Spalling: Finding Solutions for Deteriorating Masonry

Spalling is a common problem that affects masonry structures, leading to the flaking, chipping, or peeling of the surface layer. This deterioration can compromise the aesthetics and structural integrity of the masonry. Take, for instance the over century old Murney Tower Museum or the historic Inglewood at 100 Collingwood Street. Consulting with a professional masonry contractor ensures the implementation of proper techniques and materials for long-lasting results. In this blog post, we will explore the causes behind spalling and discuss effective solutions to address this issue.


Causes of Spalling:
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1. Moisture Infiltration: One of the primary culprits behind spalling is moisture infiltration. When water seeps into masonry, it can freeze and expand during freezing temperatures, exerting pressure on the masonry surface and causing it to crack and flake. Moisture infiltration can occur due to poor construction techniques, deteriorated mortar joints, or insufficient waterproofing measures.
2. Freeze-Thaw Cycles: Regions with significant temperature variations like Kingston, Ontario are particularly susceptible to spalling caused by freeze-thaw cycles. When moisture present within the brick freezes and expands, it places stress on the surrounding materials, leading to cracks and spalling. Over time, this process can worsen, causing further damage if left unaddressed.
3. Salt Crystallization: The presence of salts within masonry can exacerbate spalling. Salts can enter the masonry through various sources, such as groundwater or the use of deicing salts. When these salts crystallize, they exert pressure on the masonry, causing it to deteriorate and spall. This issue is commonly seen in coastal areas like Kingston, Ontario or buildings exposed to deicing salts.

Solutions for Spalling:

1. Identify the Source of Moisture: To effectively address spalling, it is crucial to identify and rectify the source of moisture infiltration. This may involve repairing damaged or deteriorated mortar joints, sealing cracks, improving drainage systems, or applying waterproofing coatings. By preventing water penetration, you can mitigate the risk of further spalling and deterioration.
2. Repair and Replace Damaged Masonry: For localized spalling, the damaged areas need to be repaired or replaced. This may involve removing loose or deteriorated material, preparing the surface, and applying suitable patching materials or new masonry units. Hiring a professional masonry contractor ensures that the repairs are executed with the necessary expertise and adherence to best practices.
3. Improve Drainage and Ventilation: Enhancing the drainage and ventilation around the masonry structure can help prevent moisture accumulation. This can include redirecting downspouts away from the masonry, installing weep holes, or improving the grading around the foundation. Adequate ventilation allows moisture to evaporate, reducing the likelihood of spalling.
4. Apply Protective Coatings: Applying a suitable protective coating or sealant can provide an additional barrier against moisture infiltration and salt crystallization. Various sealants are available, ranging from breathable coatings that allow moisture to escape to penetrating sealers that provide long-term protection.

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Case Study

When a homeowner in Alwington discovered unsightly flaking and crumbling brick on their century‑old limestone brick home, Masonry Kingston stepped in to restore both beauty and structural integrity. Alwington is one of Kingston’s oldest and most prestigious neighbourhoods, home values range between $800,000 and $1 million+ and these historic properties demand careful attention. The extent of spalling required us to address moisture infiltration, salt crystallization, and Kingston’s intense freeze–thaw cycles. We expertly removed compromised surface layers, repointed with breathable, compatible mortar, applied targeted waterproofing coatings, and improved drainage along the foundation. Leveraging our deep masonry experience, we prevented further deterioration and preserved the home’s heritage character.

The results were immediate and long-lasting: the homeowner now enjoys a fully restored façade free from flakes or stains, with restored structural resilience through Kingston’s wet springs and icy winters. Our preventative measures—like sealing mortar joints and installing effective moisture barriers—helped them avoid costly future repairs and maintain property value in a city that recently exceeded its 2023 housing targets and is projected to grow well beyond 200,000 residents by 2051 . Thanks to Masonry Kingston, this historic gem not only looks great but is protected for generations to come.

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