This past winter was the second wettest in two decades, and all of this rain resulted in myriad mold problems for Bay Area homeowners. Even though the calls for rain-related problems started “drying up” a couple of months ago, the problems created by all of this rain have persisted.
The owners of this home in San Mateo County noticed that their crawl space was flooded with water following a particularly heavy period of rain, and they contacted their contractor who then installed a sump pump system to deal with the standing water. Once this standing water was addressed, the homeowners thought that they were good to go, but the soil in the crawl space stayed damp for weeks, even though the sump pump was removing the standing water. This dampness can spike the humidity, and this elevated humidity can lead directly to mold spore growth.
The mold depicted in this photo is growing on the back side of a standard sheet of 1/2″ drywall. The stud bay had been filled with R13 batt insulation, but this didn’t prevent the growth of mold on the drywall itself. Once mold has grown into the paper on drywall (on either side), the drywall needs to be removed and discarded.
So this case is another reminder that moisture issues need to be addressed immediately following any water intrusion event, and this includes drying out the area with commercial dehumidifiers and fans. Mold spores will start to germinate within 24 to 48 hours of being exposed to water, so homeowners need to call in the professionals immediately upon discovery of any water issues. Any delays can (very likely will) lead to mold growth, so don’t wait, make that call!