Controlling mold growth in buildings
To remove all mold spores from a building, or to have a building without finishes that promote mold growth, is simply not possible. The only way to truly prevent mold growth in a building is with careful management of humidity, condensation, and water intrusion via building envelope leaks, floods, or plumbing failures. For this reason, the risk of recurring mold growth must be addressed, not only by prompt repairs to address sources of water damage, but through a comprehensive mold and water damage management program. Key elements of a mold and water damage management plan are:
- Ongoing training facilities maintenance staff in the causes and how to identify indoor mold growth.
- Development and implementation of a surveillance program to ensure all instances of water/moisture infiltration are discovered and mitigated in a timely manner. This could include:
- Regular building inspections to examine the condition of interior finishes.
- Regular inspection of the interior and accessible HVAC components.
- Regular review of exterior envelope conditions to look for deterioration.
By regularly providing training for employees, they can become proficient in being able to see, hear, and smell potential problem areas that may require attention.
Building science and mold control
In general, the buildings envelope is a key line of defense for mitigating water and moisture infiltration into a building. General building envelope methodologies include the concept of providing both waterproofing and shedding water away from the building’s elements. The key building envelope concepts can be categorized into four components (can also be known as the 4D’s): deflection, drainage, durability, and drying. A properly designed, installed, and maintained envelope should be able to effectively deflect moisture from precipitation events, drain roof components efficiently away from the building, provide long-lasting materials and assemblies, and be implemented using three primary processes for drying. These processes include:
- Diffusion—movement of moisture through materials at the molecular level.
- Evaporation—conversion from liquid to a gas at the surface.
- Convection—transportation of moisture through
air currents.
Proper building envelope design must provide control layers which have water shedding surfaces, the design of building form and features to enhance drainage, employment of water-resistive barriers, continuous air barrier systems, thermal insulation, and vapor retarder/barriers. These concepts and designs must be effectively communicated; including effective details, drawings, specification, and construction review services; during the construction and/or restoration of buildings to ensure the continuity of building envelope concepts.
