Comment l'infiltration d'humidité contribue-t-elle aux ventres-de-bœuf dans les murs en maçonnerie?
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How does moisture infiltration contribute to frost boils in masonry walls?

Understanding the Impact of Moisture Infiltration on Frost Boils in Masonry Construction

The role of moisture in masonry walls

Moisture infiltration is a common issue in masonry walls, as water can seep through porous materials like brick and stone. This can lead to a variety of problems, such as mold growth, efflorescence, and structural damage. One particular issue caused by moisture infiltration is the formation of frost boils.

What are frost boils?

Frost boils, also known as "swellings" or "bulges," are deformations that occur in masonry walls when moisture trapped within the wall freezes and expands. This expansion can cause the siding to separate from the structure, leading to the visible bulges that characterize frost boils.

How moisture infiltration leads to frost boils

Moisture infiltration in masonry walls can result from various factors, including poor construction techniques, inadequate waterproofing, or compromised sealants. When moisture penetrates the wall, it becomes trapped inside the masonry materials. As temperatures drop, this trapped moisture freezes and expands, putting pressure on the surrounding materials and causing frost boils to form.

The freeze-thaw cycle

The freeze-thaw cycle plays a crucial role in the formation of frost boils. When water freezes, it expands by approximately 9%, exerting significant pressure on the masonry materials. This pressure can cause the materials to crack, break, or dislodge, further exacerbating the issue. Repeated freeze-thaw cycles can lead to more significant damage, ultimately resulting in structural problems.

Preventing moisture infiltration and frost boils in masonry walls

Preventing moisture infiltration is essential to avoid frost boils and other issues in masonry walls. Some steps to help prevent moisture infiltration include:

  • Proper construction techniques: Ensuring that masonry walls are constructed with adequate drainage and flashing systems can help prevent moisture infiltration.
  • Waterproofing treatments: Applying waterproofing treatments to the exterior surface of the wall can help repel water and prevent it from penetrating the masonry materials.
  • Maintenance and repairs: Regularly inspecting masonry walls and addressing any issues, such as cracks, deteriorating mortar, or compromised sealants, can help prevent moisture infiltration and the formation of frost boils.

Seeking professional help

If you suspect that your masonry walls are suffering from moisture infiltration and frost boils, it's essential to consult a professional masonry contractor like Maçonnerie Montréal. Our team of experts can assess your walls, identify any issues, and provide appropriate solutions to repair and prevent further damage.


In conclusion, moisture infiltration plays a significant role in the formation of frost boils in masonry walls, as trapped water expands when it freezes, leading to bulging and potential structural damage. Preventing moisture infiltration and addressing existing issues are crucial steps in maintaining the integrity of masonry walls.