top of page



How to Handle Mold Problems

Residents/Renters with Moldy or Damp Dwellings

Visible mold is covered by the California Housing Code: visible residential mold at a level that may be hazardous to occupants is a condition that makes housing substandard. The visible mold can be cited by local code enforcement so that the owner is required to remediate the problem. Often the challenge for the renter, when the owner is unresponsive to requests to fix the problem, is to identify the proper code enforcement authority to enforce the California Housing Code. Note that our small group at CDPH does not do enforcement or inspections, but provides information to the public and does research to assist the protection of the public.

Dampness in your home living spaces has long been listed as a condition making a home substandard to a code inspector.  As of January 1, 2016, mold is also a condition that makes a home substandard in California. The owner of a rental property cited as substandard by a local (city or county) code inspector is required to repair the substandard condition. Below are the parts of the California Residential Building Code that refer to dampness and mold.

Any building or portion thereof including any dwelling unit, guestroom or suite of rooms, or the premises on which the same is located, in which there exists any of the following listed conditions to an extent that endangers the life, limb, health, property, safety, or welfare of the public or the occupants thereof shall be deemed and hereby is declared to be a substandard building:

(11) Dampness of habitable rooms.

(13) Visible mold growth, as determined by a health officer or a code enforcement officer, as defined in Section 829.5 of the Penal Code, excluding the presence of mold that is minor and found on surfaces that can accumulate moisture as part of their properly functioning and intended use.

78824278 - Moldy window
574132570 - Moldy wall


It is important to note that realtors should be knowledgeable about mold and its potential impact on a property. They should be able to identify signs of mold during property inspections and advise clients on how to properly address any mold issues.  It is also recommended that realtors work with certified inspectors or remediation professionals to ensure the safety and well-being of their clients.

Mold litigation has expanded, and is now being brought by property owners/buyers, employees, tenants, or merely building occupants dealing with mold in real estate. These claims gained a lot of publicity (for example, the Ed McMahon lawsuit). Yet, the science regarding mold and whether it can cause significant or permanent health effects is not established. Specifically, when exposure to mold stops, the symptoms disappear, like most allergies.

Mold Issues that Grow into Big Lawsuits

Mold cases start with blaming the defendants for creating the moisture that allows mold to grow. Some cases, however, also allege knowledge and failure to disclose, and others allege failure to repair or eradicate the mold properly once it’s discovered.

Plaintiffs in mold litigation allege a variety of illnesses and adverse health effects: from headaches, nausea, fatigue, asthma, hay fever-like symptoms (runny nose and scratchy throat), and respiratory problems, to fibromyalgia, chronic fatigue syndrome, reactive airway dysfunction syndrome, difficulty with memory and other cognitive functions and even cancer. The more common allergic reactions in individuals are coughing, sneezing, and breathing problems. The soft tissues around the nose, mouth, trachea, and lungs are extremely vulnerable to mycotoxin contamination.

Yet, there is a lack of scientific consensus on the more seriously alleged illnesses and what level of mold exposure may cause such illnesses. The U.S. Centers for Disease Control and Prevention (CDC) website states that a causal link between the presence of the toxic mold and pulmonary hemorrhage or memory loss has not been proven.


In addition to the illness in humans, mycotoxins also cause a significant amount of property damage. Once inside, mold can contaminate anything in the surrounding area, including clothing, furniture, and works of art. Once contaminated, these items usually have to be destroyed. Building materials and fixtures are also fertile ground for mold growth. Building material typically must be removed and replaced, which is quite costly.

Mold Disclosures

As a result of many mold cases and large verdicts, some insurance companies have changed their coverages and either exclude mold claims or offer sub-limits only for mold claims. In California, the California Association of real estate licensees created a mold disclosure that each buyer receives during a purchase transaction, which explains that mold can arise where there is water intrusion; buyers are recommended to obtain mold tests if they learn of past water intrusion. Some molds cannot be seen (they may exist behind drywall, in the carpet, or under the subfloor), so an air sample must be performed to detect mold spores in the air.

Currently, there are no government or industry standards (including from the Environmental Protection Agency or EPA) that specify allowable or acceptable levels of indoor, airborne molds.  However, the EPA issued a guidance document for mold remediation projects that provides some general guidelines for evaluating and responding to an indoor mold problem.

Protect Yourself & Your Clients

It’s important to consider any water intrusion as a risk. Property owners (sellers) and property managers must also understand how to treat mold-infested areas once it’s discovered.


Disclose any visible water intrusion or mold, and any past water intrusion or mold problems.

132207042 - Moldy windowsill
79011044 - Moldy Wall

Property Managers:

Property Manager and Homeowner’s Responsibilities for Mold Disclosure

Since mold is such a prevalent issue in California, homeowners, property managers, and landlords have certain obligations related to mold growth in their property that are known as California mold disclosure laws. In California, landlords are responsible for maintaining safe living conditions for their tenants, called an ‘implied warranty of habitability’ for every lease in California. Unfortunately, mold breaches this implied warranty and as such, mold needs to be remediated immediately.

What are California’s State Laws About Mold Disclosure?

The Toxic Mold Protection Act of 2001 (California Health and Safety Code §§ 26100 –26156)

According to the Toxic Mold Protection Act of 2001 landlords are required to provide tenants with a mold disclosure before a lease is signed. With that, mold disclosure requirement is applicable under the following conditions:

  • A unit has an excess of mold,

  • Mold exceeds permissible limits, and

  • Mold poses a health threat to the tenant


Issuing a verbal warning to prospective tenants is not enough, and landlords are required to provide their tenants with all this information “in writing”. Since 2016, California has included mold in its State Housing Law and legislation has deemed visible mold as a health and safety concern, and it is enforceable as substandard housing.

How Long Do Property Managers Have to Remove the Mold?

According to California law, landlords and property managers have thirty (30) days to remove mold after being notified by a tenant. As far as the mold removal process, landlords are required to rid of not only visible mold but underlying issues that may be causing the mold issue. For example, if mold is being caused by leaky plumbing, the landlord is responsible for not only cleaning up the mold but fixing the leak, as well.

What are Tenants’ Responsibilities for Mold Issues?

Tenants are responsible for maintaining a clean and damp-free living space as much as possible. Tenants should always immediately notify their landlord or property manager if:

  • Sinks, toilets, and other appliances overflow,

  • Windows are not able to stave-off rainwater,

  • Their living space lacks proper ventilation, and

  • A dehumidifier is necessary to maintain a damp-free home

Additionally, daily house wear and tear is not a landlord or property manager’s responsibility.

Are Landlords Responsible for Mold Issues Caused by Tenants?

If a landlord suspects tenants of causing a mold outbreak, the landlord can deduct the costs of mold remediation from the tenant’s security deposit. If a landlord or property manager believes a departing tenant caused a mold problem (beyond ordinary wear and tear) in an apartment or rental unit, they may deduct cleaning costs from the tenant’s security deposit. Per California law, landlords are allowed to do this as long as they provide the tenant with a written explanation of the mold damage costs (along with any other claimed damages) within 21 days of the tenant’s lease termination. If the costs for the mold remediation total less than the security deposit, the landlord, or property management company must return the remainder of the deposit to the tenant along with the written documentation of damage deductions. (Cal. Civ. Code § 1950.5(g)(1) (2021).)

If you believe your residential or commercial property contains excess mold, you should consider having a mold inspection performed on your property.

Property Managers

Schedule an Inspection Today!

bottom of page