Mold spores range in size from about 2 to 100 microns with most being in the 2 to 20 micron range. To put this into perspective 1 inch = 25,400 microns. Mold spores are what germinate or grow actual mold once these get a water source. And it stands to reason that when mold first starts to grow you cannot see it with the naked eye.
Why this is important:
Mold spores are, for the most part, everywhere and originate outside. When a house is built many mold spores are trapped inside the walls. When water or moisture penetrates the wall then mold Will Grow!
Whether a person sees visible mold when the wall is open or not there will be mold because science says that within about 24 hours of getting water to these mold spores mold starts to grow.
The reason I emphatically point this out is because most people are not aware of this fact and if a wall is opened in your home for any reason mold spores will be released into the common air of that room and the home. In most situations this will not even be noticed except some of the symptoms of exposure to excess mold spores or the wrong type of mold spores depending on the immune system of the person being exposed. This can range from no noticeable symptoms to mild allergic reactions and even to extreme health symptoms that can make breathing more difficult and more.
In a recent inspection moisture was found in the ceiling and walls of a home as a result of a air conditioning condensation line leaking for an unknown period of time but likely several weeks. When the company removed the wet drywall of the affected areas no Visible Mold was found and informed the owner of such. However, this was misleading since when air samples were taken in the area (under containment) there was an excessive amount of mold spores in the area, specifically Aspergillis/penicillium in the 8,000 count range. This happened because the company performing the remediation work did not seal the opened wall cavities which allowed 'extra' mold spores to enter the contained area and eventually the home when a containment breach occurred by accident. Subsequently more work had to be done.
So please keep in mind, especially if you have health concerns or conditions, that when walls are opened for any reason you can be exposed to excess mold spores for this reason and you should take precautions. Downloading my Special Report on this site at
http://www.ocmolddetection.com/landing.html will help you to know what precautions to take.