How does moisture move through hygroscopic materials?

Moisture moves through hygroscopic materials through two primary mechanisms: capillary action and diffusion. Hygroscopic materials are those that can absorb moisture from the environment.

Capillary action involves the movement of liquid water within the pores of a material. This occurs due to the adhesive and cohesive properties of water, which allow it to rise or move in tiny spaces against gravity, particularly in porous materials like wood, textiles, or certain building materials. This movement as a liquid is essential for understanding how dampness can spread through these materials during water damage situations.

On the other hand, moisture can also move in the form of water vapor. This process is known as diffusion, where water vapor travels from areas of high humidity to areas of lower humidity. This is especially important in drying scenarios, as moisture from the wet zone will migrate toward dryer areas to equalize moisture levels due to the principle of vapor pressure differences.

Since hygroscopic materials can facilitate both types of moisture movement, the ability to transfer moisture as a liquid and as vapor is critical in restoration and remediation practices, making the understanding of these concepts fundamental for professionals in the field.