Purewood Structural Panels, a hygroscopic building material
Hygroscopic building materials can absorb and release moisture from the air, or liquids. When hygroscopic materials are used in buildings, a moisture equilibrium is reached. Solid wood, wood fibre insulation materials, clay, hemp, flax, and cotton are examples of hygroscopic materials.
One cubic meter of wood, for example, has the ability to absorb approximately 150kg of water in the form of vapour, without compromising thermal insulation properties and dimensional stability. Depending on building size, a solid wooden house made by Pacific Timberworks can contain between 65 and 150 cbm of solid wood, wood fibre insulation and manufactured wood products.