Water Absorption - What Is It?

Water absorption is a parameter of building materials defined by the water absorption coefficient "w".

This coefficient "w" (measured in kg/m²) indicates the amount of water absorbed by a material's surface during the first hour of exposure to moisture.

Classification of Materials by Water Absorption:

• Non-absorbent materials: w < 0.5
• Absorbent materials: w < 2.0
• Impermeable materials: w < 0.1