| Hygroscopic Building Materials: |
Building materials which have a natural affinity to hold and retain water and moisture vapour, especially building materials when indoor humidity exceeds 70% for periods of time. Restorative Drying Note: a) Building materials, such as blown acoustic ceilings and acoustic tiles, drywall and wall insulation, which attract, readily absorb, and take up water and moisture vapour. b) Once saturated, hygroscopic building materials will not release their water and moisture vapour as fast as they retained it. c) Hygroscopic building materials when wet or damp, are typically those materials that aid in the distribution of spores. See Bound Water, Moisture Content, Moisture Vapour |