Lesson 9.1.1
Structural drying overview
- Inspect all potentially wet structural materials — walls, frames, skirting boards and so on. Pay special attention in older buildings: inspect for lead and asbestos, and follow local laws for removal, sampling and disposal of hazardous materials.
- Begin rapid drying immediately if moisture is detected. Remove and discard damaged or sagging materials promptly. Gypsum materials lose strength when wet but can recover if dried quickly.
- Evaluate walling materials and cavities for hidden moisture. Inspect sill plates on concrete floors — water can flow beneath and affect hidden areas. Watch for capillary action where moisture wicks up porous materials such as gypsum.
- Permeance is the ability of a material to allow water vapour transmission. Materials with low permeance, such as vinyl and enamel paint, may trap moisture and slow drying.
- Use warm, dry air to increase evaporation from within wall cavities. Combine evaporation and dehumidification for effective drying.