Case Study: Ventilation fix and mold treatment eliminated 25,000 spores

A homeowner contacted Claro about testing their daughter's home after discovering a bathroom leak and suspecting moisture and mold issues throughout.

The inspection revealed multiple moisture problems: visible mold in the main bathroom, ventilation issues, an attic extractor hose going nowhere, and a significant leak from the bathroom above affecting the garage. The soaked garage floor and 100% wet rear wall indicated severe water intrusion requiring immediate attention.

Testing the master bathroom showed a MoldSCORE of 140 with 920 spores per cubic meter. Visible mold was growing on the corner above the shower, indicating moisture accumulation in that area.

The garage registered catastrophic contamination: an Overall MoldSCORE of 300 (maximum severity) with 25,000 spores per cubic meter. The soaked floor and completely wet rear wall from the bathroom leak above had created severe moisture conditions and mold growth.

The inspection confirmed the problem: the main bathroom's ventilation extractor was inadequate, unable to properly manage moisture from shower use. The attic extractor hose was disconnected and going nowhere—not properly venting moisture out of the home. These combined issues caused moisture to migrate through the home and leak into the garage below, creating the 25,000 spore environment.

The daughter and any occupants of the home were breathing contaminated air in both the master bathroom (920 spores) and throughout the home, with the garage representing severe water damage contamination.

Claro's comprehensive treatment addressed both the moisture sources and the contamination. The bathroom ventilation was corrected. The attic extractor hose was properly configured to vent outside. The garage leak source from the bathroom above was identified and repaired. Wet materials in the garage were addressed, and the area was treated to eliminate the catastrophic mold growth.

Post-treatment testing confirmed complete elimination of contamination. The master bathroom dropped to less than 13 CFU/m³—from 920 spores to undetectable. The garage dropped to less than 13 CFU/m³—from 25,000 spores to clean.

The occupants could finally use the home without breathing contaminated air. The moisture control issues were resolved through proper ventilation and leak repair, preventing future recurrence.

This case demonstrates why bathroom ventilation problems create whole-home moisture issues. The inadequate extractor and disconnected attic hose allowed moisture to accumulate and migrate, creating both bathroom mold (920 spores) and catastrophic garage contamination (25,000 spores). Professional assessment of ventilation, leak repair, and comprehensive treatment eliminated the contamination and protected the home's occupants.