How Multifamily Operators Can Keep Mold From Becoming a Major Liability
Prompt action and clear protocols can protect residents and reduce property risk.
In October 2025, the District of Columbia won a $41 million judgment against the former owners of Marbury Plaza, a 2,500-resident complex in Ward 8, after alleging mold in 96 percent of its apartments, along with chronic leaks and failing building systems. It was the largest housing-conditions judgment ever against a D.C. property owner.
Marbury Plaza is extreme. After nearly 35 years in property management and as an expert witness in mold disputes, I have seen large liabilities grow from small, ordinary failures. The key question is rarely whether mold was present. It’s what management knew, when it knew it, what it did and whether it can prove it.
The warning signs operators overlook
Mold needs spores, which are nearly everywhere; nutrients, such as drywall, wood and dust; and moisture. Moisture is the only condition operators can control, and growth takes off once relative humidity reaches about 60 percent.
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The sources of serious claims are ordinary: slow leaks under sinks, clogged HVAC condensate lines, failed window seals, envelope leaks, nonworking bathroom exhaust fans and vacant units with the HVAC off. Musty odors can signal active growth even when nothing is visible and visible growth can mean more growth behind the wall.
Watch the work order history, too. Repeat requests in the same unit or stack, complaints that return after a “fix,” and tickets closed without an identified water source are all red flags. Dry wet materials within 48 hours. A leak that waits days for a vendor can turn a drying job into a remediation project.
What to do when a resident reports mold
Respond promptly and in writing. Acknowledge the report the same day and schedule an inspection. Timelines are increasingly set by law: Maryland’s Tenant Mold Protection Act, signed in 2025, requires an assessment within 15 days of a tenant’s written notice and remediation within 45 days or another reasonable time frame.
Inspect for the water source, not just the stain. A thorough visual inspection, with moisture readings and photos, is usually enough. Sampling is not required before remediation. If there is mold or water damage, fix it.
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Never paint over it. In Sales v. Kecoughtan Housing Co. (2010), a tenant alleged that staff painted over mold that continued to spread and the Supreme Court of Virginia allowed her negligent-repair claim to proceed. Once management undertakes a repair, it must use reasonable care: correct the moisture source, properly remove or clean affected materials and confirm that water infiltration has stopped. Trained staff can often handle small, isolated areas with proper containment. Larger or hidden growth requires qualified professionals and hiring one doesn’t end management’s responsibility to oversee scope, containment and records.
Don’t diagnose, dismiss or concede. In Cornell v. 360 W. 51st St. Realty (2014), New York’s highest court found a tenant’s evidence linking her illness to mold insufficient. The lesson isn’t that mold can’t make people sick. It’s that staff should fix the condition, preserve evidence, communicate respectfully and leave medical and legal questions to professionals.
Investigate before assigning blame. Residents and owners share responsibility and Virginia law provides a defense if mold results solely from tenant negligence. Blocked exhaust fans or indoor laundry drying can create moisture. However, that conclusion must be based on documented readings and the confirmed absence of a building leak, not on assumption.
Why documentation matters
Here’s a scenario I use in training. A manager dispatched maintenance and a restoration vendor promptly after every complaint. Months later, staff remembers drying and cleaning the unit, but the work orders say only “treated,” and the vendor file has no moisture map, photos, scope or closeout. Management says, “We responded every time.” What a jury hears is a disputed memory, not proof.
The test is whether an independent reviewer could reconstruct the entire response from the file alone. That means recording the initial report, every communication, inspection photos and moisture readings, the identified source, decisions and their reasons, and access attempts. The report should also include vendor qualifications and scopes. Post-remediation verification should show that the area is visibly free of mold, has normal moisture readings and the source has been fixed, ideally with confirmation from an independent assessor or industrial hygienist. Keep every entry factual and neutral. Emails and work order notes can become exhibits.
Building a proactive mold management program
The strongest position is a written, site-specific operations and maintenance plan for mold and moisture control. It should assign roles to corporate, site managers, maintenance staff and residents. It should also establish response procedures for water intrusion, service requests and remediation and schedule preventive inspections of HVAC, plumbing and the building envelope.
Training makes the plan real. Maintenance teams need to locate moisture sources and handle small cleanups safely. Leasing staff need to know how to take a report and what not to say. Supporting tools, such as an incident response flowchart, a water intrusion log and a resident tip sheet on preventing moisture, keep responses consistent. Since different states impose their own requirements, plans should reflect local law and should be updated after every significant incident.
No operator can guarantee a property will never have mold. Every operator can commit to a prompt, source-focused, well-documented response every time. That consistency protects residents and the asset and, if a claim comes, helps the property team prove that it met the standard of care.
K. David Meit, CPM®, is the founder & principal of Oculus Realty, LLC, and Oculus Expert Witness. He has more than 35 years of experience managing multifamily, mixed-use and retail properties and is a licensed real estate broker in Virginia, Maryland and D.C. He provides impartial expert testimony for both plaintiffs and defendants on property management standard of care and premises liability.
