Why Is My Bluestone Turning Orange?

Have you noticed your bluestone pavers developing an unexpected orange hue, deviating from their classic blue-grey tones?

This discolouration can be surprising and frustrating when it mars your outdoor spaces’ elegant aesthetic. Various factors, from iron oxidation to improper sealing, could turn your bluestone into an unsightly orange.

In this article, we’ll explore the common causes of this phenomenon and provide you with practical solutions to restore and protect the natural beauty of your bluestone surfaces.

Why Is My Bluestone Turning Orange?

Bluestone turning orange is likely due to iron oxide formation, a common occurrence in natural stone. Exposure to water, oxygen, and certain minerals can cause iron within the stone to oxidise, resulting in orange discolouration. Environmental factors like rainfall and humidity can accelerate this process. Regular cleaning and sealing can help prevent and mitigate this discolouration.

Causes of Orange Discoloration

Bluestone’s natural beauty can sometimes be marred by unexpected orange discolouration. This phenomenon, though concerning, is relatively common and can be traced back to several key factors:

1. Natural Iron Deposits 

Bluestone naturally contains iron minerals, which are harmless when the stone remains dry. However, when exposed to moisture, these iron deposits oxidise and produce orange stains. This is a common issue, especially with bluestone that hasn’t been properly sealed.

2. Moisture Exposure

Continuous exposure to water from rain, sprinklers, or pooling significantly increases the risk of oxidation. Bluestone that stays wet for extended periods allows moisture to penetrate deeper into the stone. This prolonged wetness accelerates the chemical reactions causing discolouration.

3. Oxygen Interaction

Oxidation occurs when iron minerals come into contact with oxygen in the presence of moisture. This reaction produces rust-like stains that are especially visible on lighter-coloured bluestone. Over time, these stains can become more pronounced if not treated.

4. Environmental Factors

Climates with high humidity or frequent rainfall provide ideal conditions for oxidation. In these environments, the combination of moisture and air leads to quicker and more severe staining. This is why orange discolouration is often more prevalent in damp or coastal areas.

5. Poor Drainage

Areas with inadequate drainage leave water to pool on the surface of the bluestone. This standing water provides a sustained source of moisture that encourages oxidation. Poor drainage also increases the likelihood of deeper stains as water infiltrates the stone over time.

6. Protective Sealant Wear

A high-quality sealant is essential to protect bluestone from moisture and oxidation. Over time, sealants can degrade due to wear and exposure to the elements. Once the sealant wears off, the stone becomes vulnerable, making it easier for iron deposits to oxidise.

Preventing Discoloration

Preventing orange discolouration on bluestone requires proactive measures to protect the stone from oxidation and staining. By focusing on proper maintenance, sealing, and environmental management, you can preserve its natural beauty. Here are practical steps to prevent bluestone from turning orange:

1. Apply a High-Quality Sealant

Using a premium stone sealant creates a protective barrier against moisture and oxygen. Ensure the sealant is specifically designed for natural stone and reapply it as recommended, typically every 1–3 years. This prevents water from penetrating the stone, reducing the chances of oxidation.

2. Maintain Proper Drainage

Good drainage is essential to prevent water from pooling on or around your bluestone. Ensure the surface is slightly sloped to direct water away from the stone. Installing drainage systems can also help in areas prone to water retention.

3. Clean Bluestone Regularly

Routine cleaning helps remove dirt, debris, and potential rust-inducing particles. Use a mild pH-neutral cleaner and a soft brush to gently clean the surface. Avoid harsh chemicals or abrasive tools that can damage the sealant or the stone itself.

4. Minimise Metal Contact

Keep metal furniture, tools, or decorative items away from bluestone, as these can rust and transfer stains. If metal objects must be placed on the stone, consider using protective pads or coatings to prevent direct contact. Regularly check for rust and address it promptly.

5. Protect Against Environmental Moisture

Reduce the exposure of bluestone to consistent water sources like sprinklers or downspouts. Adjust sprinklers to avoid direct contact with the stone and ensure downspouts channel water away. For humid environments, consider installing coverings or shade to minimise prolonged wetness.

6. Inspect and Reapply Sealant

Regular inspections ensure the sealant remains intact and effective. Look for signs of wear, such as water absorption or dullness on the stone’s surface. If the sealant appears compromised, reapply it promptly to maintain the protective barrier.

7. Address Stains Immediately

If you notice orange spots forming, act quickly to remove them before they become permanent. Use a stone-safe rust remover or consult a professional for stubborn stains. Early intervention can prevent the problem from worsening.

Cleaning and Restoration

Orange stains on bluestone, caused by oxidation or rust, can often be removed with the right techniques and products. Addressing the stains promptly will prevent them from setting and preserve the stone’s appearance. Here’s how to effectively remove orange stains from bluestone:

• Use a Commercial Rust Remover: Opt for a rust remover specifically designed for natural stone to avoid damaging the surface. Apply the product as directed, focusing on the stained areas, and let it sit for the recommended time. Rinse thoroughly with water to ensure no residue is left behind, as it may dull the stone over time.
• Try a Homemade Cleaning Solution: For mild stains, a mixture of baking soda and water can be effective. Create a paste and apply it to the affected area, allowing it to sit for 15–20 minutes before scrubbing gently with a soft brush. Rinse with water and repeat if necessary for stubborn stains.
• Use White Vinegar for Surface Stains: White vinegar can help lift light stains caused by rust. Dab the vinegar onto the stained area using a cloth and let it sit for a few minutes. Scrub gently and rinse thoroughly with water, ensuring the vinegar is fully removed to prevent etching.
• Pressure Wash for Large Areas: If the staining covers a larger surface, using a pressure washer on a low setting can help. Focus on the stained areas, but avoid excessive force to prevent damage to the stone. Combine pressure washing with a mild stone cleaner for more effective results.
• Apply a Poultice for Deep Stains: For deeper or persistent stains, use a poultice made of a commercial stain remover and an absorbent material like paper towels or talc. Apply the poultice to the stain, cover it with plastic wrap, and let it sit for 24–48 hours. Remove the poultice, rinse the area, and repeat if needed.
• Call a Professional for Severe Stains: If the stains are extensive or resist DIY efforts, consulting a stone care professional is recommended. Professionals can use specialised tools and treatments to restore your bluestone without causing damage.
• Reapply a Sealant After Cleaning: Once the stains are removed, ensure the bluestone is properly sealed to prevent future discolouration. Choose a high-quality sealant designed for natural stone and apply it following the manufacturer’s instructions.

Maintaining Bluestone’s Natural Beauty

Proper long-term care ensures your bluestone remains beautiful and functional for years to come. Begin by applying a high-quality sealant to create a protective barrier against moisture, stains, and wear. 

Reapply the sealant every 1–3 years or as needed, particularly in high-traffic areas or regions with harsh weather conditions. Regular cleaning is essential; use a pH-neutral cleaner and a soft-bristled brush to remove dirt and debris without damaging the stone or its sealant. 

Avoid harsh chemicals, which can degrade the stone’s surface over time. Maintain proper drainage to prevent water pooling, which can lead to oxidation or discolouration. If outdoor furniture or metal objects are placed on bluestone, use protective pads to prevent rust stains. 

Inspect the stone periodically for signs of wear, damage, or staining, addressing issues promptly to avoid costly repairs. By following these steps, your bluestone will retain its natural elegance and durability for the long term.

Conclusion

Addressing the root causes of iron oxidation and water exposure is crucial to preventing bluestone from turning orange. Regular maintenance and proper sealing are critical. 

Contact our experts at Splendour In Stone for personalised advice and professional solutions to keep your bluestone looking its best.