Mold is like gluten: some people are more sensitive to it than others.

But who’s responsible for testing for mold and getting rid of it, renters or landlords? The answer depends on the severity of the mold and the cause of the problem.

It’s easy to assume an extensive remediation project would be expensive and unnecessary. But that’s not always the case. A failure to respond to a genuinely hazardous mold condition could result in significant discomfort and health problems for renters who are sensitive or allergic to mold. And it could result in a lawsuit.

Mold can also cause permanent damage to rental units. So it’s best for landlords and renters to communicate with each other about any potential issues related to mold, and start with the necessary inspections.

Common types of mold in homes and apartments

According to the Centers for Disease Control and Prevention, as many as 300,000 varieties of mold exist on our planet, and many are benign. However, sensitive individuals can experience respiratory irritation, aggravated asthma symptoms, headaches, and other ailments from mold, especially when certain strains are present.

The two most common and problematic types of mold found in residences are:

Stachybotrys chartarum  Otherwise known as toxic black mold, this strain grows in moist dark environments, such as in basements, damp framing, and water-damaged drywall.

Aspergillus  A family of molds, and it is probably more common than black mold. It grows in most of the same places as Stachybotrys chartarum and can be equally or more dangerous, because it’s lighter and more easily airborne.

There is no guarantee that either of these species are growing in a mold colony in your home. But, any mold colony growing in a dark, wet place in a dwelling unit is suspect, and it’s difficult to claim that toxic strains are absent without proof. Testing for mold strains requires a detailed inspection with a microscope, which usually isn’t practical.

Laws on mold remediation

There’s no federal law setting permissible limits or tolerance standards on mold in residential buildings. Only six states—California, Indiana, Maryland, Virginia, New Jersey, and Texas—have passed laws regulating mold levels in indoor environments. In Virginia, the law expressly requires the landlord to: “…maintain the premises in such a condition as to prevent the accumulation of moisture and the growth of mold, and to promptly respond to any notices from a tenant as provided in subdivision.”

While most states do not specifically legislate mold, they do require landlords to disclose potentially hazardous conditions at the time a lease agreement is signed. They also require landlords to correct any conditions that make a dwelling uninhabitable––toxic mold is arguably one of those conditions.

Some municipalities have laws that clearly define a landlord’s responsibilities:

Who should clean it up?

Any mold resulting from a plumbing or structural leak should be addressed by the landlord as part of the repair. But should a landlord feel compelled to respond to a mold problem caused by unsanitary domestic habits? Probably not.

Landlords aren’t required to provide cleaning services, and to insist on doing so would constitute an invasion of privacy. For example, it would be reasonable to expect a tenant to clean up a mold colony growing in a corner in which he or she habitually throws damp towels.

Between these two extremes, however, are many gray areas. For example, mold often grows inside drains that habitually clog. A clogged drain is usually caused by what goes in the drain, not the drain itself. Mold may also grow in a poorly ventilated crawl space, but the lack of ventilation may be due to piles of stored belongings. Mold can also grow along window sills, if the window is drafty and lets in moisture.

Here are some industry standards on who holds the responsibility of mold remediation. But know that each county, or judge, might interpret these situations differently.

Situation Responsibility Why
Mold on the ceiling due to leaky roof Landlord The landlord is responsible for roof leaks.
Mold seeping through basement walls Landlord The landlord is responsible for cracks in the foundation.
Mold caused by leaky pipe Landlord Leaky pipes are usually always the landlord’s responsibility.
Any mold present at move-in Landlord Landlord must provide a clean, safe unit
Surface mold on furniture Tenant The tenant must ensure the house is being ventilated regularly.
Mold on shower tiles or bathtub Tenant Tenant is responsible for regular cleanings, which will prevent this.
Mold on window sills Tenant This is caused by condensation and lack of ventilation.
Mold on drywall where wet towels are typically kept Tenant The wet towel is the cause.