Freeze damage occurs in brick because of a combination of excessively wet brick and freezing temperature. A number of conditions have been cited as contributing to the potential for damage, such as under-firing of the brick, a rapid freeze/thaw cycle, and impurities in the pore structure of the brick creating excess large pores for entry of moisture. 

    Brick wall fences are especially prone to freeze damage because of their sides and top are all exposed to rain and extreme cold. The tops of brick fences often suffer the worst damage because of radiant heat loss into the night sky.

    As the number of voids in the brick increases, so does its ability to absorb and hold water, sucking it in through capillary action. Since water expands in volume by about 10% at freezing, the result is fractures in surface like in the photo above. The mortar joints were repointed after the brick damage, so it’s likely they suffered damage too. 

    Here’s another example of freeze fractures in the sill course of an Ocala Block home in Gainesville.

    Rising damp is a problem that also causes brick surface deterioration. Go to our blog post What causes the surface of old bricks to erode away into sandy powder? to learn more about it. Also, see our blog post What would cause long horizontal lines of brick mortar to fall out? for yet another defect caused by moisture penetration of a brick wall. 

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To learn more about exterior walls and structures, see these other blog posts:

• What are the pros and cons of concrete block versus wood frame construction?

• Should I buy a house with a crawl space? 

• Why is my stucco cracking?

• There's cracks running along the home's concrete tie beam. What's wrong? 

• How do I recognize serious structural problems in a house?

• What is engineered wood siding?

• Should I buy a house that has had foundation repair? 

• What is a "continuous load path”?

• Should I buy a house with asbestos siding?   

• How can I tell if cracks in the garage floor are a problem or not? 

• What do you look for when inspecting vinyl siding?

• Why is housewrap installed on exterior walls under the siding? 

• How do I recognize serious structural problems in a house?

• Why did so many concrete block homes collapse in Mexico Beach during Hurricane Michael? 

• How can I tell if the concrete block walls of my house have vertical steel and concrete reinforcement?

• Should I buy a house with structural problems? 

• How can I tell whether my house foundation problems are caused by a sinkhole or expansive clay soil?

        Visit our EXTERIOR WALLS AND STRUCTURE page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.