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 turning orange is primarily caused by the oxidation of iron minerals within the stone. When these iron elements are exposed to moisture and oxygen, they undergo a chemical reaction, resulting in rust-like discolouration. 

Here’s a detailed breakdown of the causes:

• Natural Iron Deposits: Bluestone contains iron minerals that can oxidise when exposed to the elements.
• Moisture Exposure: Water from rain, sprinklers, or pooling amplifies the risk of oxidation, especially if the bluestone remains wet for extended periods.
• Oxygen Interaction: Oxygen in the air reacts with the wet iron deposits, leading to rust stains.
• Environmental Factors: High humidity or frequent wet conditions in certain climates can accelerate staining.
• Poor Drainage: Areas with inadequate drainage are more prone to sustained moisture, which can increase the occurrence of orange stains.
• Protective Sealant Wear: Over time, the protective sealant on bluestone can wear off, increasing vulnerability to moisture and oxidation.

Preventing Discoloration

Preventing discolouration in bluestone primarily involves managing moisture exposure and ensuring the stone is well-maintained. Here are specific measures to help keep bluestone looking its best:

• Sealing the Stone: Apply a penetrating sealer to bluestone to help repel water and reduce moisture absorption. Sealers should be reapplied every one to two years, depending on exposure to elements and foot traffic.
• Improving Drainage: Ensure the installation area has adequate drainage to prevent water pooling on the bluestone. Consider sloping the installation away from buildings to facilitate better water runoff.
• Routine Cleaning: Regularly clean bluestone using a pH-neutral cleaner to remove dirt and debris that can trap moisture. Avoid acidic cleaners, which can increase the risk of oxidation.
• Prompt Stain Management: Address spills and stains quickly to prevent the substances from seeping into the pores of the bluestone, where they can react with minerals.
• Covering When Possible: In areas with frequent rain or snow, consider covering bluestone during the off-season to minimise water exposure.
• Use of Rugs or Mats: Place rugs or mats in high-traffic areas to reduce the amount of water and debris brought onto the bluestone.

Cleaning and Restoration

Cleaning and restoring bluestone that has turned orange due to iron oxidation involves specific steps to effectively remove the discolouration and protect the stone for the future:

• Identify the Stain: Confirm that the discolouration is indeed iron oxidation, characterised by orange or rust-like stains.
• Choose the Right Cleaner: Use a cleaner specifically designed for rust removal on stone. These products typically contain oxalic acid or phosphoric acid, which can break down iron stains without damaging the bluestone.
• Apply the Cleaner: Follow the manufacturer’s instructions for application. Generally, apply the cleaner to the stained area and allow it to sit for the recommended time to penetrate and react with the rust.
• Scrub Gently: Use a soft brush to scrub the area gently. Avoid using abrasive tools that could scratch the stone.
• Rinse Thoroughly: After scrubbing, rinse the area thoroughly with clean water to remove any residue of the cleaning solution.
• Dry and Assess: Allow the stone to dry completely. If stains persist, repeat the cleaning process.
• Reapply Sealant: Once the stone is clean and dry, apply a high-quality sealant to help prevent future staining.

Maintaining Bluestone’s Natural Beauty

Maintaining the natural beauty of bluestone involves regular care and preventative measures to protect the stone from damage and discolouration:

• Sealing the Stone: Apply a high-quality sealer to the bluestone to protect against moisture and stains. Seal every two to three years, depending on the exposure and traffic levels.
• Routine Cleaning: Regularly clean the bluestone using a pH-neutral cleaner to remove dirt and potential contaminants. Avoid harsh chemicals or acidic cleaners that strip the sealant and expose the stone to staining.
• Immediate Stain Response: Clean spills and stains immediately to prevent them from setting and causing permanent discolouration. Blot spills rather than wiping to avoid spreading the stain.
• Avoid Abrasive Tools: Use a soft brush or mop to clean. Avoid steel wool, wire brushes, and abrasive scrubbers, which can scratch the stone.
• Inspect Regularly: Inspect bluestone for signs of wear, such as fading sealant or emerging stains. Early detection and maintenance can prevent more extensive damage.
• Professional Cleaning: Consider professional cleaning services for deep stains or when preparing to reseal the bluestone, ensuring a thorough and safe cleaning process.

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.