Protect your home from frost heave damage

Freezing temperatures can cause a number of heartaches for homeowners, ranging from winter heating costs to burst pipes. They can also lead to a problem you may not notice until the spring: damage caused by frost heaves.

Frost heaves occur when water in the soil freezes, causing it to expand and put pressure on parts of your home. Debra Judge Silber, writing for Fine Homebuilding, says that not only will ice crystals expand, but capillary action and vapor diffusion will draw more water up into the frigid zone. This moisture freezes into ice lenses, which put upward pressure on the soil and anything built into it.

This movement of soil can affect your home in a number of ways. Polli Construction, a company in South Burlington, Vt., says frost heaves may put enough pressure on your home to cause cracks to form in the walls. You may notice that your doors and windows are sticking. Frost heaves can also damage your foundation, cause bulges or cracks to form in your driveway, or push up on pilings enough to warp a deck.

The spring thaw can exacerbate the problem. Silber says that once the ice lenses melt, structural components will sink back into the soft soil and may be misaligned.

Some types of soil are more prone to frost heaves than others. Polli Construction says clay soils are most vulnerable to freezing due to their higher moisture content. Erie Insurance, a company in Erie, Pa., says loamy and silty soils also tend to freeze during the winter. Sandy soils are less likely to develop frost heaves, but can still freeze if the water table rises high enough.

Structures built in areas with cold winters usually extend deep enough into the soil to avoid frost damage. Mark Wallace, writing for the concrete industry resource Concrete Construction, says heated buildings are also less likely to be affected by frost heaves since some heat is lost to the soil around them.

If you are experiencing problems caused by frost heaves, you might need to strengthen your foundation. Erie Insurance says helical piers and wall anchors may be necessary to reinforce the foundation and bear the weight of the home.

Polli Construction says a good foundation will have a sturdy footing at least twice as wide as the walls it is supporting, along with rebar to keep the wall intact in case of cracking. It should also extend farther below the surface than freezing temperatures are likely to penetrate.

One effective way to keep frost heaves from forming is to ensure that the soil around your home is not retaining too much water. There should be a sufficient slope away from the foundation to let water run off, and downspouts should also discharge water away from the home. Some residences may benefit from a drainage system around the perimeter of the foundation.

Driveways, patios, and deck pilings are more likely than foundations to suffer frost heave damage, since they are unlikely to have nearby heat sources that can keep moisture from freezing near them. Reuben Saltzman, a Minnesota home inspector writing for the real estate community ActiveRain, says pilings tend to use concrete footings to prevent this problem. However, these footings can still be dislodged if freezing water and soil are able to adhere to it.

Bell-shaped footings are more capable of resisting pressure from frost heaves, but can also break if they are put under too much strain. Sleeves or insulation can help keep the pilings from being gripped by frost heaves. Silber says you can also use gravel to backfill around a footing to improve drainage.

To minimize the chances of frost heave damage to driveways and patios, you can consider a capillary break. This mechanism will prevent more water from being absorbed into the freezing area of the soil, thus reducing the severity of the frost heaves.

Another option to combat frost heaves is to modify or even replace the soil. Erie Insurance says polymers can be injected into the soil to stabilize it and keep it from getting too saturated. You can also replace the soil with a type that is less likely to develop frost heaves.

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