What you can do to check for mold yourself

You can spot visible mold without special equipment. Look in bathrooms, under sinks, around windows, and in corners where walls meet the floor — anywhere that stays damp. Mold appears as black, green, or white spots or fuzzy patches. If you see it, take a photo with the date visible and report it to your landlord in writing (email counts). Do not try to clean it yourself; mold spores spread when disturbed, and the underlying moisture problem needs to be fixed first.

For mold you suspect but cannot see, a mold test kit from a hardware store lets you collect a sample yourself. These kits typically cost $15 to $40. You swab or tape a surface, seal the sample, mail it to a lab, and receive results in one to two weeks. The lab tells you whether mold is present and sometimes what type. This gives you documentation to show your landlord, though it does not tell you how serious the problem is or where else mold might be hiding.

Smell is also a clue. Mold has a musty, earthy odor. If you notice it in one room or area, that is where moisture is collecting. Open windows to air out the space while you investigate, but do not ignore the smell — it means moisture is present whether you can see mold yet or not.

Key Takeaways

  • Visible mold in bathrooms, under sinks, or around windows should be photographed and reported to your landlord in writing; do not attempt to clean it yourself.
  • Over-the-counter mold test kits cost $15 to $40, require you to mail a sample to a lab, and return results in one to two weeks.
  • A musty smell in one area of your apartment signals moisture buildup and should prompt you to investigate and report the problem to your landlord.
  • Professional mold inspections by a certified inspector cost $300 to $700 and are most useful when you suspect a large or hidden problem.
  • Your landlord is responsible for fixing moisture and mold problems; your role is to document what you find and report it clearly.

When to call a professional mold inspector

A certified mold inspector uses moisture meters, thermal imaging, and air sampling to find mold you cannot see and measure how much is present. This costs $300 to $700 depending on apartment size and what the inspector needs to check. You pay for this yourself unless your lease or local law says the landlord must. An inspection makes sense if you have persistent health symptoms (coughing, wheezing, allergies that worsen indoors), a musty smell you cannot locate, or water damage you know about but cannot assess.

To find an inspector, search online for "certified mold inspector" plus your city, or ask your doctor or local health department for a referral. Verify they hold a current certification from a recognized body like the American Council for Accredited Certification (ACAC) or the Indoor Air Quality Association (IAQA). Ask for references and a written estimate before they start. Once you have the report, send a copy to your landlord along with a written request to fix the problem.

How to document mold for your landlord

Written notice is essential. Email your landlord or property manager describing what you see, where it is, and when you first noticed it. Include photos with dates. If you took a mold test kit sample, mention that in the email. Keep a copy of every message you send. This creates a record that you reported the problem, which matters if the mold worsens or causes damage to your belongings.

If your landlord does not respond within a reasonable time (usually 7 to 14 days depending on your state), send a follow-up email referencing your first message. Some states require landlords to address mold within a specific timeframe; check your state or local housing authority website to learn what applies where you live. If the problem persists and your landlord does not act, you may have the right to withhold rent, break your lease, or file a complaint with your local housing authority — but only after you have documented your attempts to notify them.

Moisture problems that lead to mold

Mold grows where moisture stays. Common sources in apartments are bathroom ventilation that does not work (or vents into the attic instead of outside), leaky pipes under sinks, condensation on windows in winter, roof leaks, and poor drainage around the building foundation. If you see mold, the moisture source must be fixed or the mold will return. This is your landlord's responsibility, not yours.

You can reduce moisture in your space by running the bathroom exhaust fan during and for 20 minutes after showers, wiping down windows on cold mornings, opening windows on dry days, and not blocking air vents with furniture. These steps help but do not solve a structural problem. If your apartment stays damp no matter what you do, the building itself has an issue that only your landlord can fix.

Health effects and when to see a doctor

Mold exposure can trigger allergies, asthma, and respiratory irritation, especially in people with existing lung conditions or weakened immune systems. Symptoms include coughing, wheezing, nasal congestion, itchy eyes, and shortness of breath. If you develop or notice these symptoms getting worse after moving into an apartment with visible mold or a musty smell, see your doctor and mention the mold. Your doctor can test for mold sensitivity and recommend treatment.

Tell your landlord about health symptoms in writing. This strengthens your case if you later need to break your lease or file a complaint. Some states consider uninhabitable conditions — including uncorrected mold problems — grounds for rent withholding or lease termination, but you must have documented the problem and given your landlord time to fix it first.

Your rights and next steps if mold is not addressed

Landlords are required by law in most states to maintain apartments in habitable condition, which includes controlling moisture and mold. If your landlord ignores your written reports, your options depend on where you live. Some states allow you to repair the problem yourself and deduct the cost from rent (called "repair and deduct"). Others let you withhold rent until the problem is fixed. A few allow you to break your lease without penalty if mold makes the apartment uninhabitable.

Before taking any of these steps, contact your local housing authority, tenant rights organization, or a lawyer who handles housing law. They can tell you exactly what your state and city allow. Many offer free or low-cost consultations. If you are in a rent-controlled building or receive housing vouchers, additional protections may explore. Document everything — photos, test results, emails, dates — because you will need proof that the problem exists and that you reported it.

Frequently Asked Questions

Can mold in an apartment make me sick?

Mold can trigger allergies, asthma, and respiratory symptoms, especially in people with existing lung conditions. Not everyone reacts the same way. If you develop coughing, wheezing, or congestion after noticing mold, see your doctor and mention the mold exposure. Your doctor can determine whether mold is the cause.

Do I have to pay for mold testing or removal?

Your landlord is responsible for fixing moisture and mold problems. You can pay for a test kit yourself to document the problem, but your landlord should pay for professional removal. If they refuse, check your state or local housing authority rules — some allow you to pay for repairs and deduct the cost from rent, but you must follow the correct process first.

What if I see mold but my landlord says it is just dirt?

Take a photo and, if you are unsure, use a mold test kit to confirm. A lab result gives you objective proof. Send the result to your landlord in writing. If they still refuse to act, contact your local housing authority or a tenant rights organization for guidance on your next steps.

How long does it take to get mold test results?

Over-the-counter test kits typically take one to two weeks after you mail the sample. Professional mold inspections give you a report within a few days. Lab turnaround varies by location and how busy the lab is, so ask when you order the kit.

Can I break my lease because of mold?

It depends on your state and how severe the problem is. Some states allow lease termination if mold makes the apartment uninhabitable, but you must document the problem, report it to your landlord in writing, and give them time to fix it first. Contact your local housing authority or a tenant rights lawyer to learn what applies where you live.