The Forms of Moisture in Materials

2/12/2020 (Permalink)

Removing moisture and drying materials can prove to be a difficult project depending on how the moisture is held within the surface. Understanding the different types of moisture will allow you to remove it more efficiently. 

Surface Water

Surface water is the first type of moisture confronted during the drying process. This is the liquid moisture that sits on top of a material. This excess can be removed through various methods like extraction, mopping, wiping or pumping. After the removal process, all other remaining surface water can be easily dried by applying warm airflow to the material. Warm airflow applied directly to the material creates a quick and efficient evaporation process.

Free Water

Free water is moisture that has already absorbed into a material. This can happen when surfaces come in contact with water or are exposed to humidity in the air. Although this type of moisture is already absorbed into the material, it is still considered “free” water, as it has not chemically bonded with the material’s molecules. As airflow is applied to the material, free water begins to rise to the surface of the material and starts the  evaporation process. To create a faster evaporation process for free water, a higher temperature and a lower humidity ratio must be applied. 

Bound Water

Bound Water is moisture that has been absorbed into a material, such as wood, as has chemically bonded with the cells of that material. This is a much slower evaporation and drying process. First, the chemical bond has to be broken from the wet areas of a material. A warm airflow is usually not enough to create this reaction. However, heating the wet material can increase the rate of evaporation. Creating heat within the material forces bound water to release its chemical bond and pushes the water to the surface. 

Humidity, airflow and temperature are all important factors in the drying and evaporation process. Each of these aspects must be addressed depending on which type of moisture has come in contact with a surface or material. Knowing the differences between these types of moisture can better help you tackle these water damage issues.