Case Study 09027: Mold Problems in Split Level House
Facts/History:
-Split level, single family house, early 1970’s construction
-History of water problems into the lower level
-Two forced hot air/central air conditioning system
-Central humidifier on one of the heating systems
-Fully carpeted—upper and lower levels
-Tenants have concerns about mold—people living in the house, including a young child, have had chronic illnesses since moving in less than a year ago.
Observations:
-Mold odor throughout the home but stronger in the lower level
-Visible mold on Sheetrock walls at the floor level in several areas
-Visible mold and rotting materials beneath the lower level stairs (storage crawlspace beneath front steps leading into house)
-Carpeting in lower level was full of dust and dirt
Sampling Strategy:
-Air sampling to identify mold types and levels throughout the house
-Surface sampling to identify mold types and their extent on building materials and inside the HVAC system
Lab Results:
-Air samples showed elevated mold levels in the lower level (Penicillium was the main mold)
-Basement mold spores have been migrating to the upper level through HVAC ductwork and the open stairwell
-Indoor mold levels higher than outdoors and different mold types found inside
-Mold growth was confirmed on the following surfaces:
Recommendations:
-Professional mold remediation to remove contaminated building materials in the lower level, including carpeting, Sheetrock, rotten wood materials, and more
-Professional HVAC cleaning, system maintenance, and upgrade
– Specialized whole house cleaning
-Identifying and resolving water issues
-Dehumidification in the lower level
-Additional GML recommendations to help prevent mold growth in the lower level