Commercial Building Remediation

A multi-tenant commercial building with complaints of musty odor on the lower level and staff reporting headaches.

About the project

A three-tenant commercial building near downtown Manitowoc. The property manager called after two separate tenants reported musty odor on the lower level and three staff members complained of headaches that resolved on weekends.

The building had a partially finished lower level used for storage and one tenant's back office, plus a mechanical room housing the shared HVAC equipment.

The challenge

Air sampling in the back office returned Penicillium/Aspergillus counts roughly six times the outdoor control. The visible growth in the storage area — a modest patch on one wall — was nowhere near enough to account for that.

The source turned out to be the mechanical room. A condensate line from the air handler had been dripping into a floor cavity for long enough to establish growth under the housekeeping pad, and the return air plenum was drawing directly from that room. The system was distributing spores to all three tenancies.

The result

We worked three consecutive nights so no tenant lost a business day. Containment went up around the mechanical room and the affected storage wall, the floor cavity was opened, remediated and dried, and the condensate line was rerouted and correctly trapped.

The HVAC system was cleaned — coils, plenum and accessible duct — and the return was sealed and relocated. We re-tested all three tenancies afterwards.

Post-remediation counts in the previously affected office came back at 40% of the outdoor control. The headaches stopped. The property manager now has us on an annual moisture inspection for their whole portfolio.

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