Ann Arbor averages 36 inches of precipitation annually and exceeds 80 percent relative humidity on 60 or more days per year. Lake-effect moisture and cold winters drive condensation against uninsulated walls in the city large pre-1970 housing stock, including dense student-rental neighborhoods near the University of Michigan where deferred maintenance compounds risk. Mold doubles in affected area within days.
Basement flooding along the Huron River corridor is well-documented; FEMA Zone AE properties flooded in 1968, 2002, and 2014. Attic condensation in 1940s to 1960s bungalows and ice dam damage forcing melt water into wall cavities are also widespread, and structures not professionally dried after flooding develop chronic mold inside framing.
Michigan has no separate mold license. Require the IICRC Applied Microbial Remediation Technician (AMRT) credential, pollution liability insurance, and post-remediation clearance testing by an independent industrial hygienist. Call 24/7 for certified assessment now.