Click here to view a downloadable Mold Growth Timeline PDF.
The above infographic was taken from an archival Cleanfax article titled “How Long Does It Take Mold to Grow” by Richard Driscoll. In the article, Driscoll looks to several different studies on mold growth times. Driscoll’s goal, to try to establish whether the growth time generally considered accurate by restorers — 24-48 hours — is indeed correct.
Driscoll finds in perfect-condition lab testing microscopic mold appears at around 24 hours, though visible mold doesn’t appear until the three day mark. However, Driscoll’s review of research finds that in real-world situations the time required is much longer.
In his own experiment, Driscoll, who is an expert in water damage and mold remediation, soaks untreated drywall in a trough of water and finds that it takes seven days of being soaking wet before even microscopic growth begins to appear, a much longer window than previously thought.
Driscoll also looks into experiments by others in more true-to-life environments, which show still longer periods without growth.
In the article, Driscoll writes:
Everyone who is serious about moisture and mold should read both [“Controlled Study of Mold Growth and Cleaning Procedure on Treated and Untreated Wet Gypsum Wallboard in an Indoor Environment” by Michael Krause and Dr. Michael Berry’s study prepared for the Carpet and Rug Institute) and the references cited… You will find what Krause, Berry and other papers have proven is very interesting and goes totally against what most of us have accepted about the amount of time it takes for mold to colonize.