What Should You Do If Your Rental Has Mold?

When a tenant reports mold, inspect promptly, find and fix the water source, and then clean up the growth. The EPA says a patch smaller than about 10 square feet is usually a job you or a handyman can handle and directs readers with larger areas to its fuller remediation guidance. Sewage damage or mold in the heating and cooling system call for a professional. You are usually liable when mold grows from a leak or defect you knew about and left unrepaired, but tenant fault does not necessarily end your duty to arrange repairs. No federal law sets a mold limit for homes, so your duties come from state habitability law, local housing codes, and a few state mold statutes.

When are you liable for mold, and when is the tenant?

Mold cannot grow without moisture, so responsibility for repair costs usually follows whoever controlled the water problem and failed to fix it.

You are likely responsible when:

• A roof, plumbing, window, or foundation leak you were told about, or would have found on a reasonable inspection, caused the growth.
• A building problem you control keeps an area wet, such as a broken bathroom exhaust fan, a clogged air conditioning drain line, or gutters that dump water against the foundation.
• The mold puts the unit below your state's habitability standard. California, for example, lists visible mold growth, as determined by a health officer or code enforcement officer, as a substandard housing condition under Health and Safety Code section 17920.3. Minor mold on surfaces that get wet in normal use, such as a shower, does not count.

The tenant is likely responsible for repair costs when their own conduct created the moisture, such as letting a tub overflow or misusing plumbing fixtures. In NYC, you must still keep the premises in good repair even when the tenant is responsible for the cost. California states both sides in Civil Code section 1941.7: your duty to repair mold does not arise until you have notice of it, and it does not arise if the tenant's breach of their own duties under section 1941.2, such as keeping the unit clean and using plumbing properly, caused the problem.

If mold you should have fixed makes a tenant sick, the tenant can sue under your state's negligence rules for medical costs and other losses. The EPA notes that mold can cause allergic reactions in sensitive people, and that dead mold can still trigger them, which is why cleanup means physically removing the growth. The general rules on landlord negligence and habitability are in your key liabilities as a landlord.

Why should you not wait to address mold?

Delay raises both the repair bill and your legal exposure.

• Repair cost. The EPA advises drying water-damaged areas within 24 to 48 hours to prevent mold growth. Once mold sets in, porous materials such as drywall, carpet, and ceiling tiles may have to be thrown away rather than cleaned.
• Notice. After a tenant reports mold, the question in a dispute becomes whether you acted within a reasonable time. A slow response can turn a cleanup into a habitability claim. Depending on the state, the tenant may then be able to repair and deduct, withhold rent, or end the lease. State deadlines and tenant remedies are in how much maintenance and repair the law requires.
• Code enforcement. Local inspectors can cite you, and violation notices carry fixed deadlines. In New York City, the housing agency gives owners 90 days to correct minor mold, 30 days for moderate mold, and 21 days for severe mold.

Do not hold off while you wait to learn whether the mold is a "toxic" type. The EPA says sampling is usually unnecessary when you can see the growth. Either way, the response is to fix the moisture and remove the mold.

What steps should you take when a tenant reports mold?

1. Reply in writing and set an inspection time. Give the entry notice your state requires. In California, entry to repair mold follows the state's general entry rules.
2. Find the source. Check under sinks and around tubs and toilets, window frames, the ceiling below the roof or the unit above, air conditioning drip pans and drain lines, and cold surfaces such as uninsulated pipes and exterior walls that collect condensation.
3. Fix the water problem first. The EPA warns that if you clean up mold but do not fix the water problem, the mold will most likely come back.
4. Clean or remove the growth. Scrub hard surfaces with detergent and water, then dry them completely. Moldy porous materials such as carpet and ceiling tiles may need to be discarded if the mold cannot be removed completely. Do not paint or caulk over mold.
5. Dry the area with fans or a dehumidifier so materials stay dry.
6. Document everything. Keep the tenant's report, your reply, photos before and after, and every invoice. That record shows when you had notice and how fast you acted.

Should you remove the mold yourself?

You can if the moldy area is smaller than about 10 square feet, roughly a 3-foot by 3-foot patch, and it came from clean water. The EPA recommends gloves, goggles, and an N-95 respirator during cleanup. It does not recommend bleach or other biocides as a routine cleanup step. If you do use bleach, never mix it with ammonia or cleaners that contain ammonia, and open windows for fresh air.

For mold covering more than about 10 square feet or extensive water damage, the EPA directs you to its Mold Remediation in Schools and Commercial Buildings guide.

Hire a professional instead when:

• The water came from sewage or another contaminated source.
• You know or suspect the heating, ventilation, and air conditioning (HVAC) system is contaminated. The EPA says not to run the system if you know or suspect it is contaminated.
• The unit smells moldy but you cannot find the source, which can mean hidden mold inside walls or ceilings.

Choose a contractor with mold cleanup experience and check references. In Texas and New York, also confirm the state license described below.

Is mold testing worth paying for?

Usually not. There are no EPA or other federal limits for mold in homes, so a lab result cannot show whether a unit passes or fails a standard, and when mold is visible the EPA says sampling is unnecessary in most cases. Testing is worth the cost in a few situations the EPA identifies:

• The source of the mold is unclear, such as a moldy smell with no visible growth.
• A tenant has raised health complaints, or a lawsuit is involved.
• You want sampling before and after a professional cleanup to confirm the cleanup worked.

The EPA says sampling should be done by professionals with experience designing sampling plans and reading the results.

What state and local mold rules apply?

Where your state has no mold-specific statute, mold falls under general habitability law and local housing codes. These states and cities add mold-specific rules:

California's repair standards and tenant remedies are in California maintenance and repair obligations, and Washington's repair deadlines are in Washington maintenance and repair obligations. Check your city's housing code too, since local rules can be stricter than state law. Once the unit is clean, the moisture-control routine in how to prevent mold in your rental keeps the problem from coming back.