Remediation
Misting, drying and dehumidification during remediation
In plain English
Misting means spraying a fine water mist to keep dust down. R520 calls it controversial in mold work. Some practitioners use it routinely, but research cited in the guide suggests water-repellent spores can be knocked loose by the spray, and the added water can feed new growth. R520 says not to mist or fog disinfectants as a substitute for removal. Where misting is required, as in asbestos work, it calls for minimal water, pump sprayers rather than hoses, prompt pickup of runoff and humidity monitoring.
Drying and humidity control usually continue alongside removal. R520 describes conventional refrigerant dehumidifiers, which lose efficiency in cool air, low-grain refrigerant units that dry the air further, and desiccant units that keep working at low temperatures. Equipment used in contaminated areas must be cleaned afterward. Detailed drying practice is left to the IICRC S500 water damage standard.
There is a balance to keep. Strong negative pressure in a humid season can draw moist outdoor air into the structure and slow or reverse drying. Demolition can go on while drying continues, but R520 says the remaining materials must reach their drying goal before the remediation can be called complete.
Key points
- Misting is disputed and can release spores and add moisture.
- Never fog disinfectants instead of removing mold.
- Match the dehumidifier type to temperature and humidity conditions.
- Heavy negative pressure can pull humid outdoor air in.
- Materials must reach their drying goal before the job is complete.
Official text
This topic is covered in our own words because the standard behind it is copyrighted; we cite it below rather than reproduce it.
Citations
- IICRC S520 Reference Guide, IICRC S520 Standard and Reference Guide for Professional Mold Remediation — Reference Guide — Ch. 11, pp. 116–117. Best practice
- IICRC S520 Reference Guide, IICRC S520 Standard and Reference Guide for Professional Mold Remediation — Reference Guide — Ch. 11, p. 121. Best practice
- IICRC S520 Reference Guide, IICRC S520 Standard and Reference Guide for Professional Mold Remediation — Reference Guide — Ch. 5, pp. 58–59. Best practice