The general rule is that when mold is visible, it is time to kill it and remove it. But mold isnt always visible and so there are other criteria to strongly consider when it comes to mold remediation. Here are the four criteria to look for mold in your home.
1. A water event or occasional/frequent water intrusion
Has there been recent water intrusion? Water does not necessarily equal mold growth as spores have to already be present. But since mold spores are microscopic (2-10 microns), a water event is usually the trigger that causes mold to be seen or otherwise detected.
Note: Mold means moisture or humidity is, or has been present. Water does not necessarily mean mold growth is present.
Most molds cause the organic material the mold is consuming to change colors. Whether the food source for the mold is human food or drywall paper, if colonization is allowed for enough time, there will usually be a discoloration that will reveal a mold problem.
Most molds, when allowed to grow in abundance, are visibly seen in certain colors. Mold is not only black. Many species are visible in gray, white, brown, red and even some hues of pastel colors. Some molds look like dust, or fuzz, while others look like sand granules. Certain molds thrive on certain food sources, and they all require different moisture content or relative humidity in the ambient air.
Note: Water seeping through masonry sometimes causes a white crystalline, powder-like discoloration called efflorescence. This substance is made up of minerals and should not be confused with mold.