What Does Frost Inside of a Concrete Foundation Mean?

Concrete Construction

• Concrete is a mixture of cement, aggregate and water that is poured or formed into shapes for a number of construction uses. Foundations are generally made of concrete, either poured into forms for walls or laid in block like other types of masonry. Concrete generally contain 15 to 20 percent water, according to the PortlandCementAssociation website. The water and cement in the concrete mix must undergo a process called hydration, during which crystals form within the materials to cure and harden it. Extreme temperatures can affect the rate of hydration and the proper curing of the concrete material for the foundation of the home.

Causes of Frost Damage to Concrete

• Concrete must be properly set before freezing weather arrives or the water within the mixture will freeze, expanding the material as much as 9 percent, according to the WalkerConcrete website. Scaling, cracking and heaving of concrete from the ground can occur. De-icing salts can increase this rate of expansion to as much as double the amount, creating even more stresses within the concrete. Subsequent thawing then releases the pressure and the water crystals within the concrete melt. The components within the concrete shift and crack. Newly set concrete is particularly vulnerable to these freeze-and-thaw cycles. Improper mixtures of concrete can also cause increased problems with frost within the concrete when cold weather arrives.

Preventing Frost Damage to Concrete

• To prevent problems from frost in concrete and the resulting freeze-and-thaw pressures, ensure that you use the right percentage of ingredients. Using less water increases the strength of concrete and reduces frost cracking and heaving. Avoid pouring concrete foundations in temperature extremes. The best temperature for pouring concrete is around 55 degrees Fahrenheit, according to home improvement expert Tim Carter of the AskTheBuilder web site. If you must pour the foundation in lower temperatures, it should be immediately protected with plastic, straw or other insulating materials.

Installing Frost-Proof Foundations

• Additives are sometimes added to concrete to assist in rapid curing and to prevent problems with freeze-and-thaw cycles that can damage the internal structure of the materials. Sealing products may also be added to the surface to prevent saturation of the concrete with water that can lead to frost and cracking problems.