The causes and solutions to stonework defects

Scotland boasts a rich architectural heritage with many buildings constructed using locally sourced sandstone. While this natural material is renowned for its beauty and durability, it is not immune to defects and deterioration. The challenging Scottish climate, with its moisture, temperature fluctuations, and exposure to the elements, can accelerate the decay of stone structures. Here are some of the common defects of stone in buildings in Scotland, their causes, and potential solutions.

Frost Damage

Cause: Scotland’s climate is marked by freeze-thaw cycles, which can lead to frost damage in stone. Water penetrates the stone, freezes, and then expands, causing cracks, spalling, and weakening of the material.

Solution: Properly repointing and sealing the stone can help prevent water penetration. Restorations may be needed to repair extensive frost damage.


Cause: Wind-driven rain can erode the surface of stone buildings over time, leading to a loss of detailing and overall structural integrity.

Solution: Installing weatherproof coatings can protect the stone from erosion. Regular cleaning and maintenance are essential to preserve the stone’s appearance and structure.

Biological Growth

Cause: Algae, moss, and lichen can grow on stone surfaces, not only compromising the aesthetic appeal but also accelerating stone deterioration through the release of acids and the trapping of moisture.

Solution: Removing biological growth through cleaning and using biocide treatments can help keep the stone in good condition. Proper drainage and ventilation can also reduce moisture buildup.


Cause: Cracks in stone buildings can occur due to various reasons, including structural movement, foundation settling, or thermal expansion and contraction.

Solution: Identifying the cause of the cracking is crucial. Repairs may include repointing, sealing, or reinforcing the affected areas.


Cause: Spalling refers to the chipping or flaking of the stone’s surface, which is often due to the freeze-thaw cycle, chemical reactions, or salt damage from de-icing salts.

Solution: Repointing, patching, or in some cases, replacing damaged stones is necessary. Preventing salt and chemical exposure can minimize spalling.

Sulfate Attack

Cause: In some regions of Scotland, stones can be susceptible to sulfate attack. Sulfates from the ground can react with the stone, causing it to weaken and crumble.

Solution: In extreme cases, it may be necessary to replace the stone with a more resistant type. Preventing moisture infiltration can also help mitigate sulfate attack.


Cause: Carbon dioxide from the atmosphere can react with the alkaline elements in stone, reducing its pH and leading to surface deterioration.

Solution: Applying breathable coatings can help protect against carbonation. Periodic monitoring and maintenance are also important.

Stone buildings in Scotland are not only a testament to the country’s rich history and architectural heritage but also a reflection of the challenges presented by the region’s climate. Common defects in stone buildings, including frost damage, erosion, biological growth, cracking, spalling, sulfate attack, and carbonation, can affect both the appearance and structural integrity of these structures. Identifying the causes and addressing these issues promptly through maintenance, repairs, and protective measures is essential to ensure the longevity and continued beauty of Scotland’s stone-built heritage. Preserving these structures is not only a testament to the past but a gift to future generations who will continue to admire and be inspired by these iconic buildings.

We are experts in this field and treat stonework with great care, attention and meticulous workmanship. This must be done to ensure any work undertaken doesn’t make the stone’s condition worse – as happens all too often with shoddy workmen.

When faced with the need to have stonework repair or cleaning carried out, choose a reliable, experienced and qualified company when it comes to stone repairs and cleaning. Otherwise you risk your valuable stonework becoming more damaged by under qualified “cowboy builders” who cut corners and do not apply the correct techniques.

Choose an expert in historic restoration stonework repair and cleaning – choose Balmore.

Contact us for a free chat and some advice about your property and stonework repair or restoration.