Observing mold growth may not be the most robust trigger for action; the observation of water incursion or the occurrence of prolonged humid conditions in a building are the precursors for potential problems. Early action can frequently prevent a sequence of events that can delay or otherwise jeopardize the success of a construction project. If a water incursion event occurs, such as partial flooding of a building from an open roof drain rainleader, a timely response to dry water-impacted soft building materials before mold begins to grow may be all that is necessary. In some cases, effective and timely drying of wet building materials will require removal of installed materials such as drywall panels or carpeting. If soft building materials remain soaking wet for a few days, or the complete drying process requires weeks instead of days, mold will begin to colonize and concerns about possible health impacts may surface.

If mold is observed by staining on building materials, the water incursion mechanism that allowed the mold to grow should be identified and resolved. Wet materials should be dried or removed. Depending on the location, extent and nature of the mold, as well as the occupancy status of the building, mold-impacted building material such as drywall, may require removal. In these cases, a knowledgeable and Board Certified Industrial Hygienist (CIH) should be consulted to evaluate the site condition and determine what, if any, action is necessary to complete the response. As general rule of thumb, limited and localized mold-impacted building materials may be treated or removed as a normal housekeeping chore; larger quantities of mold impacted materials in several locations of a building may require special precautions to limit further building damage and insure a healthful work environment. In all cases, ignoring a water incursion or mold related problem is a formula for a costly and unnecessary crisis the effect of which can linger for an extended period of time.