What Are Signs Of Mold In Your House (13 Signs To Look For)

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Homes are supposed to shield us from the harmful things outside like water, wind, and extreme temperatures. Sometimes, however, our houses fail to provide the necessary shelter and moisture enters our house and allows mold to grow.

If there is adequate moisture mold can grow in our bathrooms, kitchens, basements, and attics. Mold can also grow undetected inside of our walls.

As someone who grew up with allergies, I’m vigilant about monitoring moisture inside my home. I have felt the effects of mold allergy symptoms and suffered for a long time.

In addition to health problems, mold can cause structural damage and damage to furniture inside a house.

Below I’ll share 13 important signs of mold in your house. Growing up I remember seeing mold in my bathroom and near windows. At the time I didn’t realize it but the fungus was affecting the quality of my life.

13 Signs Of Mold In Your House

#1 Visible Mold

One of our most valuable senses is sight. Sight gives us the ability to distinguish what is safe from what is dangerous.

Our sight also allows us to anticipate unsafe situations and fix them.

Many molds found in the house can be seen and easily cleaned. A visual inspection of your basement, living area, and attic should be part of a routine to avoid mold growth.

Don’t ignore mold if you see it. Take the necessary steps to remove its growth!

#2 Humidity

Humidity plays a major role in the development of mold. Without humidity mold’s growth will be limited.

Humidity is the reason we often find mold in the bathroom (showering), in the basement, and around windows. Moisture spurs its growth and if the humidity is not addressed mold can spread quickly.

Having a fan in the bathroom works great! A dehumidifier in the basement also helps to remove moisture from the air while making your home more comfortable.

Humidity is usually higher in hot summers in the East, South, and Mid-West of America.

#3 Moisture (Walls, Pipes, Leaks)

Moisture can appear in a number of places. As we mentioned above, humidity can create moisture in a house but there are other sources as well.

A leaky pipe can create a flood of water below a house and it can go undetected for months or years.

The last house I lived in had a leaky pipe underneath the house and slowly dripped for over a year. The leak didn’t cause flooding however it did create the perfect environment for mold to grow.

Cracks in a basement wall can cause moisture to seep into a house. Most basements have sump pumps that collect water and redirect it outside of the house.

Also, be sure to check your window and door seals to make sure water isn’t entering the house.

#4 Health Symptoms

Did you know that mold is a major allergen in the U.S.? One of the most frustrating problems of mold is its effect on our health.

People often disregard mold in a bathroom or in a basement because they don’t believe it’s a problem, however, your health might be suffering because of it.

I happened to be allergic to many types of mold but never realized it. Typical allergy symptoms included:

  • Fatigue
  • Rashes
  • Congestion
  • Itchy skin and eyes
  • Watery eyes
  • Asthma

I was allergic to a number of indoor allergens, especially dust mites, however, I know that mold was also a factor in my health.

Get rid of mold in your house and you’ll likely be improving your health! signs of mold in your house

#5 Flooding From Outside

Hard rains occur seasonally in much of the U.S. and occasionally there is flooding. If water enters your home you can count on mold growth. In recent years places like New Orleans and Houston have experienced flooding, costing homeowners millions of dollars.

It’s a horrible experience to go through because it can ruin a home.

If flooding occurs in your house be sure to dry things out as soon as possible. Remove carpeting, rugs, and furniture and put them in the sun to dry. Your walls may or may not be saved depending on the severity of the flooding.

Industrial fans and dehumidifiers can be useful to dry your home out as quickly as possible. Ventilation is also key to move air through the house (open windows and doors).

#6 Basement

Do you have a basement? Not all houses have basements but those that do should be aware of potential problems with moisture.

Moisture problems occur in basements because they are built into the soil. The water level of your geographical area matters and the type of soil plays a role in whether you might have moisture issues.

It’s common for basements to develop cracks in the walls where moisture can seep through. Be sure to check your “sump pump” to make sure it’s working properly.

Some families keep a dehumidifier in the basement that reduces air moisture to a more comfortable level.

#7 Smell

Another one of our senses is the ability to smell. Dampness has a certain smell that is recognizable. I occasionally smell dampness under my sink or when I’m in a damp, dark place (under a house).

Investigate your house if you smell something and figure out ways to dry the area out (open a window, use a fan etc.)

#8 Roof Leaks

A roof is supposed to keep moisture out but sometimes the roof leaks. Occasional leaking will occur but the important thing is fixing the issue quickly.

If moisture is allowed to enter your attic it can provide the perfect storm for mold growth. The problem with mold in the attic is we rarely venture into the attic and might not recognize it for months.

During those months it can still affect our health and the structure of the house.

Once mold begins growing on wood, brick, or insulation it’s a hassle to remove. Catch the leak in the roof before the problems begin.

#9 Condensation Around The Windows

Mold is often found near windows. It may not be a lot of mold but even a small amount of mold can damage paint and cause health problems.

Mold is less likely to occur on newer windows. Condensation is common on old, single pane windows but rarely on dual pane windows.

Also, make sure the window is set correctly so air isn’t entering the house through the sides of the window.

#10 Water Marks

Water within walls will often display watermarks. This can be a surprising and worrisome thing to see, however, it’s important to follow it up.

Drywall and wood walls will show water marks but bricks and tile won’t usually display marks.

Watermarks might be more visible on the bottom edge of walls where there was flooding or they can flow down from a multi-story home if water is leaking from above. This can occur in a residential apartment and condo buildings.

If you see water marks you’ll definitely want to investigate for mold growth. Mold loves moisture!

#11 Warping or Paint Peeling

Warping or paint peeling doesn’t mean you have mold but it’s another sign of moisture. If the moisture doesn’t dry up, mold will surely grow.

If you see warping or paint peeling you may have to remove a section of a wall to see what’s happening within.

Once you find the cause, fix it and repaint or replace the warping.

#12 Rust

Over time, moisture will cause the metal to rust. Rust can be seen on pipes (sometimes from condensation). Rust can also be seen on nails and hinges.

Rust doesn’t mean there is mold, but it means there may be moisture. Investigate!

#13 Closed Home (No Ventilation)

If you don’t have a fan in your bathroom you likely understand how mold forms without ventilation. Mold will grow on the ceiling in the bathroom because there’s plenty of humidity and no place for it to go.

Fans, windows, doors can all be used to promote circulation and air out a home. Installing a fan in the bathroom might cost a few hundred dollars but it will reduce the chance of mold in your bathroom and thereby save you time and ensure your health.

Make a point to open doors and windows on nice days. If you prefer not to open your windows, try turning your HVAC on and running air through the house a few times a week. The vent is sufficient to promote circulation and reduce the chance of mold growth!


Mold growth can be a major problem for the structural integrity of our homes and even impact our health.

After being diagnosed with allergies I realized that I had overlooked the hazards of mold for a long time.

Mold has a tendency to grow in bathrooms, basements, and around attics.  Where there is moisture mold has an opportunity to multiply.

Ventilation is essential to make sure mold doesn’t grow.  If you live in a humid area consider investing in a dehumidifier that will reduce the amount of moisture in the air.  Consider getting a fan in your bathroom too!

Our senses can help us detect if moisture is spurring mold growth.  Look at walls for watermarks, observe condensation along windows and visually inspect your attic a few times each year to make sure you don’t have leaks.

If moisture and mold are in your home it may produce a damp, musty smell.  Follow your nose and fix the problem!

Dust Mite Solutions aims to inform and educate others on indoor allergens.  Whether it’s mold, dust mites, or pet allergies it’s important you’re aware of the symptoms and how to reduce them.

Manage the mold in your home and feel better about breathing!

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