How do I find the source of mold in my house?

Author: Miss Camille Labadie  |  Last update: Monday, September 15, 2025

Mold can grow anywhere there is adequate moisture or a water problem. The best way to find mold is to look for signs of mold growth, water staining, warping, or to follow your nose to the source of the odor. It may be necessary to look behind and underneath surfaces, such as carpets, wallpaper, cabinets, and walls.

How to find out where mold is coming from?

Most often, a mold problem will be readily identified by a musty smell that becomes obvious in damp environments. Mold also likes to play hide and seek, so if you suspect there is a problem, then check under carpets, behind drywall, inside ductwork, in between bathroom tiles and in other moisture-prone areas.

Where is mold most commonly found in homes?

To prevent mold, toxic mold, and mildew, make sure you are inspecting these 14 places where mold can thrive in your home.
  • Basement. Your basement is likely the most common place where you will see mold. ...
  • Bathrooms. ...
  • Kitchen. ...
  • Attics. ...
  • Crawl Space. ...
  • Laundry Rooms. ...
  • Underneath Flooring. ...
  • Air Conditioners.

What if I can smell mold but can't find it?

When a homeowner smells mold but visual clues are invisible to the naked eye, then mold testing can be performed by a professional to locate the colonies. A mold testing kit can also be inexpensively purchased from the local hardware store and utilized by the homeowner.

How to get rid of mold if you can't see it?

How do I get rid of hidden mold in my house? Find what is causing the mold growth such as moisture problems and fix it. Also, clean up the mold up to its roots by using soap and water or other natural solutions like vinegar, hydrogen peroxide, and baking soda.

1. When Mold in the Home Is a Problem (English)

How to tell if mold is behind drywall?

Musty Smell

If you think there's mold in your walls, get on your hands and knees and smell the electrical outlets. This might sound silly, but it may help you sense mold if it's growing within walls. Outlets have better access to the area behind the walls. Thus, smelling them can help identify the mold problem.

What kills 100% of mold?

Hydrogen peroxide, commonly used to disinfect wounds, is active against a wide variety of micro-organisms including mold. It acts by releasing oxygen at a rapid rate, which kills mold by oxidizing the surface and breaking down proteins and DNA.

What are signs of mold sickness?

Although symptoms can vary, the most common symptoms seen in people exposed to mold indoors include:
  • Nasal and sinus congestion.
  • Eye irritation, such as itchy, red, watery eyes.
  • Wheezing and difficulty breathing.
  • Cough.
  • Throat irritation.
  • Skin irritation, such as a rash.
  • Headache.

Are there mold detectors?

The Biomatrix mold monitor is more than the most technologically advanced smart home mold detector on the market. With the purchase of a Biomatrix device, your system will be monitored by a team of specialists, ensuring that your home is scanned for signs of trouble 24/7.

Does mold behind walls affect you?

Extensive mold in the home can become dangerous. The reason is that some species of mold produce mycotoxin, a substance that leads to headaches, problems with breathing, and even damage in the neurological system. Other symptoms may even include an annoying odor, sneezing, or a runny nose.

How to check for mold in the air in your house?

The two most common methods used to identify a mold problem are mold test kits or air testing sensors. These kits include the necessary air test devices, chemical strips, or Petri dishes and are available at department stores or online. They'll also come with an instruction manual for any brand-specific guidelines.

Does homeowners insurance cover mold?

Homeowners insurance doesn't usually cover mold damage or removal unless it's the result of a covered peril. If the mold in your residence was caused by something sudden or accidental, such as a bursting pipe or some other covered incident on your policy, you may be protected.

What is the number one cause of mold?

1. Insufficient Ventilation. In areas like bathrooms and older homes lacking proper ventilation and exhaust fans, excess moisture from hot showers can get trapped. This trapped humidity settles on various surfaces, creating a conducive environment for mold growth.

How do I permanently get rid of mold in my house?

Spray the area with a mixture of water and vinegar - half water, half vinegar. Next, scrub to remove all traces of the mold. For removal of black and white mold, spray the area with the half water and half vinegar solution.

Is there a way to test a home for mold?

Air sampling is the most common type of mold testing. It involves collecting air samples from various areas of your home and analyzing them for the presence of mold spores. Air sampling can identify the type and concentration of mold spores in your home.

Can air purifiers help with mold?

Mold is an obvious health risk in any home, but investing in an air purifier can help limit your exposure. The best among them will ideally offer HEPA-level filtration, with this level of filtration being able to trap up to 99.97% of airborne particles down to 0.3 microns in diameter.

How do I find hidden mold in my house?

Use Your Nose: Mold often produces a musty odor, so follow your nose to detect any unusual smells in different areas of your home. Look for Water Damage: Check for any visible signs of water damage such as discoloration, peeling paint, or water stains on walls, ceilings, and floors, as these can indicate hidden mold.

Is there an app to detect mold in your house?

Mold Finder AI makes mold inspection fast, easy, and reliable. Whether you're concerned about black mold or any other mold issue, our advanced AI technology will help you detect and analyze mold in seconds. Simply snap a photo or upload one from your gallery, and Mold Finder AI will do the rest!

What does black mold smell like?

Toxic black mold growth has a more potent and identifiable smell, like the smell of decay, wet soil, or rot. Visually, it may be greenish-black, grayish-black, slimy, or more furry than other forms of mold or mildew.

How to tell if your house is toxic?

If you suspect your asthma worsens or is more severe than usual, contact your doctor or medical professional.
  1. Bad Smells In The Home. When there's a bad smell in the home, you can tell. ...
  2. Peeling Wallpaper. ...
  3. Spots On The Wall. ...
  4. Bad Allergies Won't Go Away. ...
  5. Visible Mold Growth. ...
  6. Past Water Damage.

What happens if you live in a house with mold?

Adults who live in moldy homes are up to 50 percent more likely to develop asthma. Children are even more likely to develop health issues like asthma and rhinitis. Mold exposure has also been associated with other upper respiratory infections, with symptoms that can range from sinus infections to sore throats.

How long does it take to get sick from mold exposure?

According to the CDC, people usually experience their first symptoms within 2 to 9 hours of their first exposure. On the other hand, some people could go for weeks or months before feeling sick if their exposure is limited enough. This is why it is also important to check damp, dark areas of your home for mold.

What draws out mold?

Mix a solution that's equal parts white vinegar and cold water in a spray bottle. Spray or apply the vinegar and water mixture directly to the moldy areas. Using a scrub brush with a long handle, scrub the moldy areas vigorously in a circular motion. Continue scrubbing until you remove the mold stains.

Who pays for mold remediation?

If there is a covered condition that the homeowner's insurance policy covers that causes mold, then the insurance company will cover mold remediation. Excess water from a natural cause like a roof leaking after a rain storm is usually covered by a homeowners insurance policy.

What degrees kills mold?

Most yeasts and molds are heat-sensitive and destroyed by heat treatments at temperatures of 140-160°F (60-71°C). Some molds make heat-resistant spores, however, and can survive heat treatments in pickled vegetable products. These molds, however, require oxygen to grow.

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