Mold Contamination

More than one area of a building may be affected by mold growth; in those instances, it is important to treat contaminated areas simultaneously or in rapid succession to avoid recontaminating remediated areas. Air is transferred from one area of a building to another through various exchanges. Mold spore travel through the air of those exchanges, which is why we recommend treating all of the affected areas without delay.

The EPA provides a good description of air transfer stack effect on pages 9 and 10.