At the Safe Housing Collaborative conference in Austin, Texas, this October, speakers described what real remediation demands: containment under negative air pressure, careful moisture work, and instruments that find water and mold behind finished walls. Those sessions stand in sharp contrast to what many tenants see in their own apartments. This article describes the shortcuts I encounter most often and how the published standards treat each one.
Proper mold remediation costs money and takes time, and some landlords look for a faster, cheaper answer. The shortcuts they choose often hide the mold for a few weeks while the growth continues inside the walls. Meanwhile, the tenants keep breathing the spores, and the illness that brings many of them to my office continues to build.
Since July 1, 2025, the Maryland Tenant Mold Protection Act, Real Property Article § 8-220, has required landlords to assess reported mold within 15 days of a tenant’s written notice. The landlord must then remediate within 45 days of the assessment, or within a reasonable time when the work cannot finish sooner. The Act also requires that the assessment and remediation follow industry practices, which makes the published standards the measure of a landlord’s conduct.
The principal remediation standard is the ANSI/IICRC S520 Standard for Professional Mold Remediation, Fourth Edition (2024), from the Institute of Inspection, Cleaning and Restoration Certification (IICRC). The United States Environmental Protection Agency (EPA) publishes Mold Remediation in Schools and Commercial Buildings and A Brief Guide to Mold, Moisture, and Your Home. The World Health Organization (WHO) issued Guidelines for Indoor Air Quality: Dampness and Mould in 2009, and the American Industrial Hygiene Association (AIHA) adds Recognition, Evaluation, and Control of Indoor Mold, which industrial hygienists call the Green Book.
Most mold cases begin with something small: a drip under a sink, a stained ceiling tile, a window that weeps in every storm, or a soft spot in the floor beside the tub. The EPA’s Brief Guide advises drying water-damaged areas and items within 24 to 48 hours to prevent mold growth. Measured against that standard, a landlord who lets a reported leak sit for weeks has already fallen short.
The WHO treats the prevention of persistent dampness as the most important protection against the health effects of damp buildings. A minor leak that a landlord finds, repairs, and dries within two days seldom grows into a mold problem. The same leak left for weeks or months gives mold the time it needs, and the landlord’s delay, more than the leak itself, often becomes the heart of the case.
Many landlords send a maintenance worker or the remediation contractor to look at the problem, with no testing and no written report. Without an assessment, nobody knows how far the growth extends, which materials it has reached, or what the air in the home contains. When the remediator sizes up the job and also profits from the work, no impartial professional checks the scope.
Mold needs moisture, and every authority on the subject starts there. The EPA warns that if someone cleans up the mold but fails to fix the water problem, the mold will most likely return. A landlord who wipes the visible growth while the roof, plumbing, window, or ventilation problem continues has simply reset the clock.
Painting a stained ceiling or wall removes the problem from view and nothing more. The EPA tells property owners not to paint or caulk moldy surfaces, but to clean and dry them first, and notes that paint applied over mold is likely to peel. Mold-resistant paint applied over active growth cannot remove the colony already living inside the drywall beneath it.
Bleach remains the most popular home remedy, and it fails on the materials where mold usually grows. Bleach can kill surface mold on tile, glass, and metal, but it cannot reach growth embedded in drywall, wood, and carpet. The EPA’s guidance calls for scrubbing hard surfaces with detergent and water and for removing the porous materials that mold has colonized.
Ozone machines carry bold marketing claims, often with an EPA establishment number printed on the box. That number identifies only the factory that made the machine; it signals no EPA approval. Research shows that ozone at levels people can safely breathe does not kill mold, and the concentrations needed to affect mold pose immediate health risks. Ozone also cannot penetrate the porous materials where the growth lives.
Some contractors fog a unit with an antimicrobial mist or spray a coating over moldy framing and call the job done. The S520 standard does not accept encapsulation as a substitute for removing contamination, and it places antimicrobials and coatings after physical removal and cleaning. Fogging leaves mold fragments in place, and the EPA cautions that even dead mold can still cause allergic reactions in some people.
Removing moldy drywall in an open apartment releases enormous numbers of spores into the air. Without plastic barriers and negative air machines exhausting through high efficiency particulate air (HEPA) filters, those spores settle on furniture, clothing, bedding, and ductwork throughout the home. Tenants who stay in the unit during uncontained demolition can suffer a heavier exposure from the repair than from the original problem.
A proper job ends with post-remediation verification, in which an independent assessor inspects the area and repeats air and surface sampling before the containment comes down. Many landlords skip that step or let the remediator grade its own work. The IICRC standard expects an assessor who lacks independence from the remediator to disclose that conflict in writing, and tenants should ask for the clearance report by name.
The Act requires landlords to communicate with occupants during the assessment and remediation. Landlords who send crews without notice, refuse to share test results, or ignore questions about whether the family should stay elsewhere fall short of that duty. Silence also deprives tenants of the information they need to protect their health and their belongings.
Tenants should report every leak and every sign of mold in writing, keep a copy, and keep a dated list of every complaint and every visit. The date of that first report starts the 24 to 48 hour measure, so it matters. Photographs of the growth, the water damage, and the work as it proceeds create a record that no one can dispute later. Tenants should also ask for the assessment report, the remediation protocol, and the clearance results.
A tenant who doubts the landlord’s response can arrange independent testing, before or after the landlord’s work, by an assessor who answers to the tenant. Rent escrow in the District Court addresses the condition itself, though it does not compensate anyone for illness. If new symptoms develop after exposure to mold or water-damaged building materials, including exposure you did not realize at the time, you should see a doctor.
Christopher L. Beard, an Annapolis attorney, concentrates his practice in toxic mold injury and habitability claims for Maryland tenants. If you have questions about mold in your home, e-mail chris@attorneybeard.com or call (410) 267-0227. You can also read our article on the Maryland Tenant Mold Protection Act.
To see what a proper job looks like from start to finish, read Tools of the Trade: How Mold Assessors and Remediators Should Handle a Moldy Home. You can also return to the attorneybeard.com home page.
