or high-use zones like around sinks or stovetops.

4. When Should You Seal Granite Countertops?

Granite should be sealed at the following intervals:

• Upon installation, most granite is sealed immediately after fabrication and before delivery. However, confirm this with your supplier or fabricator.

• Routine maintenance: Depending on the stone and usage, resealing is recommended every 12 to 36 months.

• Heavily used areas (e.g., kitchen islands, food preparation zones) may require more frequent sealing.

Factors affecting sealing frequency:

• Stone porosity (denser stones need sealing less often)

• Exposure to acidic or oily substances

• Cleaning agents used (harsh chemicals can degrade the sealant faster)

5. Types of Granite Sealers Available

There are two main categories of granite sealers:

a. Penetrating (Impregnating) Sealers

These soak into the stone’s surface, forming a barrier below the surface. They are:

• Long-lasting

• Ideal for food preparation areas

• Typically invisible once cured

b. Topical Sealers

These create a film on the surface. They:

• Provide a shiny or matte finish

• Require more frequent reapplication

• Can be prone to peeling if not maintained properly

Sealers are also either:

• Solvent-based: Deeper penetration but may emit strong fumes

• Water-based: More environmentally friendly and easier to apply

At International Granite Company, we recommend penetrating, food-safe, solvent-free sealers for the optimal balance between performance and safety.

6. Step-by-Step Guide: How to Seal Granite

Step 1: Clean the Surface

Use a granite-specific cleaner or a pH-neutral solution. Allow the surface to dry completely.

Step 2: Apply the Sealer

• Pour the sealer directly onto the granite or apply using a clean cloth or applicator pad.

• Spread evenly across the surface.

• Allow the sealer to soak for 10–15 minutes.

Step 3: Wipe Excess and Buff

Using a microfiber cloth, remove any unabsorbed sealer. Buff gently to avoid streaking.

Step 4: Allow Curing Time

Let the surface cure for at least 24 hours before use. Avoid spills during this period.

Mistakes to avoid:

• Over-applying sealer (can lead to a sticky residue)

• Not wiping off excess

• Sealing dirty or damp surfaces

7. Professional vs. DIY Sealing: What’s Right for You?

DIY Sealing

• Suitable for homeowners confident with home maintenance

• Cost-effective and convenient

• Requires careful surface preparation and adherence to instructions

Professional Sealing

• Recommended for large areas or commercial properties

• Ensures correct product selection and expert application

• Often includes cleaning and polishing as part of the service

Whether DIY or professional, always use high-quality sealing products suited for natural stone.

8. Common Myths About Sealing Granite

“Granite never needs sealing”
False. While some denser varieties are less porous, most granite surfaces benefit from sealing to ensure long-term performance.

“All granite is the same”
Incorrect. Granite varies significantly by region, mineral content, and finish. Some stones like Black Galaxy are very dense, while others like Kashmir White are more absorbent.

“Sealing makes granite shiny”
Not always. Sealing protects but doesn’t necessarily change the sheen. Shine is determined by the finish—polished, honed, or leathered—not by the sealer itself.

9. Maintenance Tips to Prolong Sealer Effectiveness

• Use pH-neutral granite cleaners (avoid vinegar, bleach, or ammonia)

• Wipe spills immediately to prevent staining

• Use cutting boards and trivets to reduce wear

• Re-test the seal annually using the water drop method

• Avoid abrasive scrubbers that can degrade the surface

Regular maintenance reinforces your sealing efforts and ensures your countertops remain a focal point for years.

Conclusion: Make Informed Choices for Long-Term Protection

Granite countertops are a significant investment in both residential and commercial settings. Understanding when and how to seal your granite ensures your surfaces stay beautiful, hygienic, and structurally sound for the long haul.

At International Granite Company, we supply premium-grade granite and offer expert guidance on care and maintenance. Whether you’re a homeowner, interior designer, or builder, we invite you to speak to our team about selecting and protecting the perfect stone for your space.

Need advice or quality sealing products?
Visit www.internationalgranitecompany.com to explore our range and connect with a stone care expert today.