A frost wall is a type of wall that adds no structural integrity to the building, but acts as an insulator. It is typical to see frost walls placed in basements since most basements are made of nothing more than cement and brick, which does not provide much insulation.
No matter what a home's basement is made from, a frost wall helps hold in heat. However, there are some types of basement walls that require more work to get them frost-wall ready. For example, basement walls that are made from cinder blocks require the homeowner to patch any open gaps in the mortar with brick filler. Basement walls that are made from poured concrete require the homeowner to patch any cracks with concrete sealer. Once the concrete sealer is applied, the next step is to apply a paint sealer, a specialty paint that helps prevent moisture from entering the basement. This is extremely important because the formation of moisture between the frost wall and the basement wall promotes mold growth.
Sometimes the term “frost wall” is used when referring to a layer of frost protection added to the foundation of a house. Just like a frost wall that is placed inside the house, a frost wall for the foundation of a house only works for heated structures. This type of frost wall holds heat from the structure in the ground to prevent freezing in areas where ground frost is common.