Are your indoor mold levels higher than those outside?
Rate of Growth
Many factors influence mold growth. However, generally mold inside buildings can be dated back to when a moisture problem began.
On water damaged standard drywall, fast growing Stachybotrys chartarum takes five days to develop mold growth visible to the naked eye. Slower strains may take a week. So one can extrapolate from these optimum experimental test conditions that in the field, one may find mold growth appearing within a week of the initial water damage. OF course, temperature, mold type, moisture content, and other environmental factors play a part in increasing or decreasing the rate of growth.
For example, paperless anti-mold drywall is more condusive to your home's longeivity than the standard boards mold thrives on. A slow growing mold in winter will cause less damage than a fast growing mold in high summer humidity.
Antimicrobial compounds in building materials help to slow down mold growth.