How Long Does It Take For Black Mold To Grow After Water Damage. How long after a flood does mold grow? After a flood in your home or business, a mold colony can establish itself within 24 to 48 hours, and once a colony has been established, it can never be completely eradicated.
Your air conditioning drip pans must be kept clean, and your drain lines must be kept clear. After 24 hours, your mold spores are likely to be germinating on your surfaces, but this can take up to 3 days. Under the right conditions, mold can begin to grow and spread in a matter of 24 to 48 hours.
The generally accepted theory is within 24 to 48 hours after a surface has become wet.
The generally accepted theory is within 24 to 48 hours after a surface has become wet. However, it will take two weeks or more to become visible on untreated drywall according to experiments by krause. How long does it take mold to form after water damage? Even worse, it will continue to grow until steps are taken to eliminate the source of moisture, and effectively deal with the mold problem.