Now that Spring is here, pay close attention to the masonry features of your home. After this intense freeze and thaw cycle of the past winter, there may be structural, and non-structural masonry that needs repair and/or replacement. Did you ever wonder why so many solid masonry structures receive as much damage as they do during the winter in our region? Here is one typical condition; Frost Heave.
Frost heaving (or a frost heave) results from ice forming beneath the surface of soil during freezing conditions in the atmosphere. The ice grows in the direction of heat loss (vertically toward the surface), starting at the freezing front or boundary in the soil. It requires a water supply to keep feeding the ice crystal growth; and the growing ice is restrained by overlying soil, which applies a load that limits its vertical growth and promotes the formation of a lens-shaped area of ice within the soil. Yet the force of one or more growing ice lenses is sufficient to lift a layer of soil, as much as 30 cm or more. The soil through which water passes to feed the formation of ice lenses must be sufficiently porous to allow capillary action, yet not so porous as to break capillary continuity. Such soil is referred to as “frost susceptible.” The growth of ice lenses continually consumes the rising water at the freezing front. Differential frost heaving can crack pavements—contributing to springtime pothole formation—and damage building foundations.
Frost heave effects masonry above ground in walls, chimneys, parapets, brick and stone pointing, stucco facing, and any other masonry, especially porous, and soft stone, or areas already showing signs of distress.
Here are a few pictures of water damaged, frost heaved masonry.